LeafCAN v2 Firmware in Alpha Test

I have been working on v2 of the LeafCAN firmware, which adds a whole slew of new screens, selectable via a rotary encoder.  The rotary encoder is connected to the AD0/1/2 pins on the expansion header of the LeafCAN V2 hardware.  The code is currently in alpha testing, and is available in the development branch of the LeafCAN github repository.  Be aware that the development branch is for my bleeding edge code, and at any time, the code there may be broken, as I continually checkpoint my code.  I will move it to the master branch when it’s ready to be released.

While I was developing the LeafCAN v2 firmware, I received a pleasant surprise in the mail from Barbouri (GregC) of the MyNissanLeaf forum.  He designed a PCB with 16×2 OLED display + RGB Led Rotary Encoder support,

v2o

and sent me a completely assembled and tested rig.  I immediately added support for this new hardware variant into my working LeafCAN v2 firmware code.  The RGB knob is cool:

encoderled

but I am still pondering how best to use it. Currently, I have it blue when the car is idle, red when it’s consuming power, and green during regen.
Below is an overview of LeafCAN v2Alpha3. The various screens are selected by rotating the encoder knob. Some of the screens have different modes, selected via a press of the encoder knob. The first screen is the familiar info screen from LeafCAN v1.3:

mainscreen

The top line from left to right is: kWh remaining/gids/fixed fuel bars, and the bottom line is: pack voltage/SOC%/instantaneous kW. The next screen is an idea lifted from Turbo3’s WattsLeft, the DTE (distance to event) screen:

dtel

The top line shows various miles/kWh values, 2.0/3.0/4.0/5.0/6.0, and bottom line shows the distance in miles to the event, in this case, Low Battery.  Pressing the encoder button switches it to miles until Very Low Battery:

dtev

and pressing the button a third time shows miles until Turtle:

dtet

Thanks to a breakthrough in active can sampling, spearheaded by GregH and TickTock, I was able to implement the following new screens. The first one has on the top line, High Precision State of Charge (SOC)%.  The bottom line shows State of Charge (Ah), and possibly a Battery Health %.

soccap

The next screen shows the 4 battery pack temperature sensors:

batttemp

The units are selectable between Celcius and Fahrenheit with a press of the button. Finally, the last screen shows the minimum and maximum cell-pair voltages in mV, as well as their difference:

cellvolt

When an OLED is installed, the display now blanks after 5 sec of inactivity on the CAN bus. Pressing and holding the knob for a second wakes the display up for 5 sec.  When an LCD is installed, the press/hold turns on the backlight for 5 sec, instead.

I will be working towards finishing LeafCAN v2.0 in the coming weeks, and will announce its release here.

Barbouri and I are also collaborating on a dual-CAN bus version of the LeafCAN hardware, which will be able to monitor the Car-CAN as well as the EV-CAN on the Nissan Leaf. This will open up access to various information which is accessible only via the Car-CAN, such as friction brake actuation, steering angle, etc.

I would also like to point out that GregH has yet another cool Leaf CAN bus dash display in the works (only $80) that is worth checking out. Also, TickTock and garygid are working on the very fancy dual-touchscreen open-source CANary Project. Turbo3 has also figured out how to extract data from the Leaf Car-CAN using a cheap ELM-327 clone dongle and an Android phone. There is currently a flurry of CAN bus hacking on the Leaf.

There are 5 Comments to "LeafCAN v2 Firmware in Alpha Test"

  • Norman says:

    Do you know how to read VIN, speed, and charger volts and amps for the Leaf?
    I have some other info from GaryG. Working on iPhone and Bluetooth project to look at CAR and EV bus to do carbon comps to other EVs and std vehicles.
    Thanks
    Norm

    • lincomatic says:

      Unfortunately, not. Almost all of the messages I’m aware of are in the LeafCAN code. CANary attempts to make calc speed and distance from the “motor RPM” number, but I don’t know how accurate it is.

  • Mike says:

    Have you made any revisions to the project to replace the “possibly a battery health%” number with the actual SOH%, as discovered by TickTock here?

    • lincomatic says:

      Sorry, I’ve been out of the loop for a while. What is SOH%? I tried searching the forum and couldn’t figure it out.

      • Mike says:

        Did you try my link to TickTock’s post in the MNL forum? SOH is located at 5b3:D2 and appears to be an accurate measure of battery capacity (as a percentage of new.) Also, multiplying a constant for new battery capacity by SOH and SOC would give a better, higher resolution measure of the kWh in the pack than using GIDs.

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