This board connects a Pico to the GPIO header on a Pi 400, without any wires flapping in the breeze. See the schematic here (PDF).
I made this to use at work. Besides connecting power and debug, it clearly labels the Pico pinout when viewed from the top:
- Pico VSYS is powered from Pi +5V rail
- Pico SWD is connected to Pi GPIO 24/25
- Pico RUN pin is connected to a push-button
- (jumper) Pico UART on GPIO0/1 is connected to Pi GPIO14/15
- (jumper) Pico VBUS is powered from +5V rail so Pico can function as USB host
That's it, that's the whole thing. This repository is CC0-licensed, with the exception of the 3d models in the 3d/ directory.
The board is designed with KiCad nightly; if you don't have KiCad nightly installed, you can find pregenerated gerbers of the rev A PCB in the gerb/ directory, which are suitable for manufacture by JLCPCB.