The Raspberry Pi Pico's RP2040 has been embedded in a plethora of form factors, many of which feature in our list of best RP2040 boards.
SB Component's $4.50 Micro RP2040 may look familiar. It bears a striking resemblance to Solder Party's RP2040 Stamp which sees the GPIO pins broken along the perimeter of the board, but with Micro RP2040 we have an onboard USB C interface, but it came at a cost.
The sacrifice is a handful of GPIO pins. We don't get the full 40 pins from the RP2040, but that said, who uses all of them anyway? Software debug (SWD) pins are present, so you can make your own debug probe, or connect it up to an external debug probe to step through your code. The design of the board follows the Raspberry Pi Pico's castellations, which means it can be surface mount soldered, perhaps using one of the best soldering stations, into a project. The product page also claims that it can be used in a breadboard, but the bottom row of GPIO pins will have to soldered pointing upward, otherwise they will short each other out in the breadboard.
The form factor packs a lot in a small package, making it useful for creating your own USB HID devices. A version with Wi-Fi and Bluetooth would be a killer product, but you can only pack so much into the form factor.
The key difference between the Micro RP2040 and RP2040 Stamp is the USB interface. Micro features a USB C interface built in to the board, whereas Stamp required an off board USB to serial converter or an Arduino Uno shaped carrier board.
Micro RP2040 is available via SB Components for approximately $4.50. Technical details and pinout diagrams can be found in a GitHub repository.
