Using ATSAMD21 SERCOM for more SPI, I2C and Serial ports

Official Hardware Classic Zero
1

I found this really helpful instructions from adafruit:
--> Overview | Using ATSAMD21 SERCOM for more SPI, I2C and Serial ports | Adafruit Learning System

2

Thanks Dirk67. That's a really useful article for anyone who requires additional serial, SPI or I2C ports for their project.