Michael, the obdii command's broadcast feature isn't capable of processing multiple responses, maybe that's what happens. It's more meant as a ping to see if there are some SAE conforming devices on the bus. Don't expect to detect specialized devices by a broadcast, only some devices acting in the standard SAE/OBDII ID range (7E0-7E7) will listen to the broadcast ID. To find ISO-TP devices not conforming to the SAE ID range, you need to loop over the probable TX ID range, e.g. 500-7FF (make sure there are no process data frames present in that range first). Looping over an ID range is currently best done using a script, the re scan tool lacks this option. Most EV do not implement standard SAE OBDII PIDs, so querying the VIN by 0902 normally doesn't work (see other vehicle modules for some examples). Most EV don't even comply to the OBDII standard of giving you bitsets of supported PIDs. But as you see a response, try sending the request to the device the response corresponds to (i.e. response ID - 8). The VIN should normally be on device 7E0 7E8. It's also totally normal the devices only respond while the car is on, awake or charging. Finding out how to wake up a car from OBD is one of the hard parts. Finally, if the vehicle currently loaded doesn't implement a full shutdown (happens when switching to another vehicle like NONE), you may end up with partially initialized CAN interfaces or other strange issues. To make sure the vehicle module doesn't interfere with your scans, boot into vehicle NONE. Regards, Michael Am 20.09.22 um 08:26 schrieb Michael Geddes:
Hi all, I have got my OVMS device (no SIM yet, but I'm working on that), and have been connecting and playing round with commands.
I'm starting to get my head around things. I have being mucking round with SavvyCan and now understand a little the ISO-TP protocol stuff happening on top of the standard can bus now. SavvyCan seems to like disconnecting from the TCP server, but going via a COM emulator seems to work better (and can be restarted). All very weird, but I can cope with that.
I'm getting a weird response from the following when it responds (VIN): obdii can1 request broadcast 0902
It contains elements of my actual VIN but not the main number at the end. I'm wondering if this is an OBDII receive issue? Does this command work for other people to get the actual VIN? Also it seems to only work in certain circumstances (?when the car is on?).. which is "fun".
I have also had issues where if I use the "Set Car to NONE" on the RE PID Scanner interface, it seems to stop communications.. and obdiicommand set no longer works - even if I restart the CAN bus. Setting the vehicle back to 'KO' seems to fix things.
//.ichael Geddes
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