Microcontroller reference

Initialise the .ino file (thought of as a C file with additional arduino libraries):

arduino-cli config init

The .ino file created can be modified. For example, to create a blinking LED programme:

void setup() {
    pinMode(LED_BUILTIN, OUTPUT);
}

void loop() {
    digitalWrite(LED_BUILTIN, HIGH);
    delay(1000);
    digitalWrite(LED_BUILTIN, LOW);
    delay(1000);
}

The programme must be compiled, then uploaded to the microcontroller. First install the libraries for the microcontroller

sudo arduino-cli core install arduino:avr

For the freenova microcontroller, the bash commands are:

sudo arduino-cli compile --fqbn arduino:avr:uno MyFirstSketch
sudo arduino-cli core install arduino:avr
sudo arduino-cli upload -p /dev/ttyUSB0 --fqbn arduino:avr:uno MyFirstSketch

An excellent tutorial for programmes one could write for the Arduino can be found on the Freenova Github repository.