My findings on the CAN bus

I just charged to 80% for the first time. This charged to an SOC of 85.2. I thought for sure it would be closer to 80% than the carwings indicated 83%, not higher than 83%..

Perhaps display SOC (0 to 99.9) or SOC/4 (0 to 25.0) or kWh (00.0 to 24.0).

Then show 23.9 as 23:09 or some such?

The problem is the hours only go up to 30 something, and the minutes only go up to 59. So theres no way to show a number like 67 no matter where you place it in the clock display..

That is why I suggested showing SOC scaled as "kWh remaining", 0 to 24, instead percent (0 to 100).

turbo2ltr said:

The problem is the hours only go up to 30 something, and the minutes only go up to 59. So theres no way to show a number like 67 no matter where you place it in the clock display..

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You can encode two full digits: XY = X:0Y. I.e. 67 = 6:07.

Wayne

wwhitney said:

turbo2ltr said:

The problem is the hours only go up to 30 something, and the minutes only go up to 59. So theres no way to show a number like 67 no matter where you place it in the clock display..

Click to expand...

You can encode two full digits: XY = X:0Y. I.e. 67 = 6:07.

Wayne

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Good suggestion.

Gary's idea of displaying kwh would also work ... but would involve some conversions.

garygid said:

That is why I suggested showing SOC scaled as "kWh remaining", 0 to 24, instead percent (0 to 100).

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I don't know. Might as well just look at the SOC bars at that point as you are losing 75% of your resolution.

turbo2ltr said:

I don't know. Might as well just look at the SOC bars at that point as you are losing 75% of your resolution.

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What is the underlying resolution of the CAN messages? Kwh to one decimal place is actually a finer resolution than SOC as an integral percentage. Either one would be plenty, I would think.

Cheers, Wayne

less than 1.

I was going to say that you can't just convert SOC to capacity without taking into account the long term loss of capacity and without knowing what the BMS is/isn't correcting on it's own. But technically there is no guarantee I have found SOC and not capacity. It could be capacity remaining, meaning that it's not corrected for long term loss of capacity and full scale "100%" will dwindle over time. I can't think of any way to know the difference without simply seeing what happens over time. I suppose if it were capacity, battery temperature would effect the 100% value, but it's all unknown at this point. (Damn I need that giant refrigerator again)

What we do know is that this number I found is the basis of the range calculation. So one would think that as capacity drops, so does the range, therefore so must this number, which would seem to indicate that this is not SOC but capacity. But, that all depends on which module is compensating for loss of capacity. More tests!

I'm enjoying watching progress being made, even when it isn't. Keep up the good work.

I'm sorry to hear that your "re-purpose an existing display" scheme isn't working for you so far. Are the clock and temperature gauges pretty much the only ones that had potential?

Regarding the "install an external display" plan, I still would like to have the option of using the display that I already haul around every day: My smartphone. "Need to see your SOC? There's an app for that."

Also, if one was able to get certain data into a smartphone or tablet, wouldn't it then be possible to pipe that data onto the Leaf's nav display, perhaps as an RSS feed or something? It seems silly to have to send that info through the internet and two separate cellular connections, but it might work in a pinch. Maybe.

But a "dumb" display wouldn't be bad either, and would have a lot less dependency on user-supplied gear and software. Would you be able to use one of the many existing "OBD-II gauge" products, and feed it some suitably massaged data?

Sorry, I mean XY.Z (00.0 to 24.0) displayed in the peculiar XY:0Z format for kWh, or perhaps use 0.0 to 25.0 for 1/4 of the "percent SOC" value, just so we can watch a "high-precision" value and get some experience with it.

When you cycle that center display to other data, miles per kWh is shown, right? That would display a Y.Z or XY.Z format, right?

The average m/kw on the dash is calculated by the dash as far as I know so it's not overrideable.. I know my number never matches the average on the Nav system.

I found that the buttons for the NAV have their own CAN bus. I haven't tried yet (well haven't tried hard), but in theory I should be able to emulate button pressing. Unfortunately, I cannot emulate the "I agree" button press on the screen which is what we really want. But it would be nice to have something that selects the power screen automatically, which I'm quite sure is doable. The problem is doing so will is essentially the same thing as pressing decline. So it would only work if you don't care about carwings data getting uploaded.

On the nav screen - what I really want is a "recall" button. I toggle between the music screen and the energy utilization screen.

While Leaf displays the track it is playing at the bottom of the map, it doesn't do that for the EV screens.

evnow said:

On the nav screen - what I really want is a "recall" button. I toggle between the music screen and the energy utilization screen.

While Leaf displays the track it is playing at the bottom of the map, it doesn't do that for the EV screens.

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I misspoke. There's no way to get to the energy screen using buttons alone....typing before thinking is never good.

turbo2ltr said:

What we do know is that this number I found is the basis of the range calculation. So one would think that as capacity drops, so does the range, therefore so must this number, which would seem to indicate that this is not SOC but capacity. But, that all depends on which module is compensating for loss of capacity. More tests!

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Any news ?

BTW, instead of time to charge you could use one of the other stats Leaf can show in the same place - like Avg speed.

Nothing yet. Been super busy. I did get a display in that I plan to use...details are still sketchy.

Everything on the dash LCD (aside from charge time) as far as I can tell is calculated in the dash itself so there is no direct CAN message to override. I did do some testing and it does not appear overriding would have worked anyway. I tried to override the range with SOC and it would continously flash back and forth. I originally had reason to believe there was some delay in displaying the message that would have let it work, but that does not appear to be the case.

Looking forward to your CAN bus findings once you have the update on your Leaf done. As far as the update goes

Wait Master, it might be dangerous... you go first.

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:lol:

I dont plan to get it done. Currently testing with someone elses car..