@defgroup boards_adafruit-metro-m4-express Adafruit Metro M4 Express @ingroup boards @brief Support for the Adafruit Metro M4 Express

General information

@image html https://cdn-learn.adafruit.com/assets/assets/000/085/521/large1024/adafruit_products_metro-m4-top.jpg "Picture of the Adafruit Metro M4 Express"

The main features of the board are:

ATSAMD51 Cortex M4 running at 120 MHz
Hardware DSP and floating point support
512 MiB Flash
192 KiB KiB RAM
external 2 MiB QSPI Flash storage
WS281x RGB LED (NeoPixel)
32-bit, 3.3V logic and power
native USB

Pinout

@image html https://cdn-learn.adafruit.com/assets/assets/000/111/183/original/adafruit_products_Adafruit_Metro_M4_Express_Pinout.png "Official Pinout of the Metro M4 Express" width=100%

Schematics

@image html https://cdn-learn.adafruit.com/assets/assets/000/053/093/original/adafruit_products_schem.png "Original Board Schematics"

Arduino Compatibility

The board is compatible with Shields for the Arduino UNO / Arduino Zero.

@warning The SPI bus on D11/D12/D13 is only available when periph_uart is not used, as this pins are connected to the same SERCOM peripheral. This is board design flaw that we cannot work around unless resorting to desperate means such as bit-banging either the SPI bus or the UART interface.

Flash the board

The board is flashed using its on-board boot loader.

The process is automated in the usual make flash target.

If RIOT is already running on the board, it will automatically reset the CPU and enter the bootloader. If some other firmware is running or RIOT crashed, you need to enter the bootloader manually by double tapping the board's reset button.

Readiness of the bootloader is indicated by LED pulsing in red.

@note You may need to pass MOST_RECENT_PORT=0 and manually pass the PORT if you enter the bootloader by hand.

Accessing STDIO

The usual way to obtain a console on this board is using an emulated USB serial port.

Doc