versions: diamond: read power board & front unit versions

[fouge]

uses io expander on the boards

fixes O-2189

[moritz-diller]

I suggest to read the version via the port expander only once and then save it in a static variable. See the logic for the Mainboard hardware version. Reading the version via the port expander is quite time expensive since it is accessed via I2C.

Additionally, I would not create new enums (front_unit_version_e and power_board_version_e), but add new fields to orb-messages. We should transmit the versions to orb-core anyway. This information should be logged to Datadog and we might need the Front Unit version for adjusting the RGB LED colors if we see mismatches between the different LED types.

[fouge]

@moritz-diller let's keep it simple for now:
B3 are going to be mounted with v6.2B by default so we should consider it the default plan. If we start to mount different boards on B3, then we might want to report the specific boards versions to the Jetson.

[moritz-diller]

@moritz-diller let's keep it simple for now: B3 are going to be mounted with v6.2B by default so we should consider it the default plan. If we start to mount different boards on B3, then we might want to report the specific boards versions to the Jetson.

In the long term the variant v6.2.A shall be assembled. We created v6.2.B only because we could not source the Wuerth RGB LEDs fast enough. And we should track the different versions on Datadog. Additionally the chances are quite high, that there will be further hardware changes in the future, so I recommend to create the protobuf defintion right now.

[fouge]

ah okay, I didn't understand that.
I will have to postpone to next week 👍