RIOT/boards/feather-m0/doc.md

@defgroup boards_feather-m0 Adafruit Feather M0 @ingroup boards @brief Support for the Adafruit Feather M0.

General information

Feather M0 boards are development boards shipped by Adafruit.

All the feather M0 boards are built based on the same Atmel SAMD21G18A microcontroller. See @ref cpu_samd21.

Several types of Feather M0 boards exist:

• Feather M0 WiFi
• Feather M0 BLE
• Feather M0 Adalogger
• Feather M0 LoRa

The different modules used to differentiate the boards (ATWINC1500 WiFi, Bluefruit LE, SD card, LoRa) are connected via SPI (SPI_DEV(0)) to the SAMD21 mcu.

Pinout

AIN7 can be used to measure the voltage of a connected Lipoly battery. It is mapped to ADC_LINE(6) in RIOT.

int vbat = adc_sample(ADC_LINE(6), ADC_RES_10BIT);
vbat *= 2;      /* voltage was divided by 2, so multiply it back */
vbat *= 33;     /* reference voltage 3.3V * 10 */
vbat /= 10240;  /* resolution * 10 (because we multiplied 3.3V by 10) */
printf("Bat: %dV\n", vbat);

Flash the board

Use BOARD=feather-m0 with the make command.
Example with hello-world application:

     make BOARD=feather-m0 -C examples/basic/hello-world flash

@note If the application crashes, automatic reflashing via USB, as explained above won't be possible. In this case, the board must be set in bootloader mode by double tapping the reset button before running the flash command.

@note Adafruit changed the bootloader from the old BOSSA bootloader to the more modern UF2 bootloader around 2018. If you have a very old board, it is recommended to upgrade the bootloader to the new UF2 bootloader. Otherwise the bootloader has to be enabled by double tapping the reset button.
Upgrade instructions can be found at Adafruit: https://learn.adafruit.com/installing-circuitpython-on-samd21-boards/installing-the-uf2-bootloader

Using the WiFi interface

To enable the WiFi interface of the Feather M0 WiFi variant of the board automatically for networking applications, use feather-m0-wifi as board and define the required WiFi parameters, for example:

     CFLAGS='-DWIFI_SSID=\"<ssid>\" -DWIFI_PASS=\"<pass>\"' \
     make BOARD=feather-m0-wifi -C examples/networking/gnrc/gnrc_networking

For detailed information about the parameters, see section @ref drivers_atwinc15x0.

Using with LoRa module

To enable the LoRa module available on the Feather M0 LoRa variant of the board automatically for LoRa applications, use feather-m0-lora as board:

make BOARD=feather-m0-lora -C examples/networking/gnrc/gnrc_lorawan

For detailed information about the parameters, see section @ref drivers_sx127x.

Accessing STDIO via UART

STDIO of RIOT is directly available over the USB port.

The TERM_DELAY environment variable can be used to add a delay (in second) before opening the serial terminal. The default value is 2s which should be enough in most of the situation.