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Atmel SAM D21 Xplained Pro

Support for the Atmel SAM D21 Xplained Pro board. More...

Detailed Description

Support for the Atmel SAM D21 Xplained Pro board.


The SAMD21 Xplained Pro is an ultra-low power evaluation board by Atmel featuring an ATSAMD21J18A SoC. The SoC includes a SAMD21 ARM Cortex-M0+ micro- controller. For programming the MCU comes with 32Kb of RAM and 256Kb of flash memory.

The samd21-xpro is available from various hardware vendors for ~30USD (as of 2017 May).


samd21-xpro image


Family ARM Cortex-M0+
Vendor Atmel
RAM 32Kb
Flash 256Kb
Frequency up to 48MHz
FPU no
Timers 5 (16-bit)
ADCs 1x 12-bit (20 channels)
UARTs max 6 (shared with SPI and I2C)
SPIs max 6 (see UART)
I2Cs max 6 (see UART)
Vcc 1.62V - 3.63V
Datasheet Datasheet
Board Manual Board Manual

User Interface

1 User button and 1 LED:

Device PIN
SW0 (button) PA15

Implementation Status

Device ID Supported Comments
MCU samd21 yes
Low-level driver GPIO yes
ADC yes
PWM yes
UART yes
I2C yes
SPI yes
USB yes
RTT yes
RTC yes
Timer yes

Flashing the device

Connect the device to your Micro-USB cable using the port labeled as DEBUG USB.

The standard method for flashing RIOT to the samd21-xpro is using edbg. by calling: make BOARD=samd21-xpro -C tests/leds flash

Note that on Linux, you will need libudev-dev package to be installed.

Users can also use openOCD to flash and/or debug the board using: PROGRAMMER=openocd make BOARD=samd21-xpro -C tests/leds flash

On Linux you will have to add a udev rule for hidraw, like

echo 'KERNEL=="hidraw*", SUBSYSTEM=="hidraw", MODE="0664", GROUP="plugdev"' \
| sudo tee -a /etc/udev/rules.d/99-usb.rules
sudo service udev restart

Arch Linux

With yaourt:

yaourt -S libudev0
yaourt -S hidapi-git
yaourt -S openocd-git
# edit PKGBUILD, add "cmsis-dap hidapi-libusb" to "_features"


Although this refers to setting up the SAMR21, this guide is still very helpful to understanding how to set up a solid RIOT development environment for the SAMD21: http://watr.li/samr21-dev-setup-ubuntu.html

Known Issues / Problems


file  board.h
 Board specific definitions for the Atmel SAM D21 Xplained Pro board.
file  gpio_params.h
 Board specific configuration of direct mapped GPIOs.
file  periph_conf.h
 Configuration of CPU peripherals for the Atmel SAM D21 Xplained Pro board.