Make my own carwings remote status upgrade

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chris7

Member
Joined
Apr 15, 2015
Messages
11
I am leasing the base model 2015 Leaf without Carwings. I really want to be able to get notifications of when the car is charging, when it's unplugged or finished. My options as I see them are:

1. Try to get Carwings added on. I don't think that's possible though, as I've got the old nav system. Also it would create problems with my lease.

2. Connect something like a Raspberry Pi to the ODB2 port, and detect charging status through there. I think though that the ODB2 port is off when the car is off, and I'm not sure if ODB2 has fast notifications of being plugged or unplugged.

3. Create my own cover for the LEDs on the dash. Have light sensors in the cover which feed to a Raspberry Pi or similar. It would detect the charge status through the flashing of the LEDs on the dash, and report through wifi back to me the current state.

Note: I know that the Chargepoint ports can notify me if I used my card to start the charge, but when I park at work we share chargers, and I can be plugged and unplugged using someone else's chargepoint card so I want notifications straight from my car.
 
chris7 said:
3. Create my own cover for the LEDs on the dash. Have light sensors in the cover which feed to a Raspberry Pi or similar. It would detect the charge status through the flashing of the LEDs on the dash, and report through wifi back to me the current state.
Simpler version of this option:
  • Get an old Android phone.
  • Install something like IP Webcam on it.
  • Mount the phone in the car with the camera pointing at the charging lights.
 
Interesting idea with the phone but I see battery life and lack of notifications as issues.
 
chris7 said:
Interesting idea with the phone but I see battery life and lack of notifications as issues.
To solve battery life, wire a charger for it to one of the Leaf's always-live lines.

For notifications, you can write software to monitor the video stream & notice when the light blinking changes.
 
One thing I'm worried about is the fact the lights are hard to see at some times on the dashboard in direct sunlight, so image processing might have a hard time sometimes unless I stick a dark cover over them, but it might be do-able.... I thought a cover with one sensor per LED might work.
 
Silly me, I was just looking for the wiring diagrams for the car to see if there was some device that I could talk to with a simple protocol to get the info I need, and I come across this one:

http://www.nissanpartsdeal.com/parts-list/2015-nissan-leaf/instrument-meter-gauge.html" onclick="window.open(this.href);return false;

which shows the LEDs on the dash can be removed as a piece. So I just went out in the dark and took a look, and indeed it easily is removed with a small amount of force on a little screwdriver. Underneath is a PCB with a connector on it. The connector is electrically connected to the PCB through some pretty long bare metal that does a 90 degree turn. There are 4 wires on the connector.

So, looks like my best bet is to track down a matching male and female socket so I can get in between the existing connector, and start spying on stuff, or just attach something to the bare metal. When it's daylight and I have some time I'll spy on the signals and try to figure out what connector it is and if I can get some.

Hopefully the wires are simple ground, with a signal for each LED. That would be easy to spy on. Although it's possible it's some communication bus... None of the wires are black, which I'd expect if there was a ground.
 
So I took a look and it's just a ground, and one positive for each LED, driven directly through a 4700F resistor, to the LED with a parallel capacitor. I haven't measured the voltage, but presumably it's 5 or 12. So, I'm in business. Now I just need to figure out how to power it, which depends on the processor. It really only needs to be on while the LEDs are on, so I could set them up to power on the processor, and then let the processor power itself down when it's sent its final notification.

What's the lowest power device that's small, can take some unclean 12 or 5v signals as inputs, doesn't mind being too hot, and has integrated or easily added wifi? Oh, and a sub-second boot. I haven't used an arduino, or a raspberry PI (apart from installing xbmc). I'd prefer as little soldering or making my own PCBs as possible. I can do all of that, and can program, but want to spend as little time on this project as possible..
 
I've decided to go with a Spark Photon (also known as Particle Photon).
https://www.particle.io/" onclick="window.open(this.href);return false;

$19, comes with wifi, easily integrated with IfTTT for notifications etc, simple development environment. Can take 5V inputs, if indeed that's what my LEDs are (and if not, I can convert them.) Looks like it's pretty low power, so I can get by with a battery. I'm not sure if I'll be able to charge it from the car or maybe solar. Or can leech power from the LED signals....
 
Never mind garsh - I managed to attack the car with a multimeter, and found that:

1. The LED signals are 12V, so I'm going to have to do some conditioning before feeding into the microcontroller.
2. The middle column of fuses in the fuse box are all live when the car is off.

So I think I have a plan of attack. Just need to wire in a high efficiency USB charger to an always-on fuse to power the circuit at 5V (probably gut one that I already have), and to convert the LED signals to 3V with some tiny circuit I'm sure involves a diode. Hopefully this all fits in a little indentation in the dash under the LED cavity that I found.

I still need to find the right connectors though to intercept the LED signals so I don't have to solder on there or clamp onto the bare copper....
 
According to page EVC-334 of my 2012 manual, pin #4 of the connector is +12 volts, and the other 3 pins get switched to ground by the VCM to turn on the LEDs. You could probably directly use the ground signals to control your Spark Photon, as long as you use some diodes to isolate them from the 12 volts coming through the LED's, or maybe some zeners to limit the voltage that the Spark would see.
 
Doh - thank you.
I'm used to ignoring the sign on the display, and the way I hold the probes. Absolutely I could have been measuring a constant 12V with LEDs that ground it. Whoops.

That's great. It is probably a constant 12V that I can use to power the circuit so I don't need to run a wire from the fuse. Or even if it's only active while the LEDs are doing something that would probably still work (maybe even better). I should be able to find a ground somewhere close.

And yes, I can use a pull-up to 3V on each of the inputs (I think the microprocessor has those internally, but maybe not low enough impedance), and a diode that lets the LED signals pull that low.

Which manual are you looking at? Is it downloadable?
 
I downloaded most of the 2012 manual from Nissan years ago. The EVC section is the one I got the most info from for you:
http://www.electricvehiclewiki.com/Nissan_LEAF_Service_Manual" onclick="window.open(this.href);return false;
There used to be a link to the manual in another thread, but it is gone.
 
Can you fill me in with how you plan on using the WiFi functionality of the Photon board? What are you using on the other end to receive it? Or, are you hoping to use it to log on to a public WiFi network in the area, or a peer-to-peer network connection? Just curious. :D
 
chris7 said:
Never mind garsh - I managed to attack the car with a multimeter, and found that:

1. The LED signals are 12V, so I'm going to have to do some conditioning before feeding into the microcontroller.
2. The middle column of fuses in the fuse box are all live when the car is off.

So I think I have a plan of attack. Just need to wire in a high efficiency USB charger to an always-on fuse to power the circuit at 5V (probably gut one that I already have), and to convert the LED signals to 3V with some tiny circuit I'm sure involves a diode. Hopefully this all fits in a little indentation in the dash under the LED cavity that I found.

I still need to find the right connectors though to intercept the LED signals so I don't have to solder on there or clamp onto the bare copper....
With a small rechargeable battery on the first LED (the one most likely to be on during charging) and a simple circuit to limit the voltage to battery charge level, you might be able to power your circuit from that...
 
keydiver said:
I downloaded most of the 2012 manual from Nissan years ago. The EVC section is the one I got the most info from for you:
http://www.electricvehiclewiki.com/Nissan_LEAF_Service_Manual" onclick="window.open(this.href);return false;
There used to be a link to the manual in another thread, but it is gone.

Thanks. Not nice they charge for it though...

keydiver said:
Can you fill me in with how you plan on using the WiFi functionality of the Photon board? What are you using on the other end to receive it? Or, are you hoping to use it to log on to a public WiFi network in the area, or a peer-to-peer network connection? Just curious. :D

I charge at work, where there's open wifi available, and at home, where there's my wifi available. If it just works in those two places I'm a happy camper.

ishiyakazuo said:
With a small rechargeable battery on the first LED (the one most likely to be on during charging) and a simple circuit to limit the voltage to battery charge level, you might be able to power your circuit from that...

Yes, although I'm not sure how much power is available from that LED signal. Plus I think having a floating ground (when the LED is off) is suboptimal. Finding a piece of metal to act as ground somewhere around (the body of the car can still be trusted to be ground on the leaf, right?) shouldn't be that hard, compared to when I thought I needed to find a 12V.

I'll test max current on the 12V and LED signals to see what I'm playing with.
 
Hey, keydiver et al.
Any updates? I bought a 2015 S and this feature is the one I miss from not getting the fancy nav unit.
I've been thinking of hacking a GPS tracker I have, which has a cellular radio for connection...
 
Nah, I haven't had enough time to try it.

I have a 2017 base model leaf now, so it would still be a good project, but I don't think I'll get to it this year.
 
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