We are developing a custom vehicle controller that communicates via MQTT. What is the best approach to integrate our controller as a tracking device so it would send GPS location, sensor data and OBD data. We can implement any protocol behind MQTT.
The simplest way is just JSON message. Our naming scheme you can see in "flespi.io -> utils -> Message Parameters"
In addition to the dexif say, JSON message is the simplest way because then you can use a channel with mqtt protocol to feed your data into a flespi ecosystem: https://flespi.com/protocols/mqtt