Speed and Distance

[leompa]

Hello, I'm looking for speed and distance. I can get the data on my CANbus from my GPS. It provides the data in:
src addr 28 dec or 1C hex, dest addr 255, PGN 65256 - speed and direction (industry standard)

bytes 0-1 - heading, 1/128 degrees per bit (spn 165)
bytes 2-3 - speed, 1/256 kph per bit (spn 517)
bytes 4-5 - pitch, 1/128 degrees per bit -210 degrees offset (spn 583)
bytes 6-7 - altitude, 0.125 m per bit -2500 offset (spn 580)

I'd like to know if the library gets the data from these sources, since I don't have any other speed source on my CAN.

[gunicsba]

Hello @leompa I didn't find an official way to put these on the bus with our task controller.
This is often referred as "J1939 GPS speed" the way I managed to solve this is by:
isobus::CANNetworkManager::CANNetwork.send_can_message(0xFEE8, j1939_speed_data.data(), j1939_speed_data.size(), tecuCF)

I didn't check if the opposite of it is possible. But I think one would have to subscribe to the 0xFEE8 message and parse it on the fly.

Maybe best to add this in the isobus::SpeedMessagesInterface itself?

[leompa]

Perhaps it would be best to add this directly to the isobus::SpeedMessagesInterface?

I think that would be a good place to integrate it; I'll try modifying the code to see if I can read the speed from there.

[gunicsba]

I agree, that interface could try and figure out a valid speed for the ECU.

[leompa]

Hi; I saw your suggestion for improving the implementation; I think what they should add is, in addition to the 3 speed options available, a fourth one for j1939; I saw your code as you implement it in agopentaskcontrol; I'll see if I can apply something to my code to patch it now until the support is in the library.