LEAF CANbus decoding. (Open discussion)

Sweet! It's better that it's the Nav time anyway, that's GPS based right?

JeremyW said:

Sweet! It's better that it's the Nav time anyway, that's GPS based right?

Click to expand...

That is my guess since it doesn't give you a "set" option, but rather, just the option to offset the time. Subtle difference but implies it is getting an accurate time from somewhere instead of generating it. I have added this to CANary and it seems to be working quite well to keep the clock synchronized. Now I need to figure out how to program the eyebrow clock via canbus so I can keep that one synchronized, too.

Where did you find the battery series resistance, please?

garygid said:

Where did you find the battery series resistance, please?

Click to expand...

It is a computed value. Once a second, I algorithmically find the value of Resr that minimizes the variation in the formula Vbat+Resr*Ibat. Once I gather enough data to show a trend, I hope to look for a message that tracks it. However, my Leaf really doesn't seem to be changing much - hovers around 100mOhms.

garygid said:

TickTock said:

Take a look at https://docs.google.com/spreadsheet/ccc?key=0An7gtcYL2Oy0dGRaSWl6VTV2eXBQMy1ON2xZSzlMUXc#gid=5 (be sure to note the different tabs at the bottom). It contains everything I could find that has been unearthed on the various canbus messages. The content came from the contributions of Turbo2ltr, garygid, and many others. If you discover anything useful (or not ) please let us know!

Click to expand...

Accessing the spreadsheet link from my Android Tablet,
I get what appears to be an endless loop (not tested
to the end).

Click to expand...

(Moving from the other thread)

Sounds like a GoogleDrive bug. See if any of these links work (other google docs):
https://docs.google.com/spreadsheet/ccc?key=0An7gtcYL2Oy0dGRaSWl6VTV2eXBQMy1ON2xZSzlMUXc#gid=0
https://docs.google.com/spreadsheet...RkNkFnaEVOQTVENW5mOTZlb0E&usp=drive_web#gid=1
https://docs.google.com/spreadsheet...dvOWktWjNITzhwbERWYmYyQVE&usp=drive_web#gid=0

Thanks, the other links helped me figure out that Google was in
a login loop, perhaps because I was already auto-logged in.

The loop was repeating too fast to use their enter password
and login, but I was able to use the "log out and login as another
user" link, and re-login and then I could see the spreadsheet.

Thanks, a good resource.

QC-CAN Bus:

Eventually you can add a QC bus sheet, with the five MsgIDs that I observed
(as I recall from the posted QC log), being hex 100, 101, and 102, apparently
from the car, and hex 108 and 109, apparently a reply from the QC device.

Perhaps the Description column heading should be "Description ( unofficial )"
or something similar, to indicate the tentative, uncertain, and unofficial nature
of our interpretations of the data bytes? Simply a CYA precaution.

There is a "QCMessage data decoding" thread specifically for QC CAN details:
http://www.mynissanleaf.com/viewtopic.php?f=44&t=6255" onclick="window.open(this.href);return false;

There is another related "Open Chademo... " topic here:
http://www.mynissanleaf.com/viewtopic.php?f=26&t=7764" onclick="window.open(this.href);return false;

Thanks Gary,
I created the tab but so far there doesn't seem to be much information documented in the thread (at least that I could find in a 5 minute search).

TickTock said:

garygid said:

Where did you find the battery series resistance, please?

Click to expand...

It is a computed value. Once a second, I algorithmically find the value of Resr that minimizes the variation in the formula Vbat+Resr*Ibat. Once I gather enough data to show a trend, I hope to look for a message that tracks it. However, my Leaf really doesn't seem to be changing much - hovers around 100mOhms.

Click to expand...

Have you noted the increased impedance at cooler temps? The LeafDD also records series resistance calculated at high current points and logs the SOC and temperature at the time the test is done. When we had a few cool days recently and the battery temps dropped from 27-33 down to 18-20 I also saw the impedance rise from 88-90mOhm to 100. Not a surprise I guess, but this is the first time I'd seen it numerically.

GregH said:

TickTock said:

garygid said:

Where did you find the battery series resistance, please?

Click to expand...

It is a computed value. Once a second, I algorithmically find the value of Resr that minimizes the variation in the formula Vbat+Resr*Ibat. Once I gather enough data to show a trend, I hope to look for a message that tracks it. However, my Leaf really doesn't seem to be changing much - hovers around 100mOhms.

Click to expand...

Have you noted the increased impedance at cooler temps? The LeafDD also records series resistance calculated at high current points and logs the SOC and temperature at the time the test is done. When we had a few cool days recently and the battery temps dropped from 27-33 down to 18-20 I also saw the impedance rise from 88-90mOhm to 100. Not a surprise I guess, but this is the first time I'd seen it numerically.

Click to expand...

Yeah, that does appear to be the case. I was reading between 89-99mOhm in the summer and now am seeing 102-111. However, I had a formatting bug in my tripLog so I only have a few datapoints (that I manually captured). I was rounding to the nearest tenth so all my tripLog entries read 0.1 :-/

TickTock said:

I was reading between 89-99mOhm in the summer and now am seeing 102-111. However, I had a formatting bug in my tripLog so I only have a few datapoints (that I manually captured). I was rounding to the nearest tenth so all my tripLog entries read 0.1 :-/

Click to expand...

That's what I've been seeing too.

A few more tidbits learned this week. We know that 1cb:d2,d3 is Target Braking and 1cb:d0,d1 is Regen Braking. The latter, however, is the target regen braking - that is, it is what regen would be applied if it wasn't limited by other factors (such as being in neutral, at 100% charge,no regen bubbles,etc). It appears that 1d5:d0,d1 is actual regen braking. When I change my braking monitor to use this value instead, the braking monitor correctly reflects the true regen response to applied pedal. Furthermore, this value very closely track motor amps * 1.3 (when the motor is generating power) - which takes me to the second tidbit. The target and actual regen signals do not include regen during coasting(foot off both pedals, but not in neutral). If you let off the accel, we all know regen is engaged. This regen is not reflected in these messages. However, if I instead use motor_amps(1d4:d2,d3)*1.4, that signal almost perfectly tracks applied regen when the brake pedal is used but also responds to regen during coasting. I have updated CANary to use this instead so the brake monitor reflects the true braking force from regen. Need to test a little more but will publish soon.

Good sloothing, TT.

I've ordered myself an isolated PCAN tool (CAN-USB) and plan on helping with more of the decoding on the car CAN bus. I'm really interested in the DC/DC converter operation and climate control. It would be nice for lower power charging with just the Brusa to shut down the pumps, on board charger and DC/DC since the Brusa does have a small (1 Amp) DC/DC available.

I'm also going to help where I can with the Open Vehicle Monitoring System support for the Leaf. I want to be able to see the actual charge rate while charging since the estimated time remaining with the Brusa running is always wrong. I also would like better remote climate control. I wouldn't pay for carwings and I'd like to help my fellow leafers do the same.

Some additional tidbits:
On the EVcan, message ID 0x54f has useful climate control information. I haven't figure out what exactly they represent, but D2 (third data byte) is zero when the AC is off and climbs to around 20 when AC is running. Might be related to the power, or maybe compressor speed, not sure but is only active when the AC is active. Similarly D5, bits 5:0 are zero when the heater is off but climbs to around 15 when heater is turned on. Again not sure what it is tracking but was useful for implementing the heater monitor feature on CANary.
More details on the unofficial Leaf canbus doc.

Good work, my friend.
Do you have the MsgIDs that GregH uses to determine the
J1772 Pilot signal percentage or Max-Amps value?

It would be nice to see what current capacity each EVSE has
to offer.

Cheers, Gary

I have finally added the SOH value to Leaf Spy Pro (0x5B3 D2). I have also kept the old "Health" value but renamed to "Hx". The percent capacity based on AHr is now gone as it was too confusing with all the different initial values for AHrs with different Leaf model years/firmware updates.

Here is a screenshot. Please comment if this looks right as it is not released yet so can still be changed.

(updated 11/14/2013)

Thanks Jim - very cool. Looks right to me.

The 3rd line, after "mi", could be ", 30 QCs, 2345 L1/L2s"
to give you a bit more space for larger numbers in the future.

Are the last 3 characters of the VIN a bit strange?

But, this should be in the Spy thread, right?
Excellent work.

It looks fine. It will be interesting to see how it changes in the heat of summer, as my AmpHrs have been constant recently.