SAMD21

RobotDyn

• https://robotdyn.com/samd21-m0.html
• https://robotdyn.com/pub/media/0G-00005517==SAMD21-M0/DOCS/DIM==0G-00005517==SAMD21-M0.pdf
• https://robotdyn.com/pub/media/0G-00005517==SAMD21-M0/DOCS/PINOUT==0G-00005517==SAMD21-M0.pdf
• https://robotdyn.com/pub/media/0G-00005517==SAMD21-M0/DOCS/Schematic==0G-00005517==SAMD21-M0.pdf
• http://www.armlearning.com/hardware/robotdyn-samd21-m0-arduino-compatible-board.php
• https://robotdyn.com/info/how-to-use-samd21-m0-boards-with-os-linux.html

"Wemos" version

These seem to be RobotDyn clones. The difference is that they are using the Arduino Zero bootloader, instead of the Arduino M0 bootloader that the RobotDyn products come with.

• https://startingelectronics.org/articles/arduino/wemos-arduino-m0/
• https://blog.startingelectronics.com/wemos-samd21-m0-arduino-m0-compatible-board/