Lowest Power (~3uA) MOTION Sensor - WiFi Connected with trigBoard

so anytime you're working on a battery powered project it's important to keep an eye on the standby current which is the current draw from the battery when just sitting there all day long doing nothing so in the case of motion sensors this can can be kind of challenging because the pir or passive infrared sensor here needs to be always on watching the environment so what i'm going to show you here in this video is a few different sensors but specifically here this one here in the white box is a super high performance pir sensor hooked up to a trig board powered by a lithium battery and i use these all over the place like in hallways along staircases you know anywhere where i don't have a physical door and i want to monitor that or even like a room that's barely ever used that if anybody ever enters i would get a push notification immediately so if we pass along this sensor it wakes the board up connects to the wi-fi and sends a push notification out to my phone immediately within five seconds so i'm going to show you all of this here so let's go ahead and get started so the first one i want to talk about is the am 312 based pir sensor which you can get from amazon for super cheap i buy these up all the time and use them you see two for just about eight dollars and their low power performance is actually pretty decent it's about 12 microamps but let's actually hook up to it and see what it is all right so i've got the sensor hooked up to a trig board here which is obvious you know the trig board has world-class low-power performance it's only pulling one or two micrograms from the batteries so the rest of the standby current is going to be from the sensor and we have this powered up from a power supply here the ot arc and you see a 3.7 volts which is like a typical lithium battery uh we are pulling an average current of only 13 micrograms so that's incredible right there even with a super cheap sensor like this and this will last probably you know many years depending on how often it wakes up so if we pass some motion in front of it you see there on the ot arc it i'll let this go for a little bit there we go zoom out and you see here it woke up connecting to the wi-fi network sending out the push notification and did all of that in about uh five and a half seconds there so that's pretty good and the average current even through that was about 40 milliamps so there you have it even with a super cheap sensor it is possible to get very long battery life but let me step this up big time here so before i reveal the part here check this out we're applying the same voltage here 3.7 volts and you see it's got an average current of just about 3 microamps that's right single digit micrograms from an always on pir motion sensor and if we put some motion in front of it there you see it wakes up trig board gets the push notification out and goes back to sleep so total time there was about two seconds now keep in mind this is also using a different uh type of system this one with the am 312 was waking up connecting to a wi-fi network and then sending the push notification out through pushover this one here is set up to wake up and connect to a local network here i have and send a udp packet to an uh to a gateway and then that sends it out via cellular uh network a totally different system and i've also talked about that as well and i'll i'll leave a link in the description below on on how to set that up as well but anyway that's pretty awesome so sleep current is about 3 micrograms the on current average is about 60 or so milliamps but you see it's only on for two seconds if you build the system this way so you can just imagine what kind of battery life you can get from something like this now of course when you see three microamps you've got to be really obsessed with low power and you're gonna pay for it because this is an ultra high performance panasonic pir sensor here which has a sticker price quantity of one from digikey of just about 34. so it's very expensive as compared to the am 312 sensors over here so checking out the data sheet you see the one we're using is right here at two microamps now believe it or not they've got a one microgram sensor and you can see it here it's just like you know a dollar or so more than the 2 microamp one but they weren't in stock when i was uh buying these so oh well i went with the 2 microamp sensor which in the grand scheme of things won't matter at all but they also have a six microamp version which is kind of cool and that one is you know 25 or so so it's a significantly cheaper but still very expensive as compared to the am 312 sensor so you're really gonna have to want this in order to use it but there's a it's not just about low current here these are very advanced uh sensors you see they've got there you see it resistance to electromagnetic noise you know so you don't get all the issues you have with these cheapies you know with them false triggering on you or or getting into this weird death spiral sometimes where they just continuously trigger over and over and over again uh so so far i'm very happy with this it's kind of one of those things you just set it up like i keep this kind of just tucked into the the stairway there and you know just set it forget it probably won't change the battery for you know many many years uh so anyway i just wanted to share that with you and uh let me just quickly go over to the docs page and show you the uh the build here so as always over on the trig board v8 docs i've got this project documented over to the left here motion sensor pir and i've got both of these i've got the high performance option as well as the cheap option with the am 312. now i really like the high performance option because these sensors have a full swing output meaning they go from their vcc voltage down to ground so it hooks up perfectly to the trig board you see ground you wire over to the ground pin the output right into the sensor input here and then vdd we can also grab from the sensor as well and you want to watch your polarity here because a lot of these jst plugs you know are switched around so look at the board and you'll you'll see you know plus and minus there and just make sure you wire it up properly now the am 312 does not swing all the way up to its vcc it only goes up to like 0.8 or 0.9 volts so you can't hook it directly into the sensor input on the trig board you have to sort of do this kind of circuit and in this example we're hijacking the wake button pin i'll talk about that in a second here so the panasonic sensor is nice i just used my standard 3d printed case that's available up on the tindy store poked some holes in it stuck it through soldered up a couple wires to the other end you know jst cable there for power and the output and then just one extra wire for ground wire that on over to the trig board little tiny uh 1 000 milliamp hour battery buttoned it all up hot glued the sensor in and i was done and there you have it you see we've got the battery down in there fits perfectly trigg board up in its tray yeah we just stick the whole thing button it back up and there you have it now you can just tuck that anywhere you want and you're done so we'll just quickly talk about the am 312 circuit here that i mentioned so it looks a little complicated here you know we can't just hook it straight up to the sensor input like the panasonic sensor and that's because the output only goes to like 0.8 or 0.9 volts that's not enough to wake it up from a sensor input we could do it by adding a transistor or something but in this example here i just decided to use the wake input and you see the diode here and the purpose of that is so that when motion is detected here we can wake it up we have like one volt or so right there which is enough to wake up the trig board so it's doing a kind of uh in parallel with the actual button itself but when the pir is just sitting there no motion is going to have its output pin at about 0 volts now if somebody goes and presses the wake button then we're going to have 4.2 volts right there and that would be a dead short to the output pin of the pir which would damage it so how does the trig board know if it was a wake button input or a pir wake uh well as soon as it wakes up it goes and does an analog read on digital pin or not digital gpio pin 39 and it'll do an analog read there and if it reads about one volt or so it'll know it is a pir awake otherwise it was a wake button wake and i do have this code here posted right here motion sensor code so it is a a slight change there to support the am312 with this wake button input but it's super simple so your choice if you want to use the super high performance panasonic sensor you got to pay for it but it is really cool and for something that you're just going to set up set and forget you know it's kind of nice having something that's only pulling three microamps and by the way i will make a version of this supporting the am 312 using the sensor input with some kind of transistor or some kind of circuit you know so that it just makes this a little bit easier or you know at least what's nice about using the sensor input is that you don't need to use this uh the the variation of the base firmware to detect if it was a button wake or a pir wake so anyway i just wanted to make this video and show off this super cool sensor and that was pretty much the reason i made this videos was that i found this super high performance pir motion sensor that i didn't even know existed i mean total current 3 microamps that's totally crazy so anyway hopefully you found this video interesting thanks for watching

Channel: Kevin Darrah

Views: 5,127

Keywords: trigboard, wifi, motion, sensor, low power, battery, PIR, panasonic, EKMB1201111

Id: SQ18kfBg6I8

Length: 10min 28sec (628 seconds)

Published: Thu Nov 05 2020