Blinks an LED. The "Hello, World" of things. $ tinygo flash -target arduino-uno-q -size short ./blinky code data bss | flash ram 6004 1452 4328 | 7456 5780 /tmp ...

This is a fork of the code and examples from "Make: AVR Programming" that I've addapted to work with the Arduino Uno R3 (I'm using the SMD variant, but it shouldn't matter which UNO R3 you're using).