mLRS has supported DroneCAN for a while, and now that Matek has released mLRS CAN receiver devices, DroneCAN is becoming a real thing for mLRS.
Currently mLRS supports classic CAN (1 Mbps), but it is natural to consider supporting FD-CAN as well, given its higher bit rates. However, a few questions have come up, which I hope can be settled in this post.
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Is FD CAN relevant at all? We have heard comments that most DroneCAN setups nowadays use 1 Mbps, which gives us the impression that while FD-CAN certainly sounds appealing and like a must-have, it may not offer much practical value. So the simple question is: Is it actually worth bothering with FD-CAN at all?
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What bit rates would have to be supported? I assumed that 5 Mbps would be the standard go-to for FD-CAN. However, I have now seen that ArduPilot’s default is actually 4 Mbps. It also seems that much of the hardware uses CAN transceivers specified for 5 Mbps rather than 8 Mbps, and since it is recommended to stay below the limit, this may argue against 5 Mbps as a standard (is that the reason ArduPilot defaults to 4 Mbps?). To me, 2 Mbps does not seem to offer much benefit, and 3 Mbps feels a bit odd. So, I’m inclined to conclude that supporting 4 Mbps should be sufficient, without a strong need to support additional rates. Is that reasonable, or inacceptable, or should it be 5 Mbps, or what?
Many thanks in advance,
Olli