How to use SAMD21 M0 boards with OS Linux
If you Linux user this instruction help to you, for upload Arduino sketch to SAMD21 M0 boards.
Please refer to the preparation in advance：https://www.arduino.cc/en/Guide/Linux
Step 1: Virtual Machine connects to SAMD21M0
Please check when Popup shows up: Remember my choice and do not ask again.
Step 2：Create sketch, select board type and port number to upload
If board type doesn’t have Arduino M0，please turn to Broad Manager and download it.
Step 3: after 4 times warning:*****timeout，then Uploading… changed Done Uploading
Step 4: Using Serial Port Monitor to View Program Running
Changed the port number to CH340G(/ttyUSB0 in my Linux)
Use the Serial adapter (CH340/CP2104/FT232) connect to Pin of TXD RXD On SAMD21 M0
In the end - BLINK is OK and the program is print what I edit.