Home Automation Hangout 2021-04-18: UT61e multimeter WiFi hack, part 2

please [Music] good morning my superhuman friends ah if it seems like i'm kind of jittery and disorganized it's because i am but before i explain that um i acknowledge the traditional owners of this land i pay my respects to their elders past and present and to aboriginal elders and peoples from other communities who may be taking part in this live stream today so i was very nearly not here and right before right before going live i still didn't have my microphone working and other stuff so what happened was last week my imac died and it was while i was using it i was actually sitting here using it and all of a sudden it was like someone just pulled out the power cord so i'm pretty sure the power supply in it is dead and luckily my wife has an old imac that she hasn't used for a couple of years because she just does everything off a laptop so i wiped that and restored from time machine pulled my imac back up onto it so right now i'm using a lower spec imac than i have been using in the past and oh sorry i just noticed something was stuttering hopefully it's working but the result is that i've had to set permissions on everything so things like hdmi and audio and i was just trying to get things working so right before going live i still didn't even have hdmi capture working properly my logitech brio camera which is the one you're looking at me at right now was not working it was just a black screen so i've been frantically trying to make stuff work and i think we've got it hopefully you can hear me so good morning ingma cabletti oh good thanks dodgy austin david dustin bob p hmm bob bob p ah is that bob powers i hope it is um mike g'day so all right uh because i've been rushing i still feel like jittery and still trying to get everything sorted but we will get there okay couple of deep breaths what have i got oh and my obscene switcher is not set up so that's actually something that is worth getting going if i'm going to be showing stuff on the overhead camera and switching between cameras the scene switcher is useful so while while i make you wait i am going to just see if i can get this working color doesn't look right though no the um the logitech camera is not as great actually i can probably improve things a little bit because i have another light over here which will ah let's try this that throws a bit more light at the front at least so the camera doesn't have to work so hard all right touch portal uh oh aaron said ooh light switch controller in the background is the project progressing yes i'm going to talk about that that is one of the many squirrels that we all chose today so it wants to receive keystrokes from the application open system preferences this has been my world for the last week just about everything i do has been authorizing things to do what they want to do all of the sandboxing and security stuff in in mac os is useful but the result is that if you switch to a new computer all the things that you had running previously you've not got to re-authorize so i've just had to re-authorize touch portal so that i can get my obs scenes which are running okay i think it's going to be time to crack open a drink earlier today now it's probably trying to connect to the wrong ip address i think it is two one four okay so i have a new ip touch portal settings uh come on here we go it won't take that long i promise i'll get there uh 214 touch portal connect come on connect all right let's just switch to the desktop and see if this works yay obscene switcher is working looks like we're back in business folks alrighty so uh today oh ceon hey thanks for coming along um mike said my closet said switch to big sur yes i did because partly because well the um the imac my main imac is too old to run big sur it's um it's a very old machine so the one that i've switched to this imac that i'm using now is a couple of years newer this is a 2015 model imac but it's lower spec so it's newer than my normal imac but it's um it's only an i5 processor not an i7 processor and other uh it's spinning oh was it i think it might have a fusion drive my other imac had a an ssd so anyway ah all right where are we at yes we will get into some unity hacking because that is a fun thing but there are a couple of things i wanted to talk about first two things two squirrels and the very first squirrel is after last week's time zone change let's have a look at something i've been thinking about maybe radical like just changing the time of the live stream now there is going to be a this is going to be an example of survivor bias which is a really interesting concept you should check that out if you haven't come across it before survivor bias and bombers in world war ii so uh the 10 a.m sunday for me locally in melbourne live stream time works out pretty well i get a couple of hours then go to lunch it's a leisurely get up in the morning i don't have to rush to get up to live stream at you know see on time or anything ridiculous like that so uh i've been thinking about other sorry i'm pulling up stuff on my desktop which i'll show you in just a moment now oh my um uh browser is being very laggy the computer is working hard i wonder if i'm dropping frames don't know let's see what does obs think no it thinks it's okay it says zero dropped frame so far which is nice it's hanging in there all right so analytics anyway last week's change to the live stream time and then seeing something in google analytics made me come on subscribers watch time somewhere in in the analytics maybe it's in the audience section audience aha here we go okay so let's look at this so this is youtube studio for super house and this is the the back end so showing you all the stats of what's going on let's zoom that in a bit can we get a bit of zoom image happening make it easier to read not that much maybe about there and move it across here okay so this little heat map chart thing here got my attention and uh so what you're seeing here is time of day in my local time zone so day of the week and time of day and when my audience is online now the thing is that a lot of the views for my prepared and edited videos come from the us so the time zone kind of biases towards the us so what you can see is that the spots where most of my viewers are online is stuff like between uh you know 10 p.m and 4 a.m or 3 a.m so it's overnight through the midnight hours if i was doing night shift that would be the time to be live streaming because that's when people are around and look at this sunday 10 a.m where's 10 am right about here phew so this section here where i'd normally do the live stream is right when my viewers are not on youtube so uh now if i ask you this is the survivor bias thing if i ask you what time i should live stream it will tend to be um people who make it to this live stream are the people who can make it to the live stream and it suits their time and therefore they're going to be more likely to say stick with the current time so if i ask the existing audience i'm pretty sure you're all going to say stick to the current time but it may make sense to do something like go to [Music] maybe 8 p.m on a sunday just as a hypothetical so if i did a live stream between 8 and 10 p.m on sunday evening then more people are going to be online maybe that would be better maybe that would suit you as well i don't know so i pulled up this thing so this is um a really cool little time zone conversion thing so where are we sunday sunday if i go for sun the green one down the bottom if i go for sunday 8 p.m which is down here that makes it uh where are we in makes it midnight in germany which would kind of suck 11 a.m in the uk that would 11 a.m sunday that's kind of a relaxed time 6 a.m us eastern time makes it really early in the morning if you're you know west coast us and makes it comfortably in the evening if you're in china japan india you know all those sorts of areas and new zealand it would be 10 o'clock anyway i'm not deciding anything on that right now that is just something that i came across this chart and it just made me think hang on i'm live streaming right here in the worst possible time when people aren't online so hang on i gotta where are we zoo view actual size okay now i can go all right uh so austin said i think it would be worth it to shift the time and test it normally i think i see 50 to 150 people watching the stream live yeah that's pretty normal and mike says daylight savings time added to the mix see on so now you know specifically why i get up at 5 00 am to stream early on wednesday mornings yes that's dedication see on you are very dedicated uh i'm i'm not quite that um what's the word well dedicated i suppose is the word when it come what it comes down to is i'm doing this how do i put this in a nice way i don't want to put myself out i'm doing this because it's fun and i'm not doing it because i want to you know grow a huge audience or something like that and uh so i don't i think i would make the sacrifice that xion does of getting up at five o'clock in the morning in order to do a live stream so that's very admirable but um i'm not i'm not going to go to that much effort sorry uh okay um but then uh okay stay up looks like europe including uk seems to be your biggest audience overall um is what aaron said yeah so where are somewhere in here oh no look at this geographies united states not 12.9 percent united kingdom 8.3 australia 6.2 and of course australia is going to be slightly higher represented than you know just the the global average simply because uh that's where i am and i think a whole lot of the people that watch the channel are people that i know personally so it just comes from having your friends watch it which means it's people in your same time zone so uh dashboard while i'm in here what else is going on ah nothing much interesting yeah well for those who care there are stats i'm i'm happy to show any information oh look at this estimated revenue so 296 dollars that's the revenue for the month out of youtube so that includes uh that includes ads on videos and it also includes super chats and and that sort of thing and that can vary dramatically so often i'll get zero super chats sometimes i will get quite a few so i might get you know fifty dollars worth of super chats on a live stream sometimes and and that pushes up this estimated revenue so let's see actually revenue somewhere in here there should be some interesting figures okay playback based cpm that's really high 16.12 that's really high [Music] so rpm which is revenue per thousand m for melee for a thousand like millimeter it's the same sort of route as millimeter it's um a thousandth of a meter and rpm means revenue per thousand views so for every thousand views of my videos on average i get four dollars ten which is okay anyway uh oh you can see the uh the revenue has dropped off dramatically over the last few months this is a squirrel i didn't expect to chase this wasn't i wasn't going to be getting into all of this sort of stuff but look at this so this is revenue november and december 755.685 and i think this might be because there were some uh some big super chat contributions in those periods and that is what artificially pushed those numbers up but these numbers down here this is more like what my advertising revenue is so january 336 february 278 march back up to 337 april it's 140 so far where are we in april so it's the 18th of april we're most of the way through 140 so it's going to make it up into the 200 and something region in april anyway uh actual size there we go all right oh dodgy said 8pm would be fine hmm okay i would like um yeah watching in oh ben said watching in silence as my 20 month old grizzle's about going down for her day sleep so if i just hit mute and do this and maybe you know wave a lot then so that was one thing as i said there were two scrolls i wanted to chase one is the time oh and the other thing is working on this um this multimeter hacking thing it seems to me that there are really a couple of different types of live stream that i could do and i like the idea of doing two live streams a week and having them be for specific purposes so i could do one live stream like a sunday morning thing which is where i just talk to you about all sorts of rubbish and maybe get interesting people on hopefully and do some interviews or whatever so i've had a couple of people on doing interviews which i thought has been really fun i've enjoyed that and i need to do more of that and then do a different i love the live stream at a different time which is just working on a project things like this multimeter hack the sort of thing that i don't necessarily have to be talking continuously because with this live stream i kind of feel the pressure that it's like um being a radio dj you know the the last thing that a dj wants is dead air when there's silence so i have this i feel this pressure to just keep talking no matter what you know what else is going on and if i'm working on something then i have to keep talking so what i could do is have a different live stream which is more about working on projects and i'd be able to do things live and you know sit and think about things a little bit pause for a minute while uh while working solving problems and and getting feedback from the chat that i think would be a really fun thing to do i'd like to do that now and celtic beast said november and december equals everyone setting up automated christmas lights ah you that reminds me last week on the live stream this is kind of a squirrel kind of night the sign you can see it's working and there is no flicker towards the end so this is with the brightons turned right down it's down to like five percent brightness at the moment he says turn the mic gain up stop talking and we can listen to your brain cogs were it'll just be rusty gears grinding against each other yeah i can get a um a neural implant so last week i mentioned the sign and that it was working again but i never actually explained the outcome i we did that live hacking thing where we went through and found various problems but then after the live stream this really highlights one of the problems of of doing things live and trying to stay engaged while i'm working on things and i can't really think all that clearly while i'm doing it or while i'm trying to talk about what i'm doing so on that live stream a few weeks ago we spent a couple of hours messing around with the sign and found a few things and didn't really make a huge amount of progress and then after the live stream finished that sunday i just thought stuff it i'm just going to fix it and within like half an hour the sign was totally functional and fixed and it's just you know it's been up there since and um so what i ended up doing i wonder if i should pull it down and show you yeah let's do that this is the sign has been um quite a topic of discussion for a while so i'll show you how it all turned out i'm gonna take power out of it i've got this little xt 30 connector that i stuck on the back and in a moment we will switch to a different camera what are we going to do overhead overhead overhead now can we zoom out as far as possible well not necessarily as far as possible just zoom out a bit all right now the way james had this wired up originally i've got rubbish all over my bench get that out of the way was see these wires here the orange and green wires these came from little five volt dc regulators and there were multiple regulators across the back here so there was 12 volts being i can't quite see what you can see all right so 12 volts being fed in and then that was going to multiple uh yeah multiple 5 volt buck converters and that was being then fed into multiple places on the pcb so i've ended up going for a bit of a simpler approach so what i did you can see here in fact let's get that zoomed in because what you can see here is a big bridge between the planes on the pcb and maybe i'll take this out of the frame it might be a bit easier to see it's um it was glued in but i removed all the glue so that i could access it now what was going on was each of the three pcbs that are in this turn it around zoom out so we've got one pcb for super one pcb for the logo one pcb for house and they have they have a five volt power plane on one side i can't remember which is which but yeah five volt power plane on one side and they have the ground plane on the other side oh it must be five volts on the back ground on the front and so there were power connections to these boards coming from the different converters feeding into it so there were multiple converters feeding into each board but each board was being fed independently and uh well kind of independently the um these wires were all tied together all salted together so what i ended up doing was taking a bit of a sledgehammer to crack a nut approach and what i did was tie the planes together so on the back of this this is the five volt plane and i got out a scalpel and scratched off the solder mask on the pcbs like basically i scratched a strip off the solder mask straight across the joint between those two boards there we go in fact let's um see if i can get it under here will will this work i'll need to get some focus happening but i want minimal zoom and get a bit of focus what what's that looking at oh that is that is replaying a video right now no i don't want to be doing that i bumped the um how do i stop it i'm going to turn off the little camera it's got this stupid there we go goodbye and i'll turn it back on again it's got a a really annoying menu system in the camera now which way not that way bring it up better okay i think mildly better so what i did was just grab a scalpel and i scratched off the solder mask on both of these and then i got some really big thick chunky cable and soldered it directly across between the planes and that tied the planes together and you can see that i did that on uh on the back of the pcb and [Music] i did it on the front so you can see there is a tie across across here another one across here so effectively what it did was just make the ground plane on the front of the pcb one continuous ground plane and it made the power plane on the back of the pcbs one continuous power plane then i got this heavy gauge silicon coated wire this is good quality stuff that's used for drones and things i love this wire it's really good it's got a very what's the term not thread count but it's the number of cores so with wire you can have there is a specification for the cross section but that doesn't give you the whole picture you can have a single core cable with a large cross-section and it will carry a lot of power but it won't be very flexible at all or you can have a cable with just a few cores and it will be slightly flexible or you can have lots and lots of tiny cores the same equivalent cross section but the cable is very very flexible and that's usually what you have on things like multimeter leads where you want the cables to be really supple but still have very low resistance and you know good electrical characteristics so this cable which i really like is silicon coated and it has a very high number of cores so it is very flexible like it it's really wobbly and the silicon insulation is nice it's much nicer than that crappy pvc insulation that you see on a lot of things anyway so i got some of that cable and you can see i've hot glued on here for strain relief super high tech and connected directly to the power planes and i drilled a hole down here through the glue pass that one through bent it over and once again scratched away and sold it directly on there and i also added another we were adding caps on the live stream so those caps are still there and i added another one here and now what i do is feed five volts dc straight in here and it works so it's kind of a brute force solution to the problem but it got us there so um i ended up getting going for a high current 5 volt switch mode power supply which is down there somewhere behind the chair with a cable that goes up and it just sits up there all right um now one thing that i have not been able to figure out this seems like the most obvious thing ever but i just don't get it is where does wm how do you make wled save its settings there must be some obvious way to do it like a button that you click and i just haven't seen it because every time i power this up it comes up with a um with whatever its previously configured thing was and as you'll see it'll be orange and at full brightness so on camera now if you look at that that'll just be a big blur i'm sure sure you won't even be able to tell what is on that i have to turn the brightness way way down before the camera can distinguish individual things so if we come into here yes okay you can see my desktop and you can see the sign just it's right behind my head bad position all right so it always comes up with this default then if i go into no not config back new the ui confuses me so if i go for i don't know fire flicker that'll do turn the brightness way down what is fire flicker doing not very much all right how about fade no random colors ripple ripple rainbow come on no i need to find one that or maybe just rainbow yeah rainbow that's a good one but then you can see the motion in it and if i switch back to the front camera to make it a bit bigger see now you can see that it's distinctly the super house sign and all the colors are flowing through it looks much prettier i'll just uh bring the brightness down a fraction more if i can yeah something like that that looks kind of cool needs to be just a little bit brighter maybe there now you can definitely make it out and you can see the colors sliding across all right oh okay so uh steven said i don't know if you can change it from there but you can change it from the code okay so dustin said do you just want to set the default startup effect yes yes i do so what i would like um james said said did i miss the dmm stuff that board doesn't look like it's for the serial no it's not but it's kind of the thing that inspired the dmm project we haven't got to that yet we're squirrel chasing it's still early in the day so yeah basically what i would like to be able to do is just pick something what's pc mode oh pc mode i see so that's for the um if i come back to here yeah so right now it's set to rainbow the brightness is set nice and low and i just want to save this and make it so that whenever it powers up these settings are what it uses config led preferences scroll down to the defaults nice config led preferences defaults default duration [Music] cool mode oh okay no fade sunrise advanced am i looking in the wrong place default target brightness that's set to zero which oh that's timed light save it to a preset okay so set current preset cycle setting as boot default let's try that oh default brightness i'm going to set that to like 30 or something and set current cycle as bird default yes and save okay maybe this will fix it i don't know all right anyway that is getting slightly off topic peter hey good morning peter so peter says how's the multimeter hack going it's not yet um all right no we're still squirrel chasing so um all right multimeter hack now something interesting that just came up so when i posted last night on twitter saying that i was doing more of the hacking the multimeter hacking today i got a couple of responses saying that the ut61e seems to be either discontinued or not really available and so that got me yeah it got me wondering ut61e so before we go any further i mean i'm still going to do it because i've got the multimeters myself but i'm curious to know whether the ut61e has recently been discontinued and it looks like it's still listed on the meteor 620 flyout models comparisons still listed on the unit site so yeah i don't know let's have a look not damn bang good let's look at banggood and see if they've got the ut61a on here ut61e someone was mentioning that there were a few still available so that one is why is that one 95 and this one is 68 oh it's the different edition i see so that one is the ut61e plus ah so maybe this is what's going on let's um let's side by side these all right so the ut61e plus is the new model and this one says restocking will be available soon so this one is not available right now i've seen this available though in the past and the ut61e the non-plus version is available in stock ships in 24 hours so i don't know hopefully they don't discontinue the 61. what might be happening is that they are phasing in the 61e plus to replace the 61e but the 61e still seems to be available what i'd like to know is whether this one has uh let's see well they've got plus versions of the b and the d as well now yeah it's probably just new generation stuff i wonder if it's got the optical interface on the back let's see can we see any specs on here optional accessories oh bluetooth plug in well then maybe i should just get myself ut 61e plus and set up bluetooth i could i could make a bluetooth to mqtt gateway and solve the problem uh yeah in many ways that's actually a nicer solution because bluetooth can be much lower power doing this with wi-fi in the meter my main concern with this is just how to power the thing like if i if i put something like a a tiny pico in there tiny pico can use a very very small amount of power when it goes into sleep mode xeon specifically designed it to be as low power as possible but you just can't get around the power requirements of communicating on wi-fi the reality is it just takes a bunch of power it takes hundreds of milliamps in surge on startup while it does its calibration of its uh its radios so maybe i still want to keep going with this project because it's kind of interesting but maybe the more sensible thing to do would be to get something like a a ut61e plus with bluetooth and then get a bluetooth yeah makeup okay esp32 already has bluetooth so you could probably do this with nothing but something like a tiny picot plugged into a power supply and some code loaded on it and that's it but um anyway where's the fun in that well actually quite a lot of fun but uh all right so it looks it looks like the uc61e is still available but it i don't know for how long this is actually a pretty old multimeter i've had mine for many years and when the design came out it went 2007 yeah when we um last week when we looked at the data sheet the schematic for this i think it was dated 2007 so it's been around for a while [Music] oh look at this it's talking about the data stuff here on the 61e with the rs232 interface pmin pmax so it's got peak maximum in and that's the adapter oh look there oh cool check this out this is the transistor adapter so last week when we were looking at the schematic there was the little section in the schematic for the transistor tester with the contacts where you can grab a transistor and shove its pins on and then measure its characteristics and this is what it looks like it plugs into ports on the front of the meter and then it exposes these little contacts and it looks like it's got pins in like holes in here where pins can be stuck in and you can measure it says rc in the middle there it's probably very hard for you to read this is um it's just molded into the plastic but yeah stick that into the meter and then you can do transistor testing anyway what are we doing what are we doing today folks what are we doing today brain same thing as always taking over the world oh james said i've got that transistor adapter hmm cool yeah the calling feast did i just hear john say he was going for the off the shelf option there goes the next three weeks of streaming content yeah yes no i'm i'm kind of interested in this i like the idea of hacking around on this multimeter and aaron said i assume the plus model has a bigger battery to accommodate the extra draw yeah okay [Music] oh leland said um i'm talking about it in general i wouldn't touch uni t with a hundred foot pole that's interesting so have you had i've missed a whole lot of um uh of chat here so i don't know what leland is following up uh oh james said i bought the ut61a a month or two ago oh yeah so tim said the ut-139c is the new budget dmm albeit not as precise yes so uh okay i was gonna talk about that as well because that one was also brought up on twitter i can't remember who my memory for assigning correct credit to people is very poor so um where are we shipping delay all right so it seems leland doesn't like the the uni t meters but i'm not sure specifically why so leland if you've had bad experiences with um with uni t or whatever i would like to hear about it because um uh negative reviews are just as useful as positive ones probably more so um oh joe said i've got the ut61edc clamp amp meter yeah i've got a few uni-t meters i've got like right here plugged into my bench i've got this i've got the usb power meter so when i'm running stuff on the bench here i plug it in through the power meter and i can see how much power it's drawing i've got there i've got a couple of the ut61es and i've got another one i can't remember which model it is what part number but it's i think it's this the one that is specifically for capacitance testing and it's got a much better range like it's got it measures down to much smaller capacitance than the ut61e yeah so ut139c one thing i'm interested in with the 139c is what chip is in it because when i started digging into this after i saw this on twitter last night i um i did a quick search on the ut139c and um and tear downs and things the only the one tear down that i looked at was very short it was just opening the um the cover and saying you know this is the circuit board inside it it really didn't tell us very much about what's going on uh ut61e usually 139c schematic let's see what we can find anyway from what little i came across it looked like maybe it's got an stm32 in there instead of a specialized oh what is let's um let's see if we can find out a bit from here uh yes yes yes yes yes all right what i'm interested in is what chip is actually driving this is it a um i assume that because the specs are different it won't be the same chip as the ut61e interfaces it doesn't have any interfaces oh that's disappointing if it doesn't have any exposed that probably means that whatever chip is in it doesn't have support for it so let's see if we can find where it is i think this is the photo we want oh here we go here's dmm chip dtm 0 this could be interesting let's see if we can find the data sheet for this data sheet translated nice uh so if this doesn't have um [Music] a data interface on the chip itself then basically there's nothing you can do not without crazy amounts of work that are way above my pay grade so uh i mean this is a this is squirrel chasing when we're meant to be hacking on the ut61e but i'm curious about this because the 139c seems to be a really good viable replacement for the 61e it's kind of equivalent specs and it's low priced and i think it's a more it's a newer design so it's more likely to uh to be around for a while oh it does have auto power off and remember last time we discovered that the ut61e does actually have auto power off but it's disabled because they um they just assert that pin continuously to make it think that there's a pc attached even when there isn't do we have oh there's a pin out we could look around all the pins but that's probably going to take a while let's just look through the descriptions what have we got uh data what oh oh no rc clock lvd pwm output frequency output data input out oh no it's just a description okay it's going to say that about all of them spi communications ooh eu art port rc mode test eu output tx whether it actually outputs any data is another thing so it does have a tx pin and that so [Music] i don't have a 139c otherwise i would be pulling it apart and probing that pin maybe it's worth ordering a 139c just to see what it can do hmm all right let's find our data okay data data maybe i should be searching for tx there won't be so many eprom data reserve power on okay min max data recording oh let's loop back to the start all right let's look for it tx oh come on is that the only place in the data sheet that it mentions tx it's just right there pin 20. all right what about pt 1.4 is there any other reference to that in the data sheet no hang on how can that have no references i just copied that from right here it's there or maybe because it i didn't have the trailer no surely the trailing it's saying that that text that i just copied from the data sheet does not exist in the data sheet pt one point four okay only one all right so we're really in the dark here we could read through more of the data sheet oh no that's the end of the data sheet that's it that's um that's rather sad it's only 10 pages long and what i was really hoping to see oh hang on you are you are you are here we go uart format uh so bit 76543 to zero low voltage power off delay and here's phony c ui uses 14 bytes you what uses 15 bytes okay so it looks like there is some possibility to get data out of the ut139c however i don't have one so all right we'll just sort of park that in the back of our minds for a future reference maybe it'll be something that can be done but all of this so who was it earlier said yeah back there someone said that i'm did i say that i was gonna solve the problem by just buying something that would actually be the sensible thing to do uh you know if you do the if you do the calculation okay let's just use round numbers if your time if you're billing say you're doing contract work and you're billing a hundred dollars an hour and you could buy a 100 meter with bluetooth in it that you'd plug in and it would just work versus spending two hours or 10 hours retrofitting comms into an existing meter that you already have you're better off just going and buying the meter spend 100 and put your hours and hours of time into something that's a bit more useful but that's not really why we're here is it we're here to do interesting things and learn how stuff works so part of the reason that i'm uh yeah aaron wants to know hey are we technically on topic or is this a squirrel um um this is the topic is a squirrel and this is the squirrel's cousin i think so oh yeah the ut139c it's related to the topic it's related to the squirrel in some way so the reason that i'm doing this is just that i like to understand how things work and that's i suppose what this whole youtube channel is about it's about figuring things out and making them for yourself it's not necessarily the best use of time if you just look at it from a purely economic point of view but this is how you learn digging things out and pulling them apart alright so i'll just remove my desktop for a moment because i'm going to open some things and i'll see what i had um just looking for some see what i stored from last week projects ut here we go i have a folder oh there's no resources all right why is there an enclosure folder there's nothing in it i don't know images okay so i had some stuff here i started putting together like just a uh a skeleton of a project let's make a new folder resources what i really should have done last time was save the raw ut 61e i can't even remember the name of the chip that's in it now gt61e schematic so this is a different squirrel but something that is worth talking about sometime is how you set up your projects ut61a how you store all of the stuff related to it [Music] for esp es519 i think that is the yeah that's the chip that goes on it so data sheet i think this is the data sheet for the the multimeter chip that drives it all yes it is okay so what i'm going to do is save save this come on no you're not copy come on download okay so the other thing i want is the schematic for the ut61a itself is this it is this a pdf it's just an image still it's a pretty good quality image so let's save that yeah that'll do stick it there so i want that yes i want to move it don't ask me to confirm i did it because i wanted to do it now where is downloads downloads come on datasheet a3 where is the datasheet date that one okay and here is the datasheet all right so starting to collect some resources for this thing anyway so what i've got here is my project skeleton and notes what did i put in notes is it blank i don't remember let's find out oh no okay so i i was taking notes so as i was starting to dig into this i made a notes file and uh stuck in some just put in urls and things oh look there's the data sheet in fact i think this is where we just ended up circuit diagram that's the one we've just got converting serial cable so i stored some notes and now we've got these things saved here all right so we're kind of at the starting line almost um oh james offered said i had to run off for a second uh did you want me to drop the unit transistor adapter around next time i'm near your place hmm i wonder if it would be useful i've uh if you don't have it if you don't have a use for it james i would be interested to look at it from memory there's not much in it let's open up this um this schematic and where are we transition here it is yeah what's actually inside it is just these two resistors these two 180k resistors and a bunch of contacts so what this doesn't show us is the arrangement of those contacts and as we saw when i had the picture of it up before it's got multiple contacts in different locations with different arrangements obviously because pinouts are different for npn and pnp so what we've got here is a shared collector and a shared no there are two different b links here so the base either comes off the negative or the positive depending on whether you're checking an npn or a pnp transistor and the emitter always comes to the voltage input and here we've got the common connection so the transistor tester just arranges these four pins or a subset of them in different physical arrangements to suit the different types of transistor that you would want to plug in but electrically this is all that's inside it it's not much there at all uh yeah so hmm oh looks like something odd was going on there and johnny has taken care of it thanks johnny um [Music] so now okay so james the question was whether i wanted james to drop off the transistor tester and thanks for the offer but i'll say no for now i don't have a be a real use for it the only reason for grabbing it from you would be to you know just to look at it and test it see how it works oh james said i'll upload a high-res image to discord awesome cool well thank you that will hopefully show us where all the connections and things are on that adapter anyway now so back to the squirrel at hand and the squirrel that we are chasing today is data from this nice little fellow here the es51922 and specifically the data that appears on the base of q4 and then modulates this infrared led now where we left it last time i still have the stuff sitting here on my bench getting in my way was we pulled apart the the little adapter cut the sides off it and now we have the infrared photo transistor that feeds into this little circuit with an rs232 interface on it and i botched up this connection and we could see packets of data but it was kind of dirty data what i'm interested to do is okay there are a couple of different approaches we could take with this whole thing the non-intrusive way of doing it is the path i was going down with this and that is making a device that hangs on the back of the multimeter it connects into the optical port and we could put an esp32 or something in it and we just read the data off it and then push it to mqtt or wherever we want the other way of doing it is to put a device inside the multimeter and tap directly into the data line so in one of these cases in the first case what we are doing effectively is looking at the data that comes out in this area here after we've received it and then we can pull the data out in the second case if we build the device inside we would look at what's going on on the base of q4 here oh there's a 10k resistor doesn't really matter we could come either side of that resistor probably so what we could do is put a digital input into a um a processor and find where this track is and uh and do that now there are advantages to both i ultimately from a usability point of view i really like the idea of having everything integrated into the case and having it so that it is just like a ut61a multimeter except that now it has wi-fi that would be cool but there are some issues with that the biggest issue is power as i've mentioned before how are we going to power the device and during testing it also leads to isolation issues because if we've got if we've got a device like a d1 mini or a tiny pico or whatever plugged into usb and then that is patched into the multimeter now luckily the multimeter runs off battery so it has isolation already but you've got to be careful with this sort of thing because you can end up with issues like ground loops or ground offsets not yeah ground locks aren't really a problem it's ground offsets that are the problem because okay imagine this scenario we have a computer which we're using for development plugged by usb into so we've got usb computer usb into the d1 mini d1 mini is connected into the back of the multimeter and they need a common ground in order to be able to do their serial comms the multimeter is powered from a battery and then while testing it you use the multimeter and you plug it into some kind of a voltage source so that you can get a value off it and then you can see what's going on now i haven't actually looked at how this works but depending on the isolation in the multimeter you might end up with a situation where you smoke the multimeter the d1 mini or your computer because of a difference in the ground reference voltage now multimeters generally run off a battery in order to totally avoid that problem it means that whatever you plug it into it's just referenced off you know the the load that you're measuring and you avoid that whole problem so the idea of of hacking around on the inside of the multimeter is not that great for that reason it would be nice to whatever we come up with in this project make something that you can take a regular unmodified ut61 where is it uh i don't even know where i put it the one that i was hacking around with the other day we're gonna need it i need to find it what did i do oh everything's a mess right now um that would be funny if i if i can't even find it oh there it is okay i was looking for it to be sitting out on a bench somewhere but i'd actually put it back in the place where it normally goes like it's actual legitimate spot so what would be really nice is have a totally stock ut61e pop the little thing off the back have another little device of some kind that we come we're going to come up with that hook clips into this and that device could have its own power supply so it might have um it could have a battery in it and power management and a usb connection so that you can plug it in for recharging and its own separate power switch so it'd be a totally independent circuit that is not electrically coupled at all to the multimeter that we'd be hacking around on it just reads the data coming out of the port on the back of it so i think that is probably the direction that i would like to go with all of this hmm okay hmm um uh okay so joe anon said the rs232 is for the output input is used for the display if i recall correctly okay yeah so there was a mention of the display connection last week as well um so there okay tyler has posted a bunch of questions and um this is not necessarily the the time or place to start addressing all of these questions but i just noticed that there are a lot that have come up in the chat and it could be that tyler has a serious problem with um uh with someone messing around with them so i this is not really the time for me i don't know if i can help you tyler um maybe if someone in the chat wants to talk to tyler and find out what's going on go for it but uh i'm not really in a position to do it right now yeah and as aaron said this is not the audience not the audience here to assist yeah [Music] oh peter made it cool so yeah sorry tyler i don't know if you're what's going on with you but i i can't help right now unfortunately i'm going to try to stick with this project all right so uh yeah so where i'm going with this it's kind of looping around to my original concept which is a box that goes onto the back so what we could do is put is we could use something like an esp32 baseboard which has its own power management built in and there are some good candidates for that of course and then just have it in there with a little lipo so that it can be recharged and maybe a power switch on top so you could leave it hanging on the back of the multimeter and then when you want wi-fi you flick the switch and it powers up and then it starts broadcasting the data that comes out of the port but in the meantime what i'm interested to do is it's just probe around in the data so back to this thing here what i'm curious to know is what is happening on this data line so maybe that's the logical next place to to take all of this okay step one remove battery and oh got an assembly overlay there from yesterday i was um assembling a batch of uh io relay 8 modules because i've had a few people say they want them and they're out of stock at the moment they're you know the real thing about assembling those those particular modules okay where are they i'll show you one i've got this little tray of them so this is a this is a tray of the io relay 8 modules that i was just assembling yesterday and i'll keep my fingers off them because these have already been through the ultrasonic bath and they should be absolutely perfectly pristine clean and span i hope and anyway i ran these through the pick and place machine yesterday assembled a little batch of them and the funny thing was i just set the machine up and i was right about to hit go on the pick and place job when alberto turned up so alberto is a mechanical engineer at the the water cannon company for that that thing and he turned up to drop off some stuff for me so i ran the pick and place job while he was here and he got to see the machine running which was cool anyway so i um i use the machine to do all of the part placement and then so that's fine i can run the machine all day what really sucks about this it's these screw terminals i hate putting these things in like i've made up assembly jigs and things so that things like you know all of this can be held in place the little idc connectors soldering those on isn't too bad i can just sit there and listen to a podcast and solder those on but what annoys me about these is assembling them the because they come in short bits and yes this is a squirrel i know you came here for squirrels didn't you if there weren't squirrels then this just wouldn't be super house so anyway they come like this and they have to be jammed together so you've got to align the little duval lucky slots on the side and sort of wriggle it to get it straight and push it down and then you grab the next one and you push it down and then you grab the next one and you push it down and after a while you end up with blisters on your fingers so all right so i've done four there which is half the size of one of these and then they end up slightly stepped like you can see there's a little bit of a step between them and getting them to really push down is actually surprisingly hard you've really got to get the angle right and push hard to make that align so that it is all straight and it's very frustrating so i sat here for ages last night with these just going and then soldering them on i hate doing that that's the worst part of the assembly all right i think the worst parts of assembly are things like little screw terminals and the other thing the other bad thing is wiring harnesses doing and connectors like just connectors in general suck they're always really awkward to do things like crimp connectors i hate them so anything that involves wiring i just dislike it i'd rather design a circuit board than to hand wire something so oh that's right now this is kind of a squirrel that thing over there the light switch controller i was going to talk about that maybe later all right let's let's defer that squirrel i do want to talk about that because that has been that has taken up a lot of time this week there have been some major changes to that but for now let's have a look at this that one that one should get in there this screw is in a very awkward position it's right next to the 10 amp fuse so it's a little bit hard to get to and oh maybe i can do it from this side i know that where's the transistor i think the transistor might be on the back i can't remember let's get this pcb out and then we will find out and then maybe we can see data coming off the chip so even though ultimately i'm kind of leaning towards doing this as an external device rather than you know there is actually room in here we could there is space in around this area for example there's a bit of volume inside the enclosure we'll just stick a tiny picot in there and fit easily you put half a dozen tiny picots in there but i'm still leaning towards making an external device every time i do this i worry that i'm going to screw up and not be able to get the the lcd aligned again properly because it's got these little um you know z-axis conductive things that take it connects to the contacts oh you can't see it there it is so there are there's a row of contacts across the top of the pcb and that connects to that little rubber strip that goes along there which is actually a whole lot of parallel conductors running through so it passes through to the lcd every time i take this off i am afraid that i'm not going to be able to get it back together again okay so there is the multimeter chip and i suspect that this up here in the corner is the transistor that is driving the oh there's an sd sdo is sdo the the one we need if there is a test point on there that does it that would be fantastic or is sdo something else no sdo is what we want ah that is so nice look at this coming down here data pin sdo is serial data out and let's chuck it under the microscope because what there is hang on brightness down cut the glare look at that sdo that little test pad right there and q4 so this transistor up in the corner here is the one that drives the data output so that test pad sdo is exactly where we we want to be picking up data nice now i've just got to find a zero volt reference somewhere which should be handy there should be let's see what's going on with the circuit there's one on the other side of the uh sorry i'm just looking at the schematic there's one on the other side of the infrared diode so let's find a ground point it is positive goes to there freaking what's that com1 com i think might be common which might be if we're lucky com is common which is ground kind of well terminology i know people will be saying but ground it's not actually ground yes i know it's not actually ground but i'm lazy and i use that terminology all right i can find out sorry you can't really see what's going on right now but i'm just going to try to buzz this out and see if that is oh maybe it's not that's interesting com i would have thought that com oh it says com1 all right so the point of all of this hang on i'm looking at the track oh it's over that's over there sorry i know this is not very uh not very riveting viewing no that com1 is not common as in zero volts that is something different now we've got so d2 over there and presumably those big screw terminals are ground as well or maybe a shield or something it could be it may not actually be yeah it looks like that might be a shield it's not the same as negative i'm kind of rambling here i'm not making a whole lot of sense uh let's yeah so negative is there but not there all right well that's interesting okay so this is kind of worth mentioning now what you can see here and i haven't looked at the chat for a while so i apologize if people are telling me things all right so what you can see here this big hole is where one of the screws goes through to secure the pcb inside the enclosure and you can see that it is specifically connected to these other things here and if we come across here to the other side you can see that that is the other screwed connection and it's connected to this big track so what i think is going on is that these are connected to something like a shield connection it's not zero volts or ground so if we see this track that comes across here the one that i'm pointing at it goes under the com1 label loops around it comes down and it comes to this via just there that is actually zero volts that track right there and it is not connected to this so i think this is like a shield it's probably connected to zero volts through a ferrite or something is my guess but it's not just hard connected so whatever the shield is is not the zero volts of the logic of the meter so there's isolation there and it's probably connected through like on the front end of the multimeter chip there is probably some isolation that allows it to um to not pass noise through so um this would where are we inputs inputs so the inputs are connected through here um i'm not going to trace this through now it's not directly related but anyway i just thought it was kind of interesting that what looks there at first glance to be like a zero volt connection is not actually connected to logic zero volts in the meter so which is something to be careful of anyway the um the cathode side of the led now this is the infrared led right here the cathode side on this side you can see the track comes down around here there's a little bear i'll try to be a bit more clear with my pointer there's a little bare piece there exposed copper the track comes up across here comes along the top of the board this is the one i was just talking about before so this is the negative side of the led and it comes down through to here and it comes to that via now if um if if i connect so i've got my other ut61e in continuity d mode and i stick one probe on the negative battery terminal and i come down to the the cathode side there of the led you can hear that that is zero volts and tracing it along here to where that little via is that is also zero volts so what we can do is anyway this has been a very long long winded thing about just finding a ground connection uh so [Music] what i'm thinking about here is how to uh how to measure this okay we can put this back in the enclosure sorry that beeping your hearing is my my right goal starting up so what i'm going to do let's put all this back in the enclosure now that we've found that we can get all of the signals that we need on or have we what did i find where where where where was content seo yes yes that's right so we've now found that we can get all the signals we need on the back of the pcb we don't actually need this out of the enclosure i can put this back in the enclosure and then i can stop stressing about the connections to the lcd and they can all be kept in place and do what they need to do so i'll try to get this back in here one thing i one thing that is they slightly skimped on with the 61e are these connections so these banana jacks that the lead test leads plug into as you can see they are just a flat piece of steel that has been folded to like the tab coming off it and rolled so it's got a rolled section there with a split in it and it's just a bit dinky it's a bit on the cheap side it's not like a top quality banana jack so then when you're putting the meter back together you've got to get all these aligned with the plastic enclosure to get it back in so i'm actually going to be quite happy to not have to take the back off this meter again i'll not have to take the pcb out of the meter and now you can see that because they haven't aligned properly it's holding this up and i don't want to damage these slightly flimsy banana jacks oh come on okay i think we've got it all aligned um [Music] is it gonna clip in oh it really felt and sounded like it was breaking then but i don't think it did all right so let's test this um which way uh negative that way all right so i'm just gonna hold the battery on there turn it back on and see if we have a meter that still works it beeps [Music] we've got no display uh you can see the backlight comes on but we've got no display this is this is not exactly what i was worrying about well if i've broken the display on this this meter may now need a data connection just to become usable all right i'm going to take this back out and see what is going on with this with this lcd so there's that rubber z-strip stuff there maybe it just wasn't quite aligned properly it's got these little alignment pins just here that go through the pcb so i'll pop those into place push down on it click the bottom in place oh this would really suck if i've just killed my multimeter and you can see there the gap between the lcd and that little z-strip rubber thing and the pcb so when that is clamped together that is supposed to make electrical contact well maybe i just wasn't pushing down on it it could be as simple as that maybe it'll work once i screw it back together okay might have been a false alarm [Music] put that back in place rather little legs coming through i can't see oh yes they are okay so the little pins from the back of the lcd are coming through now all right so i'll clip this back and that tells me that it is aligned snap that back into place and we probably still have let's see if we get an lcd coming up now we don't even get a beep oh come on was i connecting the battery backwards yeah so we've got no functioning led but i'm going to screw this in and hopefully the lcd is going to work again otherwise i am going to be a very sad squirrel chaser although for these purposes for our purposes of making an internet connected multimeter it's probably not a huge deal although doing things like making sure that the data we are seeing is what we expect would be rather difficult negative that way all right come on you better work yes i saw it for a brief moment yes the lcd is working that's a relief all right so i needed those screws in there to push down onto that little z contact strip and then it worked again i'm glad i didn't just kill a multimeter those little rubber strips always strike me as being a potential same like damage point you see them in lcd like also lcd wrist watches and calculators and things as well and i've never liked them they always seem like black magic to me all right so now we're back to having a working multimeter probably yes and we now know that we can take ground from either the negative side of the led or from the battery terminal and we've got sdo so serial data out right there and that is the data pin coming out of the chip so let's uh take the soldering iron to my multimeter it doesn't make me nervous at all not in the slightest because what i want to do is just connect on a little patch lead [Music] there i am what else i've really lost the plot what am i doing all right i just want to have somewhere that i can connect a [Music] uh a probe onto this so i'm just gonna turn on my little extraction fan while i solder this which is going to make a bit of noise but that's what you have to put up with in order to not be breathing the nasty fumes right so let's just get some how can i get the easiest angle on this and where is it that you can see it okay right about there which way to focus about there okay just gonna solder a little wire onto the onto that test point on the pcb so i'll just tin the wire first right in the test point first now what i'd like to be able to do is bring this wire out if i bring both the wires out i'd like to bring out a ground wire and a data line and put the back cover back on and if i can bring it out through there what can i use oh i know what i can do i can pass it through oh i can pass it through the hole in the back here we've got the two data ports the optical ports what i was just thinking of doing was popping the cover out but no it's been heat welded in place and i don't want to i'm trying to avoid breaking stuff basically there's a spot in the case i'm just looking for holes in the case that i can pass some wires out through and still be able to have the case closed because that way i can have the battery in it and it's just much more robust now i think yeah i think i am going to take the back cover out of this so this is what i'm talking about there is this little clear cover here and this goes through and covers the two optical ports one's the transmit port one's a receive port and the receive port is not actually it's not used for anything there's nothing inside the multimeter you can see the transmit port here with the infrared led this is where the receive port would be and there's nothing there so if i take this out can i get this little heat weld thing off it's kind of it's very flush i can't even get the cutters onto it properly just trying to remove that so that i can pop this cover out can i cut it a bit i'm trying to do it in the least invasive way possible um doesn't want to come out come on maybe that was it there we go yes i think that might have done it yep all right so we got that out that means that if i connect a couple of wires to the inside of the multimeter we'll be able to pass them out through that port and put the cover back on so i'm going to use unfortunately i don't have any black wire wrap wire here so i'm going to use blue for the zero volt connection and yellow for the data connection um [Music] here we have i'm just going to connect onto the led and solder this in here all right and then the data connection i'm just going to solder on to the test point on the pcb which is right there sorry if i'm sticking my head in the way no not too bad and then we can feed those through the case like that there you go and close the case up so now we have connections to the zero volt reference inside the multimeter and the data pin so this is now directly connected to the the serial data output of the multimeter chip and uh let's try which way does this go plus minus that way so i'll put the battery back in the meter come on oh turn it off screw it closed i'm not going to bother with the other two screws just yet and let's see if we can see any useful stuff coming out of this port now this is going to take a little bit of jiggery pokery to set up and um initially you're not going to be able to see anything from your vantage point stuck in the camera in there now uh what do we have here i will just get myself all arranged here and then hopefully i will be able to give you a view of what's going on and there we go [Music] just going to change the vertical scale a bit and then i will show you what we're looking at and it does indeed seem that we have a packet of data coming out there now run all right what do i need okay i need a tripod i need my phone i need video going into obs so you can see the oscilloscope um all right i am not very organized not very organized at all uh okay so where are we where are we okay sorry i am i have temporarily discombobulated all right we're heading towards the end of our time together today but uh but we are going to see some data coming out of this uh oh firefight said there are quite a few references online to adding local power and cost bluetooth modules to the ut61e one in particular jake's blog covers installation there's also a software toolkit yes there's um uh there are many yeah there are many ut61e hacks um i don't know if i've seen that one that you referenced jake's blog in particular that is worth checking out in fact before i go any further with this while i'm still thinking about that that's um let's switch back to desktop and close this so notes notes stock markdown this is where i've been sticking some of the things that i've found so let's have a look jake ut61e bluetooth let's see if this finds looks like i might do bluetooth mod with an hm11 coolio now over bluetooth hm11 hm10 which i don't think i have an hm11 but i've got a few other ble modules here so i'm gonna make a note of that one and stick this in here all right thank you for thanks firefight firefight for that tip i haven't actually seen that one before so yeah i've been looking around and i've seen a bunch of different hacks for the ut61a but that's specifically that specific one oh look at this cool so they've taken it off that same point sdo so power connection [Music] yeah kind of like this oh and he's added a switch okay what's there is a convenient pad label sdo which is a text line yep and what is the switch for disable bluetooth transmission to increase battery life yep so multimeter draws two milliamps when uh not in use okay so what jake did was use the you make up a little thing here which clips into this back cover in fact i think that is the back cover that's the the little bit of plastic that comes it's just a a thing that fills the hole and then put a switch inside it so that you can pop it open and turn the switch on or off in order to enable or disable the bluetooth so that's kind of cool all right that is definitely worth looking at um so it says the hm11 draws about 9 milliamps from the 3.3 volt rail and yeah okay cool thanks firefight um now what was i doing that's right i was getting things set up so you could see this data packet and just to make it easy i'm gonna grab this tripod and stick my phone on it now i have no idea this is going to work because i was using droid cam on this and i haven't actually done this since switching to this computer so let's see if we can get a wi-fi ip252 droid cam okay hopefully this will work because i think what happened the way this works is the uh is that obs connects to the phone not the other way around so if i go where are we portable is it gonna work yes it works awesome okay now i just got to get a little bit of zoomage can i zoom from here i can oh okay so what we can see here is the scope which is currently looking and i ran a capture on it so i'm just going to put it back into run mode again so the it's now just running and you can see flickering across the screen occasionally it's getting these bursts of activity which are the um the data packets coming through so there should be two per second so if i stick this into single shot mode and let it capture you can see that it has just captured um a chunk of data in fact i'll um i'll just run it again so it makes it a bit easier to see when it's when the time base is set like that so i'll just put it into single mode zoom in and here we have the data coming out of the port so as you can see we are getting data and that will be the 7-bit serial data that we were talking about last time so in the data sheet it had the specs for for what that should look like but that is the data packet of a reading effectively reading zero volts because there's nothing connected to it but that is the data packet that just came out of the meter a moment ago captured on the scope so we do have some data which is nice okay now in that view you can see yeah you can see the um the meter just sitting there on the bench and very thin in fact i don't think you can even see them the on that camera there are the very thin wires coming it looks magic it's like there's nothing connected to it but there is there are very thin wires coming out of it going to the at the oscilloscope probes all right okay if this was a drinking game what if we had a drinking game on this what would the drink thing be uh if it was squirrels we would end up i was gonna say very drunk but i'm only drinking pepsi i'm never going to get drunk on that hang on who said cool yeah did i say coolio i didn't even realize that i said it ah kraken release the kraken uh so what's the spring oh aaron said oh hang on okay oh there are some interesting little questions here in the chat so aaron said is it safety to stop you using it whilst open as in disabled screen no uh so [Music] yeah so what aaron is talking about there is that spring that is on the inside of the multimeter sticking up and no that spring is to make contact with the shield that is in the back part of the case and to provide more shielding around the internals of the multimeter now we are at 11 50 a.m nearly at the end of two hours and once again we've made effectively zero progress pancake thank you for the five kanger bucks um pancake said i left something for you in slack chat i am so slack at keeping track of slack yeah i'm gonna jump across now may not be the time to be looking at this but pancake says that he has left me something and um so andrew who is pancake legend a low profile hardware design for the xero stick ooh okay that is something that i that is a squirrel that i am very very tempted to chase oh that is that a render that's beautiful okay i'm gonna drag this across this is a squirrel this is this is not what um not the subject that we're on today but andrew has done some amazing work here zero pad so it is a low profile hardware design for the zero stick light yes light controller update that is what i'm wanting to get to before you know the day is over i will get to that this is a brief intermission on the way to the light switch before i wrap it up so this is a design to measure x and y axis force in a very low profile design now for context last week i showed this and a number of times i have shown this so this is the zero stick there are two load cells mounted at 90 degrees to each other so it's a joystick that doesn't move and basically just by applying force to it and changing how hard you push it's like moving a joystick a different amount and this is for use by people who have reduced range of motion for example someone who has to shed muscular dystrophy can use this and they don't need to move their fingers in order to move the joystick all they do is apply more force so it's a zero deflection joystick and this one is currently set up to emulate a mouse so i can plug this into my computer and drive the computer and it's and it works really nicely oh and this thing which i went over to chris's place yesterday and did a brief test this is a thing to give an i squared c interface to a wheelchair controller and it didn't work but we'll be debugging that this week anyway the point of all of that is that zero stick project uh relates to this so andrew has been experimenting with different designs and look at this this is beautiful now that looks like it's actually printed this looks real i think this top one that's a render this is real very very cool so those parts on here these are 3d printed they're not really load cells but what it looks like is andrew has gone ahead and made a an alternate arrangement for a an input device like so an assistive technology input device and instead of having the two load cells mounted vertically they are mounted horizontally and then there is a mechanism that translates the force applied to the center point to the load cells in the x and y axes so and the load cells can read positive and negative pressure so they can read deflections in both directions um i this is really nice andrew i'm impressed very very nice work so we've got to catch up sometime meet up in person because i haven't seen you for ages and i've got some of these load cells so what we can do is combine the load cells that i have with the 3d print structure that you've got and yeah aaron said nice engineering solution uh pancake legend yeah so pancake does amazing design work really really pretty and functional and nice so let's zoom in on this render and admire it okay now uh thanks andrew i really appreciate seeing that design that's really cool um now uh yes so pancake you were meant to be coming over here for a barbecue and i never got around to arranging the barbecue i'm sorry about that so what am i looking at eagle eagle and i'm getting into eagle because i'm going to show you some updates to the light switch project now before i get into this because this is going to be the last thing i talk about today i'm okay quick wrap wrap up time on this ut61e where are we at with this what is going on i really hate it when people say what is up youtube but i just had the urge to say it right then so okay we've we can see there is data coming off this we can see the packets on the scope and i think maybe the next thing to do is to connect this data pin so this one is sdo to an esp32 and i'm just going to turn off my scope because the the fan is annoyingly loud and turn off the fume thing and turn off the soldering iron is off good um and basically just connect this to the serial serial input on an esp32 and set it up so that it has got the um the correct thing in fact i did a little bit of messing around with this i shouldn't have closed that window now i've got to get back into it super house projects i'm going to pull this up and show you what i did that we can continue with same bat time same bat place next week and where are we firmware okay uh i'm just going to open this off as in off stream before i show it to you because when you open arduino ide it opens all the previously opened well whatever sketches you had open previously it opens and it's it's quite likely that i have a client project stuff on there which i shouldn't be disclosing on a live stream so i'm opening aaron said we soldered two hours two wires in two hours so eta is next year sometime no i think next year sometime is being optimistic aaron at this rate yeah we're going to be running into the the y2036 bug before we get this project done zero stick firmware okay yes i did have some customer stuff open which you uh that's which control i'm qtt yeah zero stick firmware that's all right okay so back to my desktop here we go what i've done in preparation i haven't actually run either of those things i've just created them what i've got are two projects one is ut61a serial reflector let's have a look in that to start with and what this does it's just a slightly modified version of the example serial reflector that you know the demo that's in the arduino ide and what it does is open a regular serial port which is the hardware serial port and then it opens serial one which is the second hardware uart on the esp32 and it opens it at 19200 and the baud rate oh not the baud rate the um the encoding is a little bit unusual instead of just being so typically when you open a serial port it will be what's known as 8n1 so that's 8 bits so 8 data bits um no parity which is the n and uh one stock bit so this one is a little bit strange instead of being eight n one it is 7 0 1 so it's 7 data bits and then it's odd parity not even parity and one stop bit so anyway this will open a serial connection at 19 200 bits a second seven data bits odd parity one stop which according to the specifications like the data sheet for that multimeter chip that is what we need and then all it does is if data is available on serial one it just writes that value what it whatever it reads on port one it just writes out to the other serial port anyway what this will do is turn an esp32 into a bridge takes data in one serial port at one board rate and with one type of encoding and it pumps out the other serial port so that we can see it so with this sketch loaded onto an esp32 and then the connection to the multimeter we should be able to connect usb and just see the data coming out that's the idea totally untested what have i got this setup for at the moment uh seed we know zhao because i was working on the xero stick but if i go to uh esp32 dev module i think i got as far as basically as making sure these things compile the things i'm about to show you so come on you can do it it takes a while to change modes from one processor to another okay here we go so now yeah anyway none of that matters so this will come it should compile it's not a whole lot there to not compile um and the other one so that is a serial reflector so the very first thing i want to do next thing i want to do and this is what i was expecting to be doing today is just taking that data that comes out of the multimeter sticking it into an esp32 running this program and watching the data coming out of it and then we can do decoding or whatever we want to do so then assuming that works that's this is like the minimum oh come on you're still compiling uh yeah it takes a while um so this is like the minimum thing it's just taking the data out of that sdo hurry up i'm waiting for you to finish anyway okay and the other one is this one so ut61e wi-fi this sketch this is actually a copy of the air quality sensor firmware and i spent a while just in fact it even says particular matter sensor firmware still says it so what i did was i just duplicated that project and then ripped the guts out of it so i need to um because i just wanted the basics like i wanted something that will connect to wi-fi and connect to an mqtt broker and publish some stuff so my plan is to mash it together so whatever is going on here i mean it's very short now because i've ripped out all of the stuff related to the air quality sensor i'm not even sure if this compiles right now but this is basically going to be a starting point so what we want it to be able to do where are we in in the loop all right so right now what this is doing is every time around the loop it just generates a random number print it to the serial port and publishes it to mqtt waits three seconds and then does it again in fact i need to get rid of that delay that's bad that'll um that'll stop it from that'll stop mqtt from working properly so um what the plan is to do is in here just take the um the usb serial reflector thing so open the serial port from the multimeter read it maybe do some decoding on it so we can figure out what mode the multimeter is in all that sort of stuff and then publish the data into mqtt so anyway i got as far as you know mocking up or skeletoning up these projects so that we can get on to playing with those in the future no now eee goal projects projects i2c rj45 okay now i'm going to start with all right i'm going to go back to the previous one so you've got context this is the one this is the where is it version version 2.1 this is the version 2.1 board that that you would have seen in the past and this one is [Music] i thought there was one right here somewhere um i had it all out yesterday oh it's back in the box it's too obvious that's what's going on all right i've got i have two incomplete ones here and i'll bring some other stuff over to show you as well so so this which one is this this is version 1.0 so this is the first one i did so it's the rj40 24 port rj45 breakout with i squared c and you can see it doesn't have any of the mcp2307s on here because i ran out of them and i pulled them off here to put them onto another board and then you can see this one is the version 2.0 board and it's got the mcp23017s on it but it doesn't have the rj45 sockets or the passthrough or pass through down here or anything else so and then there was another one that i did so this the version 2.0 i actually just posted one to some the boy a couple of days ago so there is a complete one of these going to to summon a boy and um the main the difference between these let's stick it over here then you'll be able to see it a bit better go go gadget overhead camera all right and i'll bring up my own preview so i can see all right so this is the version 1.0 board this was the first one i did and you can see that on the end here it's got a six-way connector which has got i squared c and power and int so that's the interrupt output coming from the mcps and vn there's no reset connection on there and that's the only connection to it and this was before i really thought about standardizing on i squared c connection so what you can see on this is there instead of the one by six header it's got a little idc header unpopulated and that is the i squared c breakout header that i've been using on lots of projects now since then because it means i can use idc cables so that's really the major difference between the version 1.0 and the version 2.0 and oh in fact that that printout it looks huge it's just printed on an a4 sheet that is the pin out that i use for i squared see i don't even remember why i've got that there so that was the major thing okay so this brings us kind of up to date this is the version that i've been testing and it's been working i don't have a fully populated version of this right now because the only one that i had that was fully populated i posted to sumnerboy so i don't have that here right now other things of interest so this is the front panel controller thing so this mounts through the front panel and it's got many buttons and the lcd on it and you can see on this one it's got the idc connection so this is two of the i squared c breakouts and they're just connected directly to each other it's a pass through and the reason for that is that you can daisy chain them together so what you do is have you have for example in fact i took a photo of this i have a better way of showing this to you let's see if i can find it and all right let's see if i can find it and pancake said low it's not sao compatible no it's not um one of the i did this before i knew of saos in fact i think i did this before the six pin version of the sao was developed i don't know what the date of this year is it's like it's a couple of years i've had this design and then just not followed through on it are those display boards available dodgy asked not yet but they will be so anyway um wow what am i doing okay what i'm looking for is i took um i took a couple of photos just before i sent off the boards to summon the boy who's going to do some software development on this and do some testing so [Music] and the photos are the best representation of how all of this hooks together here we go all right now uh desktop desktop come on desktop there we go all right now i'll shrink this down a little bit so that you can see all of it now this is not in an enclosure but this is approximately how it would be wired up in an enclosure so we've got the rj45 breakout at the front here and this would be mounted through the front panel down on the bottom right we've got the control panel so it's got the lcd and the buttons and you can see the i squared c connector here there is a cable that goes through and it goes on to this board and then there's another i squared c cable that comes out here and it goes onto this shield now you can see the freetronix box in there there's actually an ether10 inside the box i didn't bother taking it out of the box but that represents where the arduino or the pi or you know whatever little computer you want to use to run this this is where it would go and then there is a shield or a pi hat or whatever that plugs into it and that gives it the i squared c connection and then this pass-through ethernet comes from the front panel then you use a patch cable and you plug it into your board down the back there and this gives you a self-contained little thing so this shield here that you can see this is a hand assembled proto shield it's got a watchdog timer and it's got the i squared c breakout i haven't actually produced the real thing yet but i'm going to fabric i'm going to have boards designed i've already laid it out in eagle to do that properly and i don't know what i'm talking about doesn't even make a whole lot of sense i'm kind of rambling and anyway okay so to get back to this this is what i've had for a couple of years now in fact i think 2017 i might have done the first version of this board which is just ridiculous that i still haven't even released it yet so we've got this one so what i did during the week was i had a good long think and listened to a bunch of feedback about whether this whole end of the pcb should even be there this is where the pass-through is so we've got ethernet coming through the front panel passes through to the back and then it goes through to whatever board you have and there's a power connection here as well but it seems that there are different ideas about what all of this should be connected to so i decided that it would make sense to make a version of this board that didn't have this left end it would only have this portion of it and then that could be coupled with however you want to connect things through here so what i've got is so what i ended up doing was i took the 24 port board and i stripped it down and i'm just going to turn off a back layer here to make it a bit easier to see so what we've got here is a version of that 24-port board but that whole left end is missing it is just the breakouts for the rj45 ports and you can see that i've also doubled up the i squared c breakout here so we've got one at this end and then we've got one at this end and that means that you can connect from either end and you can also daisy chain you can't daisy chain more of these because you run out of i squared c addresses on the mcp23017s but you can put for example you could mount the control panel at the left hand instead of the right hand if you wanted to and just have a nice short cable going to it so i ended up doing a big revision on this and i went through and actually made all of the tracks thicker and improved the routing so it was um yeah it was a really big revision um some of you might be looking at this and thinking why did you bring that up through of the uh take that through a via take it to the other side of the board and then bring it back again there is actually a reason for that that is to prevent splitting the ground plane it's um and you can see the same thing happens down here and down here it's uh that was all to optimize the the pores of the polygons on the top and bottom of the pcb uh so anyway what i did was do this new 24-port board and then and i previously had eight port and 16 port versions as well but i because i had put a lot of work into optimizing all of this routing what i ended up doing was then scrapping the existing 8 and 16 port boards i duplicated this one and then i just deleted a bunch of stuff and made it shorter to make the 16 port version and then i copied it again deleted a bunch more stuff and made it shorter so what we end up with is we've got that as the um 24 sorry i'm opening some other stuff but not that not that just opening some other things here all right so this is the 8 port version once again i'll get rid of the back layer to make it a bit easier to see what's going on so it's a um it's an 8 rj45 socket thing and the i squared c addresses for the two i o chips can be totally configured using solder pads on the previous version i had pin headers and jumpers and i kind of ran out of space because what i ended up doing was adding a change to this i squared c breakout and put one at each end and just compressed everything and i ran out of space so i ended up going for solder jumpers instead of pin headers but uh that's just the way it goes so there's the eight port version [Music] and now the 16 port version is this one and you've already seen the 24 port version so what we've got now is so if you look at this board that part there is actually exactly the same this is a duplicate of the pcb of the 24 port version with the with eight ports on the end deleted and then just the end of the board moved in that's it so it's exactly the same i wanted it to be totally consistent and so i now have updated versions and this is now as you can see it's up to version 3.0 it'll get released eventually so now i have updated versions of the 8 16 and 24 port boards without the extension on the end and with the i squared c breakouts on both ends so i think that gives a fair bit of flexibility and then what i need to do is think about so going back to this um this version with the breakout on the end what i've been thinking about doing is doing a version of a board that is essentially just this portion and i could do a couple of different versions of it so what i've been thinking about with this is doing one with an esp32 on it and ethernet and that way the light switch controller would have both wi-fi and ethernet and it could be powered using power over ethernet because i put poe in this same area and all it needs basically is a board so this corner board would be something with an esp32 on it an ethernet and poe and an i squared c breakout header and that's it it'll be a really simple little board it's almost like a west 32 in a different form factor and it wouldn't need the pass-through socket on the back that way you could make a light switch controller and do it all with just this board and this board anyway different things to think about so where that is at right now is i haven't yet sent the updated ones off for fabrication i've been kind of sitting on it for a couple of days while i um i think about whether there are any more changes that i want to make or anything else that i might want to have fabricated at the same time but i now have the designs done for version three and also i've oh frank thank you um 50 kanger bucks for the lc fighting fund um yes pancake said the symmetry pleases me yes i also am a fan of symmetry so i when i was laying out this board in fact okay i'm going to show you a little bit of the um the level of pedantry pedantry let's be pedantic about how i pronounce it the level of pedantry that i went to with this [Music] i'll turn that off the easiest way to show you this is in fusion 360. and launching this may stress this little old imac but we shall see adam p said do you ever run into bus capacitance issues with long long i squared c runs the answer is yes and uh i haven't had problems with this sort of size and okay i'm just thinking about how to answer this question because this like this is something that you could chase for a while there were actually capacitance issues on the i squared c bus for the igsat payload processor module and what ended up happening was we had to run stronger pull ups on the i squared c bus and that's because i had 18 mcu no 17 yeah i had 17 microcontrollers on a shared i squared c bus with how many sensors did we have so the reason for i squared c in that case was it was also talking to sensors so we had 17 microcontrollers uh and i think it was five sensors all on the same i squared c bus so they um you obviously couldn't have all the microcontrollers talking at the same time it would cause some problems so there was some some contention handling around that but while i'm waiting for fusion 360 to load yeah so we had some issues with capacitance on that bus and we fixed that by going to stronger pull-ups um [Music] come on fusion but on the light switch controller on the like the prototypes that i've had running on the bench i haven't had that problem is the very short version of the summary all right fusion 360 is slowly slowly opening [Music] and oh we're even in the correct project because this is what i had most recently oh adam said i was using it for soil moisture sensors a few feet away and ended up using the ltc4311 active pull-ups interesting ltc 4311 i don't think i've come across that before while fusion 360 oh it looks like it might have finished opening hooray all right now i'm going to open up several projects here which it might take a while low voltage so the ltc 4311 low voltage i squared c accelerator uh dual active pull up designed to enhance data transmission speed and reliability that's really cool adam p thank you for that tip i hadn't come across that chip before i just loaded the wrong one what i wanted to open was this one and this one and this one [Music] opening opening so so what i have now are four versions of this i squared c rj45 breakout now if it finishes loading all right i'm going to go back to reading about this i squared c bus accelerator um oh okay it's finished all right so this one this is the existing one so this is the version 2.1 with the pass through which is how it was up until you know last week whenever it was before i started my multi-day packing session redoing this now what i ended up with was this which is the new trimmed down 24 port version and you can see it's got the i squared c breakout on each end and then we've got the 16 port version and the eight port version now as i was doing this i spec i was specifically planning that i would put all of my effort into the 24 port version and get it just just right exactly how i wanted it to and then in the schematic i could just delete all of these parts move the right hand edge in and um make the 16 foot version and then repeat the process and make the eight port version so as i was doing that i was planning ahead and you can see here that the left side is the bit that's going to be common to all of them and you can see that there isn't much in terms of silk screen on the right hand side because that was going to get deleted so what i did was i tried to squash all of the useful information onto the left side here and if we come to this one you'll see that it's the same and this one it's the same almost except that i had to make compromises because of those addresses but things like the logo position all of this down here the interrupt header the leds they're the same they're exactly the same and on the back of the pcb this kind of works me a little bit but it makes sense you can see that i put the silk screen on the right so on this one the 24 port version that i did first i put all of the useful information jammed into this third of the board which means that it's across to one side when it's um in the 24 port version but it means that when i deleted the parts and just moved the edge in you can see that these are the same culminating in the eight port version which has the other two thirds deleted and the silk screen on the right part of that is just the same as a silk screen on the others so my goal was total consistency between the three boards and if you look at the that part of it right there compared to that part of it right there it's the same tracks are the same everything is the same i don't know why i'm emphasizing that so much i'm kind of just rambling now and i really should be stopping but anyway my point is over the last week i have been obsessing over the light switch controller and trying to make it as nice as i can in terms of making it flexible like modular like this with the um the 8 16 and 24 port versions of this breakout and modular in terms of what it connects to in the back end so if we go back do i still have my no i close the photo do it does preview allow you to open recent yes it does so this thing here that can be replaced with something different to just plug in a different microcontroller anyway i really need to stop in fact i've got to go somewhere this afternoon and i have a commitment that i need to attend to so i can't just keep talking forever i need to stop eventually maybe one day um aaron said will be an interesting test jig for this bad boy yeah uh oh that is a good question from def pom uh defunct said does it matter that the eight port version doesn't have a bulk storage cap where the 16 and 24 have them that is a very good question and i i went backwards and forwards on that so what i ended up doing okay you can see here on the 24 port version there are box storage caps in between the ports so there are two on the 24 port version there's one on the 16 port version and there are approximately 0.0 on the 8 port version and so the number of storage caps is n minus one where n is the number of uh big chunks of rj45 connectors so what i thought about doing was maybe trying to fit one down the side here somewhere but there just wasn't quite enough room and [Music] so i didn't um i could possibly fit one in here right in the middle so one of the options is if we go back to like the the 24 port version one option would be to put three caps on this version and put them in the space here between these resistors so there would be one behind each of the the ports and then i could have two on this and one on this and i'm this sort of question is the reason i haven't sent these boards off to fabrication yet i'm still kind of debating this sort of thing do i do this do i go to the trouble of putting a bulk storage cap behind each of the ports maybe i will it depends on how obsessive i get um [Music] oh yes so pancake said if you don't already follow at pcb arts on twitter gloriously obsessive pcb designer yes was it pcb arts that did the um the pcb just recently that's got the weird shape cutouts and all of the parts at strange skewed angles that is uh i'm gonna i'm gonna check that i know i really should have stopped the live stream by now pcb arts i will stop soon oh dodgy said what does it store in terms of the capacitance so that is basically just decoupling the um uh it's decoupling for power that feeds through to the light switches that are plugged into here so one of the reasons that i'm kind of debating this is that it doesn't really matter a whole lot those capacitors are not on the power rail for the ics now there are decoupling caps on all the ics see up here these are little 10 microfarad ceramics and there is one near to each of the mcp23017s so they are all nicely decoupled anyway and if you go down to the the eight port version you can see there are decoupling caps here so it doesn't actually make any difference in terms of noise on these ics they're fine what these bulk capacitors are doing these are connected across v in which is you know nominally 12 volts which supplies power out to the i'm actually talking myself out of changing this now so what it's doing is supplying power out to the light switches and at the light switches at least in the passive light switches there is only um there are just leds so with the smart switches there's a microcontroller but with the norm but normally they're it is that v in power is only illuminating leds in the light switches and the leds are constantly on it's not as if they're chopping or anything so they're not inducing electrical noise and the switches are just toggling down to ground when you press them so from a symmetry point of view i like the idea of having a cap behind each of these connectors hmm maybe what i should do is instead of having these big expensive electrolytics i should just stick a small decoupling cap behind each of these like a you know more of these a 10 microfarad ceramic okay i'm going to think about that i'm going to obsess over that and no so it wasn't pcb arts was it greg deville who did the crazy pcb just recently yeah pcb arts on twitter is worth following let's see i'm going to check this out i have a feeling that yeah i can't remember someone just recently was doing a ridiculous pc ah yes here it is it is greg check this out hang on i'll bring this across so you can see it all right now for those of you who are obsessive about symmetry etc this is going to break your brain so this is a render of a pcb design now one thing that annoys me about this pcb and that is the usb connector is straight it shouldn't be it should be on a slight skew but apart from that greg nailed it so i think this started off as kind of a joke and it was like oh i'm going to do a design that's going to make everybody's eye twitch yeah look at these tracks in these these positions oh now with curvy traces so there are curvy traces running through here and this was penalizing it and because the support of the the edge strip of the panel along here had this big gap what greg ended up doing was putting an extra piece in here with a breakaway so there are little mouse bites along here so it can be fabricated and well supported and then this gets broken away and check this out these are the actual boards so this is the bottom of the pcbs and this is the top no there's something blurred out there look at the angle on all of these parts that is ludicrous and this is the board partly being assembled parts at weird angles and oh you can see the curvy traces in there look at this nice curvy traces yeah should have been an april first post yeah except that it's real it's not it's kind of a joke but not a joke because he's actually building it now look at the angle on these parts so pretty yes drc passed clean up [Music] yes ah luke um i don't know if luke's in the chat today but yes luke said should have put a little bit of wonky angle on the usb connector i totally agree ah okay it is it's heading towards 2 hours and 40 minutes of this live stream i've got to stop i've got to stop all right so close to a three-hour livestream and what did we achieve today we achieved two wires folded onto a pcb and a trace on the scope and that's it no these are not the most productive sessions ever but i still enjoy it deathbomb said the board edge is a parallel that needs fixing too i i think that would be the thing that would tip it over in my head and just make it too much you know make it just like a not even it's not a parallelogram but you know just put a little bit of skew on the board and then maybe some mounting holes that are at random locations um yeah okay so just wrapping up um the with the light switch controller before i do sign off uh so um where was it so frank um said just make the eight port and sell multiples as required yeah well originally that was what i was thinking of doing but the problem is that if you want to make something really neat firstly it forces it further apart because you end up with more mounting holes you end up with the little things looped around basically to make one like that you know minus those but one like that all as an integrated board costs less and is smaller and neater than making three individual eight port boards i've got eight boards here i think yeah so that's the eight port version this is the old one you can see it's before the revision it's got the different headers on it and that's the 16 port version so to make three of these and then daisy chain them is more expensive and it takes up more space than making one of those and my thought my feeling is that most people are just going to go straight for the 24 port version anyway i mean it's a reasonable number of switches to have in a house and um you can end up adding more switches just because you can that's the really nice thing about this sort of approach is that you're not dependent on on mains wiring for adding control surfaces excuse me so if for example you think i've got a light switch on that side of the room and i want to put one on that side of the room it makes it really easy just run a cat5 cable to it and plug it in and plug it in at the other end and you've got yourself an extra light switch no mains wiring involved so the result is that you'll end up putting control surfaces in more places just because it is so easy that's what i found anyway so i've ended up with light switches in extra places just because you know it's nice to have a light switch when you walk in the back of the garage and have a light switch in the front of the garage and so yeah it might sound like 24 ports is overkill um but like in a normal house you might think i've got a kitchen a lounge two or three bedrooms and a laundry a bathroom you know it's um i don't need that many light switches but it's surprising you will you will add more aaron says i have 25 light switches no yeah oh yeah so dodgy says 24 by 4 equals 96 yes so this is when i say light switch i mean like switch location and the switch location can have up to four buttons on it so you can have 96 going into this but at 24 locations so unless you want to do hacky things with the wires i'm gonna go i'm really honestly this time i'm gonna go so thank you for coming to my ted talk and i will see you on discord or twitter or facebook or whatever or next week and i hope you have a great weekend and i will talk to you all soon now i've got to figure out how to end the live stream uh adam p yes go to sleep i'd like to all right bye you

Channel: SuperHouseTV

Views: 5,242

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Id: wudnQavHpYU

Length: 163min 52sec (9832 seconds)

Published: Sat Apr 17 2021