Adafruit ItsyBitsy M4 Express

Overview

The Adafruit ItsyBitsy M4 Express brings the performance of the ATSAMD51 ARM Cortex M4F processor to the ultra-compact ItsyBitsy form factor, running at 120 MHz with hardware floating-point, 192 KB of SRAM, and 512 KB of internal flash. This represents a significant performance leap over the M0-based ItsyBitsy, suitable for audio processing, DSP, real-time control, and complex CircuitPython scripts.

Twenty-three GPIO pins are provided with 7 analog inputs, 18 PWM outputs, 6 hardware SERCOM interfaces (configurable as SPI, I2C, or Serial), dual 1 MSPS 12-bit DAC outputs on A0 and A1, and dual 1 MSPS 12-bit ADC. On-chip AES-256 hardware acceleration and a true random number generator (TRNG) provide cryptographic capability without software overhead. An 8-bit parallel capture interface and I2S audio are also available.

The 2MB SPI flash is accessed as a USB drive under CircuitPython, enabling code editing via any text editor on any OS. An RGB DotStar LED and a red LED on pin 13 are included. The board can drive over 60,000 NeoPixel LEDs via DMA — useful for large LED installations. Native USB HID, MIDI, CDC serial, and mass storage are all supported.

At 36mm × 18mm and 2.4g, the ItsyBitsy M4 Express is the highest-performance compact CircuitPython board in Adafruit's lineup, making it a compelling choice for audio synthesis, machine vision preprocessing, high-speed data acquisition, and any application requiring more than the M0 can provide in a small package.