need more documentation on -fqbn param

[gherlein]

How does one construct the fqbn param?

How does one get a list of boards possible?

NOTE: this is similar to the --list-boards enhancement request earlier, but short of getting that can we at least get some examples and/or docs?

[Amertz08]

Ran into this issue too. Found the following.

https://forum.arduino.cc/index.php?topic=376923.0

I'm on Mac so for me it looks like from the root of my hardware folder /Applications/Arduino.app/Contents/Java/hardware/ I build my fqbn by looking at the folder and then the target in boards.txt so for me PATH_TO_HARDWARE/arduino/avr/boards.txt with a desired target of Arduino/Genuino Uno became arduino:avr:uno

Hope that helps and makes sense. But yeah documentation on that is lacking.

Adam

[adumont]

Indeed. My trick? Use Visual Studio Code, with the Arduino Extension. When you configure the board for sketch, it will create a new file called arduino.json under .vscode in your sketch directory, containing at least these three fields: sketch, board and configuration.

Here is an example:

{
    "sketch": "ESP-sc-gway.ino",
    "board": "esp8266:esp8266:d1_mini",
    "configuration": "CpuFrequency=80,VTable=flash,FlashSize=4M1M,LwIPVariant=v2mss536,Debug=Disabled,DebugLevel=None____,FlashErase=sdk,UploadSpeed=921600"
}

When building with VSCode, I noticed that it uses arduino-builder, and the -fqbn is esp8266:esp8266:d1_mini:CpuFrequency=80,VTable=flash,FlashSize=4M1M,LwIPVariant=v2mss536,Debug=Disabled,DebugLevel=None____,FlashErase=sdk,UploadSpeed=921600, which is the contatenation of board and configuration values.

At least that works for me :)

[jjtmp]

Ran into this issue too. Found the following.

https://forum.arduino.cc/index.php?topic=376923.0

Close. When you go to the link from @Amertz08 you get the hint to the redirect to https://arduino.github.io/arduino-cli/0.26/platform-specification/

The latter link is better than the former, I suppose. When you search for "fqbn" on the page you find even variants of providing additional details.

[per1234]

Thanks @jjtmp for sharing the link to the platform specification. There is also some information about FQBN in the FAQ:

https://arduino.github.io/arduino-cli/latest/FAQ/#whats-the-fqbn-string

arduino-builder is deprecated in favor of Arduino CLI so no further documentation will be developed specific to arduino-builder, but it would be beneficial to improve the documentation about FQBNs in general. We are using https://github.com/arduino/arduino-cli/issues/355 to track that task. I will close this issue in favor of that one. If anyone has additional information to share on the subject, feel free to comment in the other thread.