Use pin change interrupts for full configurability of serial port pins · Issue #9 · PaulStoffregen/AltSoftSerial · GitHub
![SAMD21 Mini Breakout DEV-13664: Possible to use SERCOMs to create a serial on D9 (TX) and D8 (RX)? - SparkFun Electronics Forum SAMD21 Mini Breakout DEV-13664: Possible to use SERCOMs to create a serial on D9 (TX) and D8 (RX)? - SparkFun Electronics Forum](https://media.digikey.com/Photos/RDL/DEV-13664%20-%20Pinout.png)
SAMD21 Mini Breakout DEV-13664: Possible to use SERCOMs to create a serial on D9 (TX) and D8 (RX)? - SparkFun Electronics Forum
Arduino Project: iPhone to HM-10 BLE to NB-IoT Shield to NB-IoT Network to Internet to Linux Server - Makers (DIY) - Unix Linux Community
![SoftwareSerial has an alternative AltSoftSerial - Networking, Protocols, and Devices - Arduino Forum SoftwareSerial has an alternative AltSoftSerial - Networking, Protocols, and Devices - Arduino Forum](https://europe1.discourse-cdn.com/arduino/original/4X/a/3/0/a30b13f7f1fd5a292baa4837b22ec9d1b0fda59f.png)