# Adafruit Feather M4 CAN Express

> CAN-bus-capable Feather with ATSAME51J19 ARM Cortex-M4F @ 120MHz, built-in CAN transceiver + 5V booster, USB-C, 21 GPIO, 2MB SPI Flash, dual DAC, and LiPo charging. Ideal for automotive and industrial CAN Bus projects.

## Quick Facts

- **Brand:** Adafruit
- **Board Type:** microcontroller-board
- **Price:** ~$24.95
- **Product Readiness:** consumer
- **CPU:** ARM Cortex-M4F @ 120MHz (ATSAME51J19)
- **CPU Architecture:** ARM Cortex-M4F
- **CPU Cores:** 1
- **RAM:** 192KB
- **Flash:** 512KB + 2MB SPI Flash
- **Power:** 5V via USB-C or LiPoly battery
- **Operating Voltage:** 3.3V
- **Dimensions:** 50.8 x 22.8 x 7mm
- **Weight:** 5g
- **Antenna:** none

## Connectivity

- **Wifi:** false
- **Bluetooth:** false
- **Zigbee:** false
- **Ethernet:** false

## Open Source

- **Firmware:** Yes
- **Schematics:** Yes
- **PCB Layout:** Yes

## Certifications

RoHS

## Compatible Firmware

circuitpython, arduino

## Use Cases

- industrial-automation
- iot
- field-data-logger

## Components

- **ATSAME51J19** (mcu): Microchip ATSAME51J19 ARM Cortex-M4F @ 120MHz, 512KB Flash, 192KB RAM, native CAN 2.0, USB. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fww1.microchip.com%2Fdownloads%2Fen%2FDeviceDoc%2FSAM_E51_Family_Data_Sheet_DS60001525C.pdf&ref=openhardware.directory&product=adafruit-feather-m4-can-express&source=md-export)

## Protocols

- **I2C**: SDA: PA22, SCL: PA23
- **SPI**: MOSI: PA23, MISO: PA22, SCK: PA17
- **UART**: TX: PB22, RX: PB23
- **I2S**: 
- **CAN**: TX: CANTX, RX: CANRX
- **USB**: 
- **PWM**: 
- **ADC**: 
- **DAC**: DAC0: A0, DAC1: A1

## GPIO Map

| Pin | Name | Type | Functions |
|-----|------|------|-----------|
| A0 | A0 — ADC/DAC0 (PA02) | ADC | analog-input, dac, digital-input, digital-output |
| A1 | A1 — ADC/DAC1 (PA05) | ADC | analog-input, dac, digital-input, digital-output |
| A2 | A2 — ADC (PB08) | ADC | analog-input, digital-input, digital-output |
| A3 | A3 — ADC (PB09) | ADC | analog-input, digital-input, digital-output |
| A4 | A4 — ADC (PA04) | ADC | analog-input, digital-input, digital-output |
| A5 | A5 — ADC (PB02) | ADC | analog-input, digital-input, digital-output |
| D4 | D4 — Digital | — | digital-input, digital-output |
| D5 | D5 — Digital/PWM (PA16) | — | digital-input, digital-output, pwm |
| D6 | D6 — Digital/PWM (PA18) | — | digital-input, digital-output, pwm |
| D9 | D9 — Digital/PWM (PB03) | — | digital-input, digital-output, pwm |
| D10 | D10 — Digital/PWM/CS (PA20) | SPI | digital-input, digital-output, pwm, spi-cs |
| D11 | D11 — MOSI (PA23) | SPI | digital-input, digital-output, pwm, spi-mosi |
| D12 | D12 — MISO (PA22) | SPI | digital-input, digital-output, spi-miso |
| D13 | D13 — SCK/LED (PA17) | SPI | digital-input, digital-output, spi-sck |
| SDA | SDA — I2C Data (PA12) | I2C | digital-input, digital-output, i2c-sda |
| SCL | SCL — I2C Clock (PA13) | I2C | digital-input, digital-output, i2c-scl |
| RX | RX — UART (PB23) | UART | digital-input, digital-output, uart-rx |
| TX | TX — UART (PB22) | UART | digital-input, digital-output, uart-tx |
| CANTX | CAN TX | CAN | can-tx |
| CANRX | CAN RX | CAN | can-rx |

## Available Software

- **[circuitpython]()** (open-source)
- **[arduino]()** (open-source)

## Description

## Overview

The Adafruit Feather M4 CAN Express brings native CAN bus connectivity to the Feather form factor for the first time. It is built around the Microchip ATSAME51J19 — an ARM Cortex-M4F running at 120MHz with a built-in CAN controller — and adds an onboard CAN transceiver and 5V booster circuit to drive the CAN bus directly without any external components. A screw terminal block provides the CAN H/L connection points, making integration into automotive and industrial networks straightforward.

The SAME51 differentiates itself from the SAMD51 used in other Adafruit Feathers by adding native CAN 2.0 support (both standard 11-bit and extended 29-bit frame formats) directly in silicon. Beyond CAN, the chip provides six hardware SERCOM modules configurable as SPI, I2C, or UART, plus I2S input and output, dual 12-bit DAC, and dual 12-bit ADC. The Feather M4 CAN adds 2MB of external SPI Flash for additional code and data storage.

Power management follows the standard Feather specification: USB-C for power and data, a built-in 100mA LiPoly charger, and a 3.3V regulator delivering up to 500mA peak. A 32.768 kHz crystal supports a real-time clock. An onboard mini NeoPixel provides visual status. The 5V CAN booster is generated internally so even USB-powered (5V) operation supports proper CAN signaling levels.

The board is programmed via the pre-loaded UF2 bootloader supporting both CircuitPython (with the canio module for CAN frame sending/receiving) and the Arduino IDE. Adafruit publishes a dedicated guide covering canio usage for automotive data logging, CAN-based motor controllers, and sensor networks.

## Where to Buy

- [Adafruit](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F4759&ref=openhardware.directory&product=adafruit-feather-m4-can-express&source=md-export) — 24.95

## Resources

- [product page](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F4759&ref=openhardware.directory&product=adafruit-feather-m4-can-express&source=md-export)
- [product](https://openhardware.directory/r?to=https%3A%2F%2Fwww.adafruit.com%2Fproduct%2F4759&ref=openhardware.directory&product=adafruit-feather-m4-can-express&source=md-export)
- [documentation](https://openhardware.directory/r?to=https%3A%2F%2Flearn.adafruit.com%2Fadafruit-feather-m4-can-express&ref=openhardware.directory&product=adafruit-feather-m4-can-express&source=md-export)
- [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2Fadafruit%2FAdafruit_SAME51_CAN&ref=openhardware.directory&product=adafruit-feather-m4-can-express&source=md-export)

## Tags

`feather`, `atsame51`, `can-bus`, `circuitpython`, `adafruit`, `usb-c`, `automotive`, `industrial`

## Images

![Adafruit Feather M4 CAN Express](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m4-can-express/5f1cf205f0cb.jpg)
![Adafruit Feather M4 CAN Express](https://nbg1.your-objectstorage.com/openhardware-directory/entities/adafruit-feather-m4-can-express/2a08985844ac.jpg)

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