Adafruit ItsyBitsy RP2040

Overview

The Adafruit ItsyBitsy RP2040 shrinks the Raspberry Pi RP2040's capabilities into a 36×18mm breadboard-friendly form factor — making it smaller than the Feather RP2040 while retaining the same dual-core performance and PIO programmable I/O. It occupies a comfortable middle ground in Adafruit's lineup: larger than a Trinket, smaller than a Feather, and perfect for projects where board size matters but pin count must not be sacrificed.

The RP2040 at the core runs two ARM Cortex-M0+ processors at 133MHz (overclockable), sharing 264KB of SRAM across six independent banks. Eight MB of SPI Flash stores programs and files. The two PIO (Programmable I/O) peripherals — each with four state machines — enable bit-bang protocols (WS2812 LEDs, I2S audio, custom serial buses) in hardware without CPU overhead. Sixteen hardware PWM channels cover servo control, LED dimming, and tone generation.

Twenty-three GPIO pins are exposed, including four 12-bit ADC inputs. All GPIO support I2C, SPI, and UART through flexible routing. A special Vhigh pin outputs the USB rail (up to 5V) for driving 5V-logic peripherals or LEDs from the regulated supply. A Digital 5 output is level-shifted to the USB voltage. An onboard RGB NeoPixel with independent 3.3V power control prevents the LED from affecting analog readings. A red LED on pin 11 serves as a traditional indicator.

The UF2 ROM bootloader enables drag-and-drop firmware updates — hold the BOOT button while connecting USB to enter mass-storage mode, then copy a .uf2 file. Both CircuitPython and MicroPython official ports are supported, as is the Raspberry Pi C/C++ SDK. Arduino support via the Mbed or earlephilhower RP2040 core is available for developers preferring the Arduino IDE.