Have you ever needed an extra UART, or an extra SPI line? What about that sensor that only has one address, but you need two of them? The SAMD21 boards use what is called Sercoms (Serial Communication). The board definitions in the Arduino IDE will usually define a UART, SPI and I2C port for you, but with six Sercoms, that leaves a few extra for you to play with. Check out our new tutorial on setting up new Serial ports. We use the new Redboard Turbo to control our Serial LCD screens over custom UART, SPI and I2C buses.