Raspberry Pi Pico

"The main chip on board is the 'RP2040' made by Raspberry Pi (their first in-house microcontroller chip!) and is a dual-core ARM Cortex M0 processor, with a flexible clock running up to 133MHz. RP2040 microcontroller chip designed by Raspberry Pi in the United Kingdom Dual-core ARM Cortex M0 processor, flexible clock running up to 133 MHz 264kB of SRAM, and 2MB of onboard Flash memory Castellated module allows soldering directly to carrier boards (non-header version only) USB 1.1 Host and Device support Low-power sleep and dormant modes Drag & drop programming using mass storage over USB 26 multi-function GPIO pins 2×SPI, 2×I2C, 2×UART, 3×12-bit ADC, 16×controllable PWM channels Real-time clock (RTC) Temperature sensor Accelerated floating-point libraries on-chip 8×Programmable IO (PIO) state machines for custom peripheral support Dimensions: 51mm x 21mm"