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LakeLeaf
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Re: My findings on the CAN bus

Sun Feb 20, 2011 5:38 pm

turbo2ltr wrote:I've never used a SG but i took a quick look (so I could be mistaken) through their manual. It seems the custom messages you can program are OBDII messages (686A...) Yes you can do OBDII over CAN, but everything I've done so far is at the CAN message level. I've been dealing with raw can messages already being broadcast on the bus. OBDII is a higher level protocol that requires a request in order to get a response.
That's my understanding too - you (or the SG) puts a request on the bus and listens for, and decodes and scales the reply. The user programmable portions are called the X Gauges.

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evnow
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Re: My findings on the CAN bus

Sun Feb 20, 2011 6:31 pm

turbo2ltr wrote:According to my math, Low battery warning happens at 18%. Very low battery happens at 9%. Turtle mode happens at 2%. Some of you guys have done tests, how does this compare with what you came up with?
According to Nissan - low battery accors when 4 kwh of capacity remains. If we assume 24kwh, that is 16.7%. Quite close.

I didn't know there is a "very low" battery level as well. I thought after low battery, you went into turtle ...
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Carcus
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Re: My findings on the CAN bus

Sun Feb 20, 2011 6:55 pm

Will CAN bus info finally and definitively tell what the total capacity of the pack is ??

/inquiring minds want to know

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LEAFer
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Re: My findings on the CAN bus

Sun Feb 20, 2011 7:21 pm

[quote="evnowI didn't know there is a "very low" battery level as well. I thought after low battery, you went into turtle ...[/quote]
Yup ... I hit "very low" at least twice last Sunday on my "limping" return to home base ... I did see "---" on the range, but have still not hit "Turtle" ... I guess I need to become even more "adventurous" :lol:
2011 Silver SL+QC [Mfg: 11/2010] 36mo/15k LEASE
06Jun2013 Status [28.5 months][34,173 miles][11 bars]
Lost CapacityBar 6/6/13 @34,173 miles while in LEAF Battery Monitor: 83.41%, 71.4F (avg); cool overnight;

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Jimmydreams
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Re: My findings on the CAN bus

Sun Feb 20, 2011 7:29 pm

LakeLeaf wrote:
turbo2ltr wrote:I've never used a SG but i took a quick look (so I could be mistaken) through their manual. It seems the custom messages you can program are OBDII messages (686A...) Yes you can do OBDII over CAN, but everything I've done so far is at the CAN message level. I've been dealing with raw can messages already being broadcast on the bus. OBDII is a higher level protocol that requires a request in order to get a response.
That's my understanding too - you (or the SG) puts a request on the bus and listens for, and decodes and scales the reply. The user programmable portions are called the X Gauges.
So if Tronz figures out where the raw CAN messages are being broadcast, can't we just program an Xguage 'request' for the information and then decode the result?? (Obviously, I'm not that technically minded, but my SG does do X Guages)
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turbo2ltr
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Re: My findings on the CAN bus

Sun Feb 20, 2011 7:55 pm

I didn't know there is a "very low" battery level as well. I thought after low battery, you went into turtle ...
Keep in mind that "tricking" the car like I was might change it's behavior, but there was a definitive repeatable pattern. There was a low battery warning which popped up on the dash and turned on the "gas pump with a plug" light.. Then there was the very low warning, which also prompted the NAV system to ask if you want to find nearby chargers and changed the warning on the dash LCD to indicate 'very' as well as changed the range to ---. Then there was turtle mode which illuminated the turtle light.
Will CAN bus info finally and definitively tell what the total capacity of the pack is ??
Anything is possibly but CAN messages usually do not contain "static" type data.
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AndyH
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Re: My findings on the CAN bus

Sun Feb 20, 2011 8:07 pm

Carcus wrote:Will CAN bus info finally and definitively tell what the total capacity of the pack is ??

/inquiring minds want to know
My guess is no, because all of the car's systems keep us in the 'consumer safe zone'. There might be capacity info in the battery controller we can requst/retrieve with a diagnostic too, but I can't see a reason why it would be broadcast on the buss.

Herm
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Re: My findings on the CAN bus

Sun Feb 20, 2011 8:08 pm

Carcus wrote:Will CAN bus info finally and definitively tell what the total capacity of the pack is ??

/inquiring minds want to know
If you kept track of pack or module voltage you may be able to figure it out if you make certain assumptions on cell chemistry.. should not be too hard to obtain, but please dont get electrocuted. We will know soon.

GroundLoop
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Re: My findings on the CAN bus

Sun Feb 20, 2011 10:37 pm

I know people keep holding out hope for the ScanGaugeII, and I have one myself, but it's really not a fit.
It just does ODB-II messages -- first over the ISO9141-2 low-speed bus, and then using OBD over CAN.
I don't think it can do generic CAN message snooping, but I could be wrong. I think only does OBD queries over CAN.
You can't tell it to watch for a specific message, interpret the data this way, and display it. At least, that wasn't in my manual. :)

One option for display would be to grab the "true" SOC and re-purpose some part of the LEAF dash to display it.. like the Range display. Just override the display messages coming from the ECU with SOC. I don't know if you would have to intercept (reroute, drop message, insert new one), but since you were able to already display your own values, I suspect you can do it through the port already.


If you can display text on the "time to charge" display, even better.

This is actually similar to what the Tesla did with the Lotus dash. It's all CAN messages, on a separate bus than the motor/brake controls. They just re-used the LCD display are for more Roadster-specific things, last I saw.

GroundLoop
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Re: My findings on the CAN bus

Sun Feb 20, 2011 10:38 pm

Another useful feature would be a Carwings "agree-er", if you can spoof button presses over CAN.
A ped-warning disable too. Something to hit the button for you on power-on.

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