Adafruit Metro M4 Express AirLift

The Adafruit Metro M4 Express AirLift is an ARM development board based on the Atmel ATSAMD51J19 family of SoC that has Arduino shield compatible form factor, and a built-in EspressIf ESP32 Wi-Fi Co processor.

Interfaces

Interface Hardware Supported TinyGo Support
GPIO YES YES
UART YES YES
SPI YES YES
I2C YES YES
ADC YES YES
PWM YES YES
USBDevice YES YES

Pins

Pin Hardware pin Alternative names
D0 PA23 UART_RX_PIN
D1 PA22 UART_TX_PIN
D2 PB17
D3 PB16
D4 PB13
D5 PB14
D6 PB15
D7 PB12
D8 PA21
D9 PA20
D10 PA18
D11 PA19 SPI1_SDO_PIN
D12 PA17 SPI1_SCK_PIN
D13 PA16 LED, SPI1_SDI_PIN
D40 PB22 WS2812
A0 PA02
A1 PA05
A2 PB06
A3 PB00
A4 PB08
A5 PB09
USBCDC_DM_PIN PA24
USBCDC_DP_PIN PA25
UART2_TX_PIN PA04 NINA_TX
UART2_RX_PIN PA07 NINA_RX
NINA_CS PA15
NINA_ACK PB04
NINA_GPIO0 PB01
NINA_RESETN PB05
NINA_RTS PB23
SDA_PIN PB02
SCL_PIN PB03
SPI0_SCK_PIN PA13 NINA_SCK
SPI0_SDO_PIN PA12 NINA_SDO
SPI0_SDI_PIN PA14 NINA_SDI
QSPI_SCK PB10
QSPI_CS PB11
QSPI_DATA0 PA08
QSPI_DATA1 PA09
QSPI_DATA2 PA10
QSPI_DATA3 PA11

Machine Package Docs

Documentation for the machine package for the Adafruit Metro M4 Airlift

Flashing

UF2

The Metro M4 Express comes with the UF2 bootloader already installed.

CLI Flashing

  • Plug your Metro M4 Express into your computer’s USB port.

  • Flash your TinyGo program to the board using this command:

    tinygo flash -target=metro-m4-airlift [PATH TO YOUR PROGRAM]
    
  • The Metro M4 Express board should restart and then begin running your program.

Troubleshooting

If you have troubles getting your Metro M4 Express board to receive code, try this:

  • Press the “RESET” button on the board two times to get the Metro M4 Express board ready to receive code.

  • The Metro M4 Express board will appear to your computer like a USB drive.

  • Now try running the command as above:

    tinygo flash -target=metro-m4-airlift [PATH TO YOUR PROGRAM]
    

Once you have updated your Metro M4 Express board the first time, after that you should be able to flash it entirely from the command line.

Notes

You can use the USB port to the Metro M4 Express as a serial port. UART0 refers to this connection.

The Neopixel LED on the Metro M4 Express can be accessed using the WS2812 driver via the PB22 pin