ESP32-S3 + Chip Antenna PCB - Design your own in 15 minutes!

hey guys I just wanted to say thank you for all the support in the previous video and because many of you asked for a run through of the design I'll be showing you how I built this custom esp32 S3 development board in key CAD 7 I'll also be showing you just how easy it is to order complicated boards like this from this channel sponsor PCB way but more on that later oh and before we jump straight into schematic I just wanted to let you guys know that if you aren't subscribed already please do because in my next video I'll be incorporating this board into my best line fer yet as you can see we just have this main esp32 S3 chip right here with an integrated 8 MB of PS RAM and I've just labeled all of these pins here using the L key so I can make connections to them later also I'm not using uart so I left that disconnected even though the guidelines don't really recommend for you to do that and I was too scared to use the JTAG pins as gpio iio 33 to 37 are also taken up by the octal PS Ram so I couldn't use those either here we have the zero ohm jumper resistors out of the pins of the esp32 S3 which I guess I meant to mitigate a couple issues like RF interference timing and driving current they simply just rout into the pins of the chip I'm using using the w25 q128 jvp IQ in the wson 8 package and I've also added a pullup here on the chip select zero pin so that the flash is clearly enabled or disabled by the esp32 S3 chip of course there's also got to be some filtering before the 3.3 volt Supply reaches the Chip And here are all the components you need which are straight from the hardware guidelines basically just some decoupling capacitors to make the power supply more stable and an LC inductor capacitor circuit to suppress harmonics something that I feel needs to be included in every es32 S3 design or at least every working one is a boot Button at the very least and an optional reset button this RC circuit here delays power up of the chip so that the power rails can stabilize before startup and this 10K 1 microfarad combination is pretty solid and used in most designs in case you didn't know clicking the boot Button lets the chip know that you want to download a program and clicking the reset button simply Powers off the chip the boot Button is connected to gpio0 meaning that it doubles as a user button after reset now my power circuit on this Bo board is actually more simple than you would expect mainly because I didn't include a Libo charging I see and instead opted for voltage Regulators that could handle Much More Voltage than the ones normally included in esp32 boards you see just like most arduinos I wanted to be able to plug in USB or multi cell lipo or both with this wide range of inputs all being regulated down to 3.3 Volts for the esp32 this is because I like to make moving robots like line followers which often require that higher voltage from the lipos to run the DC motors luckily the Tov 767 drv series can handle up to 16 volts in a 2x2 mm package and will either output an adjustable voltage or fixed one at 1 amp keep in mind though after some testing I realize these tlv 767 Regulators actually get concerningly hot when plugged into 12 volts so I'm not sure if I could recommend commend them to you guys anyways they still worked in everything and I only need a small output capacitor and an even smaller input capacitor to get them running the voltage in pins which will connect to a multicell lipo are broken out on these double headers which I'll explain later now what's the second power input of course it's the USB port which will give us a nice steady 5 volts something that doesn't make the ldo as hot I chose type c since it's the standard nowadays and I just need to add these 5.1k pull down register on both CC pins to negotiate for 5 volts add up to 3 amps this is an absolute must for USBC so if you make your own design make sure to add these pull Downs if you only want 5 volts so vbu goes through shocky D to the voltage inpin to prevent nasty things from from happening and as you might be noticing I have a fair load of ESD protection on this board first there's a TVs di on the voltage inpin since that makes a lot more physical contact as there's a battery that will be plugged in next there's this USB lc6 2p6 ESD protector to protect the USB port itself and I actually learned about this part from unexpected makers Pro S3 schematic make sure to check it out if you want to learn some more from an actually professional person I'll link it in the description next we got this Crystal here with a series resistor to reduce harmonics and some load capacitors which you can calculate the value of using this equation this Crystal actually seems to be quite small compared to espressive own design but it still ended up working pretty nicely because it was obviously 40 MHz audio 2 is basically the same as the main LD same part number and decoupling but it Powers the magnetic buzzer and neopixel led instead which is what I'll be talking about next now this buzzer the CMT 0525 75 smt TR quite a nice name there draws up to 200 milliamps definitely not the same as a standard buzzer which can just be powered directly from an IO pin so I had to end up using an npn transistor here which is switching the low side of the buzzer basically one of these pins always has a 3.3 volt Supply but the circuit only completes when Ground is connected with this npn transistor we of course have the same shocky di that I use on the USB port here to protect the load against reverse voltage and a series resistor from the base to the corresponding ioin for the buzzer so that we don't get free pollution and toxins seeping out of the transistor you may be asking now how will the esp32 S3 have RF capabilities without an antenna well here's the antenna it's a 2.4 GHz chip antenna which I used because it's way smaller and well I don't know how to implement a PCB antenna yet so from the LNA inpin of the esp32 there is this first matching circuit here to match the 35 plus j0 ohms output impedance of the esp32 to 50 plus j0 ohms the standard value as input to an RF antenna and then this second matching circuit here to match the antenna to 50 ohms which I've left as just a zero Ohm resistor at the moment because I don't have a VNA unfortunately and the data sheet of the antenna provided no example values I calculated this first matching circuit with a Smith chart instead instead of one of these kind of calculators since I can input real world values for the components in instead of rounding from exact calculations and perhaps getting a worse match although the Q factor does need to be taken into consideration more with this method the headers are just standard 2.5 mm pitch but they have two rows so that more gpios can fit in the space that I've given myself that unfortunately means that it is not RedBoard compatible and it isn't perfboard compatible either since I messed up the spacing all right it's that easy to make the schematic for your very own esp32 S3 development board let's move on to the PCB design now now I would like to say that I did this programmatically but that just wouldn't be true I placed the components and started writing a couple times before realizing my component placement or Footprints were bad and then starting all over over again but this is what I ended up with so as you can see on this top layer right here we have the gpio from the chip going straight to these double row headers and I think it looks pretty cool the way that a bunch of PCB tracks piled together often do next I did the differential pairs for USB which I calculated using PCB ways online and penuts calculator and found that I needed a trace width of2 mm and also a gap of2 mm M which made things pretty easy and I know some of you might bug me about the fact that it isn't completely surrounded by a ground plane but I honestly don't care the overall length between these two differential pairs is literally 1 cm or4 in which is pretty big but not big enough to need complete adherence to the guidelines unlike longer USB traces another instance of the you don't need to follow the rules if the traces are really really short is here with the flash chip it's quad SPI literally the fastest signal on this board apart from maybe the Crystal and I routed it between traces like you're definitely not supposed to do that either but I saw expressive do it in their own wrom module so I figured it couldn't be that bad and it turns out it wasn't and I could upload at 921 600 B easily which was a nice surprise you also May notice that the Flash ship isn't grounded through Trace it's actually grounded through Vias which go to the ground planes on the layers below again I'm pretty sure this isn't good practice but it might not be too bad I mean after all it did work completely fine next we got this Crystal right here the most sacred part of the entire board the part of it which could mess up almost every signal and the RF and it was as simple as just isolating it from the top Grand plane us using again grounding vas to The Copper planes in the lower layers as expressive recommended in the design guidelines there's not really much to add here when it comes to the buzzer or the buttons as I kind of just ratted them willy-nilly only making sure that the traces were thick enough to handle the current so the last part I'll be talking about for this board is the chip antenna first we have a keep at area here for the antenna to radiate better and I followed your Hansen Technology's data sheet for this one and if you want to know this is the 24508 18 d0100 antenna a keep out area is when no copper is allowed in a specific region of the board and in this case it affects all layers within the 4x6 mm Zone well kind of obviously the top layer still needs to have the traces rooted so in those areas there is an exception the antenna matching network was placed pretty close to the antenna itself and the chip set matching network was placed close to the chip so we have this long curved Trace that is hopefully matched to 50 ohms between the two it's a c-plan or wave guide type Trace which I calculated online using command's calculator and it's curved because apparently sharp turns is bad for the performance keep in mind via stitching Trace rounding and some other R capabilities like the ones I used are not available in the standard version of key Cad and you'll have to download a package to add to it which I'll link in the description below since I won't be tuning this antenna matching Network though it'll probably perform pretty badly so I'll just have to hope it doesn't damage anything so what are all these holes in PCP design especially in RF and mic controller boards you need to have grounded stitching vs all around the antenna feed line as as well as scattered amongst the board as much as possible because this connects the four ground Planes together and minimizes impedance for a turn current anyways that's basically how I did it so here's how I ordered it using PCB way first I exported my Gerber file and uploaded it to the quick order page selecting the impedance control option as well as how many layers I wanted the color of the solder mask and the copper finish among other things for the assembly I need to follow this simple PCB way build of materials template which I spent about 3 hours on because I didn't think to add the part numbers while making the schematic and quite frankly I still don't know how to silly me then I uploaded the bill materials to the assembly section of the quick order page I waited a day or so for them to review the file a process which only happens with more complicated boards like this one and it turns out that I forgot to provide them the impedance information in the Gerber file so I sent some pictures of the necessary tracks to be impeded smatched and they also spotted one ER in my bill materials which I quickly clarified and then they were ready to start manufacturing it about a week later I received it and if you also want to get great quality pcbs make sure to sign up to PCB way using the link in my description thanks for watching guys

Channel: Haase Industries

Views: 7,195

Keywords: esp32, arduino, internet of things, arduino project, arduino fun, arduino uno, arduino nano, esp32-s3, esp32-c3, esp32-s2, esp32-c2, esp32-p4, esp32-c6, esp32-c5, esp32-c61, PCB, PCB design, esp32 tutorial, esp32 tutorial step by step, arduino esp32 tutorial, esp32s3, electronics, esp32 project, esp32 projects, robotics, robot, robots, robotics engineer, arduino tutorial, arduino projects, espressif, esp32cam, esp32 cam, esp32 cam projects, esp32c3, esp32 s3, esp32 c3, esp32 s2, esp32 p4, esp

Id: xK14eVJCoqU

Length: 14min 18sec (858 seconds)

Published: Wed Jan 31 2024