Reverse engineering the 838 commands

Coordinator
Jan 23, 2008 at 11:02 PM
I tried initializing the 838 hardware with the 84x commands, and when I attempted to switch to VPW mode, I got nothing.

Command to switch to VPW = E1 33

Got nothing useful back.

Back to the drawing board.
Coordinator
Jan 23, 2008 at 11:09 PM
Amazing what pops into one's head when they write things down. It just dawned on me, the 838 is a single protocol board, why would I have to switch to VPW?

When I feel like going back outside, I will just query the interface and see what mode it is in.

Operational mode = D0
Return for VPW = 91 07

I will see how that goes.
Coordinator
Jan 25, 2008 at 12:03 AM

shor0814 wrote:
Amazing what pops into one's head when they write things down. It just dawned on me, the 838 is a single protocol board, why would I have to switch to VPW?

When I feel like going back outside, I will just query the interface and see what mode it is in.

Operational mode = D0
Return for VPW = 91 07

I will see how that goes.


Some success!

The 838 is always in VPW mode, when issued the E1 33 command, it returns 31 E1, which indicates that E1 is an error. This is good, I assume that if E1 33 is issued to the 84x board, it returns 91 07.

I was able to query VIN and RPM, I will decode the values tonight to verify. I do know the RPM returned 0, because the engine was off. I wanted to try with the engine off, but had trouble with my little test program not releasing the serial port. That can be for another day.