Using clone ELM327 Bluetooth OBDII adapter with Leaf

Added in max and min cell pair voltages but instead of an average I have added the difference between best and worst CP in millivolts in parentheses after min voltage. The smaller the number the better balanced your pack is.

(The Leaf is out so this picture is taken with test data.)


Leaf is back so here it is again with real data. Put code in to auto adjust the y-axis grid interval.


Just enough room for average CP voltage. Note CP difference dropped to 12 millivolts from 16 after sitting for 30 minutes.

The AT&T Fusion 2 Android smartphone is $80 at Fry's now.

Do I understand right that when one buys this phone, it does
not need any activation, payment plan, etc. to be able to use
it in the Bluetooth or the WiFi mode, just like a little tablet?

Does anybody know where it can be ordered for $40 or so?
Thanks

Now, we should add this screen to CANary.
If you do not mind, I will add a CP Bars screen to CANary
tomorrow morning, updating rev47-gg1 to rev47-gg2.
You are busy doing great things with the Android app.

If you post or PM a link to the app, I could try it out
with my Android Tablet.

Gary,
You don't need to activate it and everything works (Bluetooth, WiFi, GPS, Play Store). In an emergency 911 will also work. You can get an unlock code and use it on any network. Once unlocked you can buy any SIM card with minutes and use the Phone. Great for travel to other countries.

There are map apps that download map sections to the uSD card so you can use them with the GPS with no network connection when you travel.

Just wait a while and Fry's should have them on sale again.

Your Histogram code is on the list to get ported as well as regen braking ;-)

When will you mod the device to try and read from the EV-Bus? I'd love a simpler way to get the SoC w/o having to purchase a dedicated (and pricey) device.

Looks like GregH has identified a high resolution SOC value which I can read out from the CAR-CAN. So no need to rewire the ELM to get SOC.

I should have %SOC added by this afternoon to the display. On my car after a full charge the value I read showed 94.6622% SOC using the ELM327 with a gid count of 263 from my WattsLeft before I swapped in the mini ELM327. Same value on GregH's car read 49.4884% with 142 gids read from his gid meter.

Awesome! Does it matter which Bluetooth reader I buy?

Exciting times! I just ordered myself an mini module. This is going to be great fun. I'm amazed that all the info we really wanted was available on the CAR-CAN bus all along. I look forward to the point when you think you can alpha the code/app out to folks.

Alright, I just ordered the mini from Amazon using Prime. Once the app is ready, it should work on a Kindle Fire HD too right? That would save me from having to buy an Android phone.

For small size I would get the mini which is what I currently use.

Just added the code to request and save the group 1 battery message response which has the HiRes SOC.



I will probably put back the top status line as you need it to access the pairing request when you first plug in the BT OBDII adapter.

Now that I have the SOC I will add code to read every second or so. With so much resolution the low digits move fast when charging or driving. Did not seem to change when car was off and headlights are on. But once I turned on the car it updated to a lower value.

This is awesome! I can't wait to try it out!

Why every second though? Wouldn't every 30s be sufficient? Or at least, make it configurable?

Yes there will be a setup screen where you can change various parameters like sample times.

I have just added one of the most important pieces of information you will need, your battery pack health.

After SOC there is now a CAP value which should be the current capacity of you battery pack. This is how much energy you can store in the battery not how much is currently there. I my case with about 24,000 miles my max gids at 100% charge is 263 (263/281 = 93.59%).

This could be important information if you are going to buy a used Leaf. So even if SOC is 10% the CAP still tells you how high you could charge it to.

Will the source code for your app be available? I'm primarily interested in the Bluetooth stuff and the commands.

There is still alot of work to do on the code. So for now, I will probably just make the apk file available for testing.

Are you familiar with Basic4android? I am learning as I go.

Things to do:
- Auto polling for data
- Gary's Histogram code for CP voltages
- Screen to show braking split between regen and physical brakes.
- Saving data to uSD card
- Parameter setting menu
- Trip/Charge duration timer
- Power/Regen meter (if battery current/voltage is readable from CAR-CAN)

What other things are people interested in seeing?

One thing to keep in mind is that the BT OBDII adapter is always powered on when plugged in. It is warm to the touch when I pull it out. So it draws a lot of current. I will have to measure the current some time. My WattsLeft product draws less than 2ma in sleep mode so there is no danger of draining the 12 volt battery if left in all the time. That may not be the case for the BT OBDII adapter.

The internet has a few examples of Windows Phone 8 working with SPP based Bluetooth devices, so I wanted to see how you send commands, and which commands so I can try it on WP8.

The commands I issue to get the pack data are listed on the first page. They look like modem commands and start with AT. The last one "21 02 is the request to the car. Look for GregH's post on how to decode it.

If you go to the ELM website you can download their manual (http://www.elmelectronics.com" onclick="window.open(this.href);return false; look for ELM327 OBD to RS232 Interpreter).

I didn't see any posts on where SoC and Capacity for the LEAF are, would you mind detailing?

I guess GregH has not had time to update his post yet. He just found those two this morning.

Group 1 (21 01) SOC = 5th line last three bytes, CAP = 6th (last) line second, third and fourth bytes.

Thanks!

Turbo3 said:

I guess GregH has not had time to update his post yet. He just found those two this morning.

Group 1 (21 01) SOC = 5th line last three bytes, CAP = 6th (last) line second, third and fourth bytes.

Click to expand...

I've added the hi-res SOC info to the first post in my thread, also copied the temperature data there as well. I'd been hesitant to post the capacity details until we can get a few more cars to confirm, but it looks like the Ah capacity as XX.XXXX Ah (66Ah in a new battery) and its in the 3rd-5th bytes on the last line of group 1. My new pack reports 0A12E6... 66.0198Ah.

Is your CAP% a percent of 66 amp-hours capacity, which is assuming
that a new battery pack holds 66 amp-hours when "fully" charged
to 281 GIDs?

Is this SOC just a high-resolution version of the SOC read from
the EV bus messages?

Note that the %SOC is of little use during driving, and the extra
precision is useless. When the capacity is down to 50%, the SOC
will still read around 95% after a full charge, but the %GIDs (percentage
of 281) will read about 50%, indicating an estimate of the usable
fuel on board.

Also, since the battery pack declines in voltage as it is discharged,
one amp-hour from a nearly fully charged pack provides more energy
than one amp-hour provides when the pack is mostly discharged, a
ratio of about 4:3 between the two.