@pui4

THE BOARDS HAVE ARRIVED!!! JLC has finally delivered the boards and they look fantastic. But do they work? I will get to that shortly. Ordering the boards was a pain in the ass. When I added the boards to my cart and filled everything in, I got a price of 60 USD. I made my application for a grant for 60 USD and got accepted. Then when I later went to purchase the boards, I got hit with 11 USD of hidden taxes that JLC doesn’t show you until after you have already put you card information in and are ready to buy it. So I was 11 USD short to order my boards; so I made a support ticket on the slack to get my grant increased - just for it to get a couple (honestly useless) replies. So in desperation I looked to see if I could decrease the price to fit inside my grant budget and I was able to using a JLC coupon. So I purchased the boards and received an email asking me the orientation of the single IC that is on the board. They had the dot in the top right when it needed to be in the top left. I corrected them and even attached a screenshot from KiCad to further illustrate my point. They thanked me for correcting them and that was the end of it. Fast forward to yesterday and the boards arrived. I was filled with excitement and I hastily soldered on the headers to the board. I then went to test it with an esp32 and a simple vibe-coded (calm down it’s just for testing) esphome app. I wired everything up correctly and saw nothing on the I2C bus. I was scared I made a mistake but all the voltages and pins were where they were supposed to be. Then I noticed it, the IC was rotated 90 degrees from where it should have been; on all of the boards. It was in the original orientation that JLC sent me and not the corrected one that they confirmed. Even though I don’t have the correct tools for the job I attempted at fixing one. The one with the header already on it would have been annoying as I would have had to remove the headers which is a major pain in the ass. So I stuck another board on top of the hotplate that I got from hackclub blueprint and tried. The first attempt ended in destruction as I was using the wrong type of tweezers and so when I went to place the chip down it pinged off and knocked a capacitor and resistor off the board; and I chose to use absolutely tiny passives as the footprints in KiCad are incomprehensible and trying to compare them to LCSC parts was hard. On the third board and attempt I did (or at least I think I did as I don’t have a microscope to properly check it). I ran over to my computer to test it and I saw it on the I2C bus. Then esphome wasn’t letting me use it as a WiFi speaker so I played some rttti sounds on it and it worked! Of course all of this time was not logged (4-5~ hours of work) so what was the 1 hour and 25 mins. Well the original purpose for this board was to be used with Linux SBCs and so I tried to get it to work with the pi zero 2w. I picked the 2w to test with as it has 6.18 kernel which includes a driver for the es8311. However I know next to nothing about Linux embedded development, even though I’ve dail drove Linux on my pc for almost 2 years now - I know it more as a user than a developer. In other words, I couldn’t figure out how to properly write the device trees to get it to work and I couldn’t vibe-code it either as that didn’t work. Now I have to try and get this working on the pi before the end of Star dance so I can ship it. If you are reading this and have any experience in embedded Linux or device trees, please message me on slack: @pui4. Thanks for reading, I hope to get this done soon. Also I have sent an email complaining about the boards to JLC and I will report when I have any news.

Finally going to submit!! I’ve finished the PCB and the readme (for now). I made blender renders of the PCB. I used a random HDRI I found online and hit render. Also I had to change the PCB as the footprint I was using for the resistors and capacitors were too small for the ones that I actually wanted to use. In fairness to me; it’s difficult to pick the right one when all the footprint names are “R_0201_0603Metric”. It’s so confusing that even claude got it wrong. It said that the second number was metric and the first was imperial and that LCSC has there components listed in metric. That’s wrong, I’m not sure what part of it is wrong - all I know is that the number I wanted for LCSC was the first one. I also changed the footprints so they aren’t the hand-solder ones. This is after @heki told me that it may cause issues, yesterday. This will not be my final post on this design as I guarantee that there will be some issue with the design or repo that requires me to re-submit but we’ll see. I also updated the readme to a some-what final state (until I actually get the boards). It has more info if you want to check it out. The repo is a bit messy at the minute so I need to tidy that up at a later date. Now I just need to wait to get it rejected to do any more work on it. Until then, thanks for reading !!

I think I’m done. I finished the PCB and fixed some things with the help of @heki (thanks). I did a BOM with the help of the JLC kicad extension and uploaded it to JLC and got a price of $40! I still need to do a render and submit it but I think I’m done for today. Thank you for reading. (I spent a lot longer on this but forgot to record it)

Hopefully finished routing the PCB. As I said in my last post; I’m not entirely sure on if I have picked the correct footprints for my resistors and capacitors. I picked small ones as it won’t draw much power and is 3.3 volts anyway. Also I ended up keeping the aux jacks and fit them in as shown in the screenshot. Next I need to make a BOM for JLC to assemble it as I currently don’t have the capabilities or expertise to solder SMD components. I have never made a BOM before and I don’t really know how to start - if anyone can help me, please comment on this post or reach out to me on slack. After the BOM is complete, then I will need to see the cost of producing these modules and submit the project for funding. Also excuse the poor quality of my routing and the large amount of Vias, as this is my second PCB ever and I’m just learning by trial and error. I mean my last PCB worked (with some bodges) so surely this vastly more complex one will work too; right? I also need to add some art to the PCB as currently it is very bland (yes the text is in comic sans). I will also do a render in blender and properly add the models for components in a future devlog. I’m also going to post the PCB and the schematic into the slack to see if their is any obvious issues that I have overlooked. If you (the person reading this) spots any issues - comment them or reach me on slack. Thanks for reading and hopefully I’ll get this done soon. :))

(little annoyed as I am having to re-write this entire thing again as stardance refused to accept my last one) I have just finished the schematic for the module. It is copied from an implementation by waveshare in one of their ESP32 boards here. I’m not 100% sure that it is correct as I’m not good enough at electronics yet to read and understand datasheets. I haven’t yet assigned the footprints to the symbols yet as I need to do more research into the different sizes of SMD resistors and caps. It has 2 aux jacks - one for input and one for output, I’m not fully sure whether or not I’m going to keep these in the final design as they are already broken out to the pin headers; but they are there for now. They are also TRS jacks even though they are both mono, this is due to me requiring a TRS jack for the mic I plan to use for my other project (a Rode videomic shotgun mic). I know that a mono jack would work too, but I’ve chosen to use TRS jacks also because they are easier to obtain. The pin headers are separated into 2 groups of 6 as to keep it small and bread-board compatible - so I can use this module for prototyping other projects more easily. Right now I’m going to submit this schematic into the outpost and stardance slacks to ask for others opinions. I have no intention to go to open sauce as it is too expensive for me to go as I am in the UK; so I’m hoping for as much star dust as possible :) If you have any questions (or you spotted an issue in the design) feel free to reach out to me on slack @pui4. Thank you for reading and being interested in my project :))