12/29/2025 - Worked a lot on schematic

I picked the MCU, and finished the main 'devboard' part of the schematic. The USB-C, power, crystal, decoupling capacitors, and even an IMU. It was lowkey way harder than it was with the RP2040 tutorial since I had to scavenge the information myself through datasheets and stuff, but I think it should work. However, it's left me a bit hungry for more features. I'm thinking I may add some FETs to GPIOs that are integrated and flow from VBUS which would be cool, and dedicate towards more of an educational board. Or, I might just convert it into a flight computer. I honestly don't know at the moment.

12/30/2025 7 AM - Converted to a flight computer!

I added in the barometer and microSD card readers, effectively converting it into a flight computer! There are still a few more features I'd like to add, but at the moment it's looking pretty good. Mainly it needs a battery charging IC and some integrated FETs.

12/30/2025 8 AM - Finished the schematic

Added in battery management, servo outputs, MOSFET controlled outputs, and a 5v buck/boost. I also organized the entire schematic and finished it up. I'm pretty happy with how it has turned out and it looks like it will be a useful flight computer/controller.

12/30/2025 9 AM - Assigned footprints

Assigned footprints for all parts + double checked LCSC datasheets for a couple of the parts. All the footprints were surprisingly easy to assign this time around.

12/30/2025 10 AM - Finished layout of the board

I placed down the main chips and STM32 decoupling capacitors, as well as a couple LEDs + resistors. I went with a skinny, filleted design because I feel like most flight controllers I see are fat and rectangular, so I thought it'd be a nice refresh. Other than that it's time to start the 12 hour routing process, but I'm happy with it so far.

12/30/2025 11 AM - Added passives layout

I guess I didn't REALLY finish the layout last journal, since I didn't add the passives or anything. But now I finally have and everything is placed in at least the general location that it will be. Now, it is time to start the horrible excruciating process of routing all day long.

12/30/2025 8:19 PM - Finished routing

Finally finished the routing! It wasn't actually that bad compared to the RP2040 devboard. Probably because it's a bit bigger and also the STM32 doesn't place power pins right next to each other so you can actually put the decoupling capacitors where they should go. But I got it done, and made it 4 layers and did a power and ground fill.

12/30/2025 8:29 PM - Added silkscreen/polish

Polished up the existing silkscreen (removed clutter...etc.)
Also added some text to the PCB. Otherwise, it should be finished and I'll prep the repo to submit.

1/1/2026 - Made files/checked prices/tested on JLCPCB

First I made the production files, edited them, and then realized my microSD card reader was placed sideways. Because the no-place zone inside the reader looked like the shape of a card, I rotated it sideways. So I first redid that, and then made new files.

I uploaded it to JLCPCB, and made the BOM. The total is around ~$120 for 2 assembled boards.