When Raspberry Pi co-founder Eben Upton announced via Twitter that Raspberry Pi had an informal RP2040 sample program, many makers pitched their ideas for the chip that powers the Raspberry Pi Pico. One of those makers, arturo182, has already started work on an RP2040 based Raspberry Pi Zero W form factor board, but for its next project it has tweeted the design process of a one-inch square RP2040 board that packs plenty of features into a tiny package.
I think I managed to squeeze in a lot of functionality into a square inch:- @Raspberry_Pi RP2040 (duh ;)- USB broken out- SWD broken out- All 30 GPIOs broken out- 600mA 3.3V LDO- 16MB FLASH- Reset Button- LiPo supply and charging circuit (with charging LED)- A Neopixel pic.twitter.com/1axuSN871nApril 7, 2021
Arturo182 has designed the one-inch square RP2040 Stamp, and they have documented the entire process via an extensive Twitter thread. The idea behind the board is to pack all of the functionality of the Raspberry Pi Pico into a package that can be soldered into a project. There are no fiddly surface mount components to worry about, just all of the pins you need and castellations for easy soldering.
Arturo182 has fabricated a small number of test boards, and they have managed to pack in extra features. As well as the full Raspberry Pi Pico GPIO, we see a large 16MB flash, a reset button, LiPo battery charging circuit, and of course a Neopixel RGB LED.
The GPIO is broken out around the board's perimeter, and we see that artuto182 has considered the pin numbering scheme, favoring a logical progression counter-clockwise around the board with pin numbers printed at each corner. You will notice that there is no USB interface but fear not, as there are GPIO pins for both USB and SWD debugging.
The RP2040 Stamp project is still a work in progress, but you can learn more via the Solder Party Twitter account.