Speedometer HUD is a relative simple project than navigation HUD. The initial idea is a speedometer HUD and can fix speed error by GPS, but I think the project can split to two parts:
- Arduino (CanBus)
- Android (GPS)
The 1st and simple part: Arduino (CanBUS), it's speedometer HUD.
The 2nd part need use arduino to communicate to any android phone, fetch android's GPS speed.
Combine 1st & 2nd part, we can correct CanBus speed error by GPS, but the benefit is not obvious, so I stop developing 2nd part.
Speedometer HUD had two module:
- CanBUS parser
- GarminHUD controller
Fortunately, GarminHUD has been hacked:
https://hackaday.com/2014/03/30/controlling-the-garmin-hud-with-bluetooth/
https://github.com/gabonator/Work-in-progress/tree/master/GarminHud
So my remain job is parsing CanBUS, and calling the library to control GarminHUD, done!