u/cyao12

Wanted to try out these CH32V203 (144MHz RISC-V) chips for a while, so I've decided to make some nice USB gadgets for USB HID injection and just for studying the USB protocol. It has 2 leds and 4 captive touch buttons.

It fits nicely into a USB-A port and is very easy to carry around. And with it I've had tons of fun messing around with a bare-metal USB stack, and just in general learning the whole USB protocol.

It was really fun trying to make a bare-metal USB bootloader for this chip, but I've managed to fit everything in 2KiB. (Source here) For comparison the official bootloader is nearly 24KiB in size. As a bonus, I've also re-designed the V203 USB stack for ch32fun and sent in a pr :D

The PCB is also open source, check out the KiCAD files here: https://github.com/cheyao/comu (kicanvas)

I plan on just using them for HID injection and as a quick devboard when I need very few I/O pins (4 main ones, but I've exposed some more via testpoints)

(Name and form inspired by the *omu series)

Wanted to try out these CH32V203 (144MHz RISC-V) chips for a while, so I've decided to make some nice USB gadgets for USB HID injection and just for studying the USB protocol. It has 2 leds and 4 captive touch buttons.

It fits nicely into a USB-A port and is very easy to carry around. And with it I've had tons of fun messing around with a bare-metal USB stack, and just in general learning the whole USB protocol.

It was really fun trying to make a bare-metal USB bootloader for this chip, but I've managed to fit everything in 2KiB. (Source here) For comparison the official bootloader is nearly 24KiB in size. As a bonus, I've also re-designed the V203 USB stack for ch32fun and sent in a pr :D

The PCB is also open source, check out the KiCAD files here: https://github.com/cheyao/comu (kicanvas)

I plan on just using them for HID injection and as a quick devboard when I need very few I/O pins (4 main ones, but I've exposed some more via testpoints)

(Name and form inspired by the *omu series)

I made a custom one as none on the (limited) market could offer what I needed:

The top part is the main nRF54L15 board with a nPM1300 PMIC that let's me charge LiPos directly via the board. It also has a integrated antenna, and can be broken off from the bottom module to be used as an standalone board. It also has castellated edges so it can be directly embedded onto circuit boards. (I plan to do this for my future projects)

The bottom part is a nRF52820 powered CMSIS-DAP probe that let's me debug the nRF54, as the nRF54 doesn't have a USB PHY. I designed it so it can be broken off and used as a standalone board, w/ the antenna exposed via the U.FL connector :D

The sources are also open source here: https://github.com/cheyao/nrf54l15-discovery (To my knowledge the first open-source project with PCB files except Nordic's example)

BTW, future project ideas with this would be appreciated! I kinda forgot what I wanted to do as it took the parts nearly 2 months to arrive lol.

I ordered around $300 of electronics from Hong Kong, and the shipping is not DDP. Customs was expected but what is shocking me is the $110 of service fees. It's almost 10x the custom amount!

Any way I can not pay the fees? Or a chance that this is an error?