[Ovmsdev] 40kwh leaf

[Robin O'Leary]

On Mon, Sep 23, 2019 at 10:59:44AM +0100, Glyn Hudson wrote:
> In a couple of weeks time I will have on lone for a week a 40kwh 2018 leaf.
> I briefly tested ovms on the 40kwh leaf a while back but no metrics seems
> to be supported.
>
> I'll do my best in this time to try and figure out what's different between
> the older and newer model of the leaf to work towards adding support.

The OBD port in the new LEAF is now behind a gateway, so it no longer
hears any passive CAN traffic.  We largely depend on passive traffic
at the moment, only making a few active queries for odd things we can't
get otherwise (mostly detailed battery stuff).  The new way would have
to be a radical redesign, making active queries for everything.

> Does anyone know if the 40kwh leaf CAN frames has been decoded? If so is
> this documented anywhere?

When I had a 40KWh LEAF for a day, I did get logs of all the active
queries I already knew about, and do a few experiments.  I haven't checked
everything in detail, but they do seem to be mostly the same as before.

I also found a couple of new modules and UDS queries, but didn't have time
to investigate more deeply what they do.

> There must be some major changes since not even a
> single metric seemed to work when I tested briefly.

The OVMS LEAF code currently depends on hearing some specific passive
traffic before doing any active stuff (to ensure that the active queries
don't keep the car awake), so we would first need to remove that check.

> What would be the most useful data I could capture during my time with the
> new leaf?

It would be useful just to have more logs of the known active
queries, to confirm that they work the same as before.
I only logged straightforward driving, so it would be good to capture more
exotic activities like rapid charging, slow charging, using timers, etc.

With a bit more time to play, we could perhaps do some exhaustive scans
of all module-IDs and all UDS sub-IDs.

> It would be great to be able to add ovms support the new leaf.

I have been thinking the best way to do that.  It might get quite messy
to support both primarily-passive and primarily-active styles in the
same code, so I have been wondering if it might be better to start a
new LEAF vehicle type that is entirely driven by active queries.

In the longer term, assuming active queries mostly work the same way on
old and new models, it might be that the active style gets good enough
to replace the passive style for older models too.