Can I get this information from CAN bus?

I have an old Jeep Grand Cherokee where the most advanced electronics is the radio. I want to make a blind-spot warning using the VL53L0X Time of Flight Micro-LIDAR Distance Sensor

The sensor works through my rear windows, but it is alerting me anytime a car is next to me. I would like to only show the alert if one of the turn signals is activated. Can I determine if the turn signal is activated from the CANbus?

But it then has a CANbus? :face_with_raised_eyebrow:

I don't know. I thought CANbus came with ODB2?

You need to get google out and see how it works - if there is a module you maybe able to get data from it , but you need to know the message format -I would have thought unlikely.
It might be easier to take a signal from the indicator stalk , or most indicator connections may be on the back of the hazard light switch .

It would help if we knew the year. Before OBDII and concurrent with it for a while Chrysler also used a network called CCD (Chrysler Collision Detection). Not everything was on the CCD bus nor was all the CCD information placed on the CAN bus. There may also dealer specific information on the OBD II interface which you normally cannot access.

It is a 2003 Jeep Grand Cherokee. Ancient. I couldn't find anything that describes what is on the CANbus- I am wondering if I could just build something to snoop on the CANbus similar to MQTT Lens....

Go to an autoparts web
Searh for lamps.
Make model and year of vehicle
It should tell you replacement lamps for turn signals and brake lights.
If the lamps are Can bus. Bob's your uncle.
If easy to access then pull a bulb and check.

They are $1 incandescent lamps invented in the 19th Century. I've never heard of a CANbus lamp.

I am planning on using ESP Local to communicate from the LIDAR to my display. (Right now it's all on a breadboard). I could add a node to get the state of the turn signals, but I was hoping that there would be an easier way.

Put an Optocoupler across the direction indicator lamp and use it to signal that the indicator is on/off/on/off/on/off...(I gotta get the blood out of my caffeine system.)

Tom... :smiley: :+1: :coffee: :australia:

That's what I am thinking. I will code a missing-pulse detector so that the state isn't on-off-on-off.

My wife just wants me to get a newer Jeep. It would be easier, but what's the fun in that? Also, I am old and hate spending money. A new Jeep would cost more than my first house did.

Need to get out more.

The can bus lamp tells the vehicles MCU when it is out.

Just google can bus brake light and do a little light reading

Wow. Smart lights in the car. I never would have guessed.
No, my Jeep is so old fashioned that you know when a turn signal light is out when it mechanical blinker relay flashes quickly.

The flasher relay may be a pickup point to detect when a turn signal is activated.

Remember when if we wanted to know the weather outside, we would (gasp) look out the window?

Perhaps when windows in offices were popular? :grin:

Unfortunately your Car has not CAN bus but a PCI data bus ,something like a K-Line.
(CCD -> 1999 , PCI 1999 - 2005, CAN 2005 ->)
Hope this helps

1 Like

Thanks for the tip. I did find some data for the PCI Bus on my Jeep but the turn signals aren't on it.

I am just going to probe for a pickup point where I can put in opto-isolators. I'll start probing at the flasher relay.

You can use a voltage divider from the power to the turn signal light to one of the digital inputs on your arduino. If my memory is working your vehicle also has a single blinking light on the dash to let you know if the turn signal is flashing. Do not hold me to that it was a long time ago and I never owned or a Jeep.