393fe8e449
As found in 6f2b39c1be6a8b9531264d92138dc2629d51cfa0, you can't just register a control callback by itself, you can only register them in the set config callback, (or, at least, _after_ set config has been done. This has been compile tested only for the extra examples that were found to have this failing pattern.
Examples in these directories are not only for the board listed, they are simply preconfigured for those boards. If you do not find an example of the peripheral you want to use listed for your board, please look at the other boards. The differences between boards for the examples is normally only LEDs and buttons on different pins, and different memory sizes.