Wed 12 October 2016 By In. Tags: Some AVR devices, like attiny85 (on Adafruit, for example), do not have hardware UART. However, it would be still nice to have serial output from them. I wrote a simple SoftSerial package, which can use any GPIO pin as TX UART pin.
To upload to your Gemma or Trinket: 1) Select the proper board from the. SoftwareSerial - the built in SoftSerial library can (at least) transmit data on any. I want to use SoftwareSerial with my ATTiny85 and when I google it several. I am designing a low-power RF application using an ATTiny (Adafruit Trinket).