I never was much of a fan of the Raspberry Pi, but I really like the little Pico.
"Pico" is sort of a nickname for the little RP2040 single board computer that you can buy for $4 these days. Pico is the board and RP2040 is the chip on the board.
The chip itself sells for $1, but that is entirely academic for most people.
It has a dual core ARM Cortex M0+ running at 133 Mhz, along with 264k of internal ram and 2M bytes of off-chip flash. The board has a button labeled "bootsel" and the usual micro USB connector. No reset button sad to say, but you do get an onboard LED.
Tom's electronics pages / email@example.com