Q: how can one pass ConfigOptions for the compilation?

[4ntoine]

Bug Report

Background

Boards can provide ConfigOptions describing the board. For instance, "Nano" (arduino:avr:nano) provides 3 options (328, 328old and 168) based on the cpu and bootloader. Some arguments might make sense for the compilation, eg. cpu frequency.

Current behavior

There is no config option argument to pass (or it's unclear to me on how to do it).
There are some "custom build properties", but it's unclear if it's what i mean.

Expected behavior

There is a way to pass a ConfigOption value and it's documented.

Environment

• CLI version (output of arduino-cli version): 0.20.2
• OS and platform: any

Additional context

[per1234]

Hi @4ntoine. These custom board option are specified as part of the FQBN.

This is documented in the platform specification:

https://arduino.github.io/arduino-cli/dev/platform-specification/#custom-board-options

and the FAQ:

https://arduino.github.io/arduino-cli/dev/FAQ/#how-to-set-multiple-board-options

So if you wanted to specify the atmega168 option ID for the arduino:avr:nano board's processor menu ID, the FQBN would be:

arduino:avr:nano:processor=atmega168

You can specify values for as many menu IDs as you like via a comma-separated list.

We are using this issue to track need to communicate better about what FQBN is and how it works: #355

[4ntoine]

@per1234 Thank you