the Raspberry Pi 4 has six SPI controllers, six I2C controllers, and six UARTs – all on its 40-pin header. You can’t make use of all of these at once, but with up to four different connections ...

The P42 Pico2 M.2 may look like an M.2 module, but it's actually a Raspberry Pi RP2350 development board in M.2 2230 form ...