I’ve been experimenting with the Raspberry Pi Pico for a little while now and I found that I kept coming back to the same issues – sensors need power, servos need power, I2C devices need power and the SCL/SDA connections. While there are plenty of Ground connections, I had to make up Y-leads so that the 3v3 connections went to other devices.
I also wanted to link this board to some handy little servos, piezo elements and LEDs, as well as having a few switches and an OLED display.
A bit of tinkering with Fritzing and I ended up with this board. Actually, this is version 2. The first was missing a few connections and I’d put the switches 90 degrees around, meaning that the connections were permanently short-circuited.

I’m happy to make the files available and I’ve uploaded them to my webspace. I haven’t got my head around the whole CC-BY-SA thing, so use them. I’d love to hear from you if you have success though!
Files for the Raspberry Pi Pico circuit board:
Gerber files for the PCB are here: http://roulson.net/PiPicoPCB/Gerber.zip
STL files for the top and bottom layers of the sandwich are here: http://roulson.net/PiPicoPCB/TopSpacer.STL and here: http://roulson.net/PiPicoPCB/BottomSpacer.STL
DXF files for the top and bottom of the case are here: http://roulson.net/PiPicoPCB/TopAcrylic.DXF and here: http://roulson.net/PiPicoPCB/BottomAcrylic.DXF
You will also need a 128×64 i2c OLED display, a bunch of 0.1″ pin headers, two 5mm LEDs, four 6mm tactile push switches (with fairly long actuator around 12mm) and two 150ohm resistors. On the back is a longer pin header which is handy for a stepper motor controller or H-bridge.
Assembly
At some point I’ll do a little photo-shoot of the board being assembled. Not much to it, although some things need fitting in the right order as other parts cover up the joints.
Programming
Programming of the board seems to work really well using Microblocks, which runs either in a browser or (in my case) as a download to my Raspberry Pi 400. Microblocks is at https://microblocks.fun/
It is also possible to use BIPES or MicroPython directly with the board.