How To Make A Custom PCB From Design To Assembly

the following program is brought to you by element 14 the electronics community where you can connect and collaborate with top engineers from around the world join now at element14.com presents welcome back to element14 presents i'm clem and in this episode i'm revealing a big secret that you have been asking for on the element14 community amazing hacks inspired designs each week element 14 presents brings you innovative projects using electronics engineering and more [Music] in a lot of episodes you see me use custom electronics like this pcb that i designed and often it seems like snap there it is i came up with a schematic and now it's a pcb and repopulate it and that is for the project but actually there's a lot of work that goes into designing one of these so in this episode i'm taking you with me on the journey through every single step of coming up with a schematic making that into a pcb fabricating it populating it and even program it and test it and then you may come up with your own ideas for custom electronics and maybe you even got a product that you can sell and get rich and be like like rich and successful people not like me like real people let's go to the computer and start okay let's get started in this video we are making our own dev kit featuring the new esp32 s2 so we're making an iot dev kit of course there are some of the mark on the market like this one but there's a special gripe that i have with this if i use my breadboard like all people do and i put it in i basically have nowhere to connect my cables it takes up almost the entire width of my breadboard so that's not good and also it uses an external communication chip for usb to uart but this processor has native usb so of course i want to take advantage of that and i want it to be breadboard friendly so i can easier prototype as we see applications oh and also it's micro python compatible so hey that's always a bonus so if you are watching this on youtube or on the element14 community as the main video you will see all the highlights all the major steps that go into this design if you are watching this as the bonus content on the element14 community you see all the steps the unabbreviated version going with me through every single piece so basically like you would watch it live so let's start i've opened kycad and made a project i call this green accent clam and we start by starting a schematic i've chosen this simple project because that's easy to follow and the general workflow and all the things that i do apply to every kind of project so first we need to decide on parts things that we know the processor that we are going to use it's esp32s2 and i'm using the room module and i hate i really i don't hate micro usb per se i like mini usb more and usb c but i hate flimsy usb ports and there's nothing worse than plugging your cable working with something and then suddenly the usb port rips out or even worse it doesn't rip out but it loses connection so you don't realize that right away so what i do is i use usbc and i use the most rigid connector that i could find on funnel which is the 105 450101 that's a usbc connector made by molex that's a low dropout voltage regulator an ldo 3.3 volts output and it has 500 million pairs of supply current why 500 first usb standards are limited to 500 if it's not like one of the power delivery standards so that's always the maximum that we get and the module itself will need about 250 to 300 mic milliamps when it's doing wi-fi full throttle so we have a little bit of reserve for powering other stuff that we use on the breadboard of course i need a ground connection that's everything it needs to work but to enable to be able to program it i need to have connection either rxtx for serial communication or i use io19 and io 20 for data minus and data plus for the native usb keep in mind you need to first activate that native usb when the chip is brand new so i need to have a way to talk to it before that so that's why i'm also bringing out rx and tx and i also need to the flash line connected to gpio0 if gpio0 is low on boot the chip will go into download mode and that means i can program it d plus of course these are the data lines for usb use w to make the wire say okay that's plus that is also plus and third one is minus and that is also minus actually two of those wire them in and the first one is 5 k1 which means five point one kilo ohms and the other one is us uh we have a little five point one uh not five point five k one you basically use the k as a decimal point so it's easier to read now that we've made a schematic we need to tell the program what those schematic symbols correlate to in the real world so what we do is after annotating it yeah i have some errors in my in my files don't don't look at that too hard so what we have already done is associated that special molex connector with that pin out and also the esp with the right one these are things that you won't find in the kaiket libraries for your first project stick to parts that you find in those libraries because those are already known to work except for some little parts i've noted that in another episode like the ina 219 that doesn't fit right with me and then we have the mcp voltage regulator and now it's the question there are a lot of different pin outs so we have to look up which of these it is in my case it should be the 223 free tab pin that's it so tap in two means number two is also the same uh pin number two is the same like on the tab that is connected to the ground plane so in some uh ldos that is different so be aware that you use the right one for your lowdroppers voltage regulator and now we go into pcb new [Music] so now we're in pcb new and we start by setting up the environment here's the net file that we saved before we can always look if there are some errors so the actual microcontroller is inside the breadboard so you get maximum breadboard space and for doing that i need to have the shape and i get that shape from a vector drawing that i'm making inkscape to keep with the open source workflow and then i convert that into a dxf which is a proprietary format by autodesk and then i can import that dxf file into pcb new [Music] and if i now move one of these it snaps to the nearest increment so this is the middle of the of the pcb and we can just place it here and place another one in the desired location and now they should pretty much line up problem here you see they don't line up vertically and that is because i move them when the raster was set differently you know what let's put it over each other then change the raster and then move it away okay and now the spacing should work that looks good okay now we need to find out how big that spacing actually has to be [Music] and just need space for one more pin oh come on really don't oh that's it okay i thought about it and you know what losing one row on the breadboard is okay for having it consistent and not making it a four layer board or some weird budgets let's just put it one row apart and then i should have enough space for all the traces that's awesome and now for the most satisfying thing that you can do when you've done or came this far into a project go to the 3d viewer we can see this side of the board is basically void of components and we have some big uh places where we could uh we could put stuff these beers uh vias are for heat transfer okay that looks pretty good so i could now take this design and directly shake it to icelaw and let them manufacture my boards i can even get a stencil i can get the parts directly i could also let them assemble it but first and that's crucial for every one of these projects sleep over it watch my video on 20 or 30 pcb fails and check your project for those fails i will also do the same sleep over it and tomorrow when i have taken another look a distance look on this project i'm going to upload it to asla and get it manufactured [Music] we are ordering the boards at iceland.net and as you can see i did not make any gerbers for it i can just upload the kaicat pcb file and iso processes it and automatically assigns the footprints so that's actually easier and if i want to change it i can just add another revision i don't have to keep track of different versions of gerber files also i can't do any errors with the gerber export settings that happened before to me so that's a lot easier and this method also supports assembly so you don't have to make special files for that that's pretty cool so the board is in here we can see that our board would cost 25 euros and 47 cents and if we check the gaba viewer we can see how it will be processed we can turn silk screen on and off turn the pcb around i don't find the right ones here so i go to lemon14 take the order code and i should be able to put it in here and that should be that part yep that's the part and that's how you get the right components and that's it okay and now i wait for the parts let's cut to future clan in a shocking turn of events the pcbs have arrived from germany looking good and now it's time to apply the stencil so i've ordered the stencil with them put that in a jig that uses up some old pcbs from previous project align it and then i apply carefully the solder paste just using a piece of another stencil as a squeegee but a credit card or something similar would work also and as you can see we have now a perfectly stenciled pcb now it's time to place the components printed off the schematic always helps identify the parts identify where they go on the board here and here and place them carefully [Music] next one these tiny components are 0.603 so be careful they might get lost here are two caps and if something is upside down just drop it and it may fall into place this is the low drop a dropout voltage regulator usb make sure that that is perfectly placed because those tiny pins need perfect alignment now the mcu module and off to the old pcb grill [Music] i've tried out this solder profile before so why not use it check if it's okay looking fine [Music] and now we can inspect the board you see the resin based flux on there that has to be cleaned off but all the solder joints look fine and also keep additional parts [Music] the board is basically finished except for the hole components and now you can decide which way around you want the buttons to go you can put them on this side or on the other one [Music] stick in some headers to get perfect alignment for the pcb [Music] first one is to tack it in place and then you can solder the other ones and now we can remove it from the frame that is also only needed because the pcb has a special shape and now we can clean it i use a ultrasonic cleaner and some isopropyl alcohol for that by the way never do that and then i scrub it with my toothbrush or someone else's somebody else's toothbrush we can apply power with usb-c and open the arduino ide it's important that you hold down the flash button and then push reset to get it in download mode and now the arduino ide we make sure that it shows up meaning yes that is in download mode over the native usb also make sure you have the esp32s2 boards installed and select usb cdc for the native usb so it outputs over the serial on the right port and when we program it we encountered error it says no reset but actually that's intentional because we want to reset it when we do it so just give reset a little push and there our blink example works and also if we look at the serial monitor we can see the serial communication is working and it's putting out the state of the led awesome so today we have gone from this breadboard unfriendly dev kit to this very breadboard friendly iot dev kit get it iot german word for egg that's why it's egg shaped and also it says the yolk of die project on there and this one is perfectly capable for bread boards it doesn't take up any additional space only what it really needs it has native usb it doesn't have strange autoresetting it only resets when you want it to so you can keep your serial connections and stuff for iot projects that's pretty important and you can also assemble it in different ways to suit your needs maybe you're a lefty like me and you want your cable the other way around or your right hand person or you just prefer it a certain way you can pick and choose also i think it's even more inexpensive to produce than the original one meaning yes i'm going to make that available so eventually you are able to buy that one if you don't want to uh design your own but hey this is the open sourciest dev kit that you can ever imagine because you have witnessed the full design process of this there is a video on the element 14 community with the unabbreviated many hour long version where you can see every single step every nook and cranny that got into this design and yep it's readily available and if you want to get notified when that goes live check out the element14 community and there's a link for a newsletter list that i put up today we made the open sourciest dev kit there could ever be you've seen the whole process all the files are available at element14.com also there's a link where you can get the pcb at isla and if you don't want to build yourself but just use it you will be able to buy that eventually i gotta go there's another project waiting for me and if it happens to have wi-fi or native usb or needs a fast easy to use processor i've got a dev kit that makes my life a lot more [Music] easy [Music] you

Channel: element14 presents

Views: 15,538

Keywords: electronics, hardware, hacking, mods, weekly, element14, maker, engineering, element14presents

Id: JCmg-18BxTU

Length: 19min 21sec (1161 seconds)

Published: Fri Feb 12 2021