# Adafruit ItsyBitsy M4 Express > High-performance compact board with ATSAMD51 Cortex M4F at 120MHz, 192KB RAM, 512KB flash, 2MB SPI flash, dual 12-bit DAC/ADC, 18 PWM outputs, AES-256 crypto, and native USB. Measures 36mm × 18mm. ## Quick Facts - **Brand:** Adafruit - **Board Type:** dev-board - **Price:** ~$14.95 - **Product Readiness:** consumer - **CPU:** Microchip ATSAMD51 ARM Cortex M4F - **CPU Architecture:** ARM Cortex-M4F - **CPU Cores:** 1 - **RAM:** 192 KB - **Flash:** 512 KB - **Power:** 5V via Micro USB or LiPo battery via JST connector - **Operating Voltage:** 3.3V - **Dimensions:** 35.9mm × 17.8mm × 4.2mm - **Weight:** 2.4g ## Open Source - **Firmware:** Yes - **Schematics:** Yes - **PCB Layout:** Yes ## Compatible Firmware circuitpython, arduino ## Use Cases - audio-synthesis - high-speed-dsp - usb-hid - education - compact-controller - prototyping ## Components - **ATSAMD51** (mcu): 32-bit ARM Cortex M4F at 120 MHz with 512 KB flash, 192 KB SRAM, AES-256, TRNG, native USB. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fww1.microchip.com%2Fdownloads%2Fen%2FDeviceDoc%2FSAM_D5xE5x_Family_Data_Sheet_DS60001507G.pdf&ref=openhardware.directory&product=adafruit-itsybitsy-m4-express&source=md-export) - **GD25Q16C** (flash): 2 MB SPI NOR flash for CircuitPython code, accessible as USB drive. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.gigadevice.com%2Fdatasheet%2Fgd25q16c%2F&ref=openhardware.directory&product=adafruit-itsybitsy-m4-express&source=md-export) - **APA102 DotStar** (led): Built-in RGB DotStar LED for status and animations. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fcdn-shop.adafruit.com%2Fproduct-files%2F2343%2FSK9822_FINAL.pdf&ref=openhardware.directory&product=adafruit-itsybitsy-m4-express&source=md-export) ## Protocols - **I2C**: SDA: D14, SCL: D15 - **SPI**: MOSI: D11, MISO: D12, SCK: D13, SS: D10 - **UART**: TX: D0, RX: D1 - **USB**: - **I2S**: ## GPIO Map | Pin | Name | Type | Functions | |-----|------|------|-----------| | D0 | TX | UART | digital-input, digital-output | | D1 | RX | UART | digital-input, digital-output | | D2 | GPIO | — | digital-input, digital-output | | D3 | GPIO | — | digital-input, digital-output, pwm | | D4 | GPIO | — | digital-input, digital-output | | D5 | GPIO | — | digital-input, digital-output, pwm | | D7 | GPIO | — | digital-input, digital-output | | D9 | GPIO | — | digital-input, digital-output, pwm | | D10 | SS | SPI | digital-input, digital-output, pwm | | D11 | MOSI | SPI | digital-input, digital-output, pwm | | D12 | MISO | SPI | digital-input, digital-output | | D13 | SCK | SPI | digital-input, digital-output | | D14 | SDA | I2C | digital-input, digital-output | | D15 | SCL | I2C | digital-input, digital-output | | A0 | ADC/DAC | — | digital-input, digital-output, analog-input, dac | | A1 | ADC/DAC | — | digital-input, digital-output, analog-input, dac | | A2 | ADC | — | digital-input, digital-output, analog-input | | A3 | ADC | — | digital-input, digital-output, analog-input | | A4 | ADC | — | digital-input, digital-output, analog-input | | A5 | ADC | — | digital-input, digital-output, analog-input | ## Available Software - **[CircuitPython]()** (open-source) - **[Arduino]()** (open-source) ## Description ## 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. ## Where to Buy - [Adafruit](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F3800&ref=openhardware.directory&product=adafruit-itsybitsy-m4-express&source=md-export) — 14.95 ## Resources - [product page](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F3800&ref=openhardware.directory&product=adafruit-itsybitsy-m4-express&source=md-export) - [product](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F3800&ref=openhardware.directory&product=adafruit-itsybitsy-m4-express&source=md-export) - [documentation](https://openhardware.directory/r?to=https%3A%2F%2Flearn.adafruit.com%2Fintroducing-adafruit-itsybitsy-m4&ref=openhardware.directory&product=adafruit-itsybitsy-m4-express&source=md-export) - [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2Fadafruit%2FAdafruit-ItsyBitsy-M4-Express-PCB&ref=openhardware.directory&product=adafruit-itsybitsy-m4-express&source=md-export) ## Tags `circuitpython`, `arduino`, `atsamd51`, `cortex-m4`, `adafruit`, `itsybitsy`, `express`, `compact`, `high-performance`, `dac` ## Images ![Adafruit ItsyBitsy M4 Express](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-itsybitsy-m4-express/b9d42aaa4945.jpg) ![Adafruit ItsyBitsy M4 Express](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-itsybitsy-m4-express/159988c06193.jpg) --- [View full device page](https://openhardware.directory/devices/adafruit-itsybitsy-m4-express)