This is not my project, however it was publicly shared in the following link https://www.parkytowers.me.uk/thin/wyse/3040/storage.shtml I have tried myself to order the board and got an error saying that this is someone else’s project and was not shared, hope I did no wrong by sharing again.

for (tr)uSDX Y1 TCXO mod: two 0603 0.1uF’s (eg TMK107BJ104KA-T, or 0603YC104MAT2A, get 10) & one 27 MHz tcxo ie ECS-TXO-32CSMV-270-AN-TR; I’d solder tcxo first, it’s all very small

Voltage reference board, drives two PitchDAC18 with precise +5V and -5V

Seeed XIAO-ESP32C3 and EByte E01-2G4M27SX for open-source AhoyDTU to monitor Hoymiles inverters.

BOM:

• XIAO-ESP32C3
• E01-2G4M27SX
• MLCC 10uF 0805 or 100uF 1206, 6.3V

Breakout PCB for Waveshare RP2040 Zero boards using GP2040 (https://gp2040-ce.info/) with joysticks using JST connectors

This board is centered around an STM32L412CB, which has a Cortex-M4 running at 80 MHz, 128K of flash, 40K of RAM, single precision FPU, USB FS Device, and a typical set of other peripherals.

The board is somewhat compatible with the STM32 Nucleo-32 boards, which are somewhat compatible with Arduino Nano. This is mainly so that I can use the Nano terminal blocks (https://www.amazon.com/gp/product/B095XVVGQ8).

The main purpose of the board is as a voltage/current logger for the study of battery charge/discharge curves. For this reason it has a large current sensing resistor connected to the L412’s op amp.

Another unique feature, for a board this size, is that it has an ETM Trace connector. This board works nicely with Segger’s J-Trace probe and Ozone debugger to provide instruction trace. The L412/L422 is the only STM32 Cortex-M4 (as far as I know) that has trace in a package smaller than 100 pins.

The KiCad schematic and pcb files are included in the download. All the parts are available from Digikey.

As of this writing I am bringing up basic software. I am also working on an update of the board to fix a couple minor bugs. I have not tried out the analog stuff yet.

I recommend Nefastor’s USB tutorial and STM32_VCP library:
https://nefastor.com/microcontrollers/stm32/usb/stm32cube-usb-device-library/usb-fundamentals/ https://github.com/Nefastor-Online/STM32_VCP

I followed the steps, wrote a little bit of my own code, and now I can use the L412’s native USB port as a virtual serial console, providing printf and getchar.

Here’s a tiny board for rumble motor

pad GND > (one of the) GND of arduino

pad 5 > pin5 of arduino board

pad VCC > VCC of arduino board

pad + > positive of rumble motor

pad - > negative of rumble motor

THANKS to Boxdgm / TinkerDadNerd / Jaybee for testing and helping me.

For REV. 2 owner

Simply wire a jumper wire from GND of arduino board to the 1 leg f trasistor.

That' all folks!