DIY EBL (emergency brake lights)

[stephen byatt]

Hi all! I've built an Arduino/CANBUS thing to control the lights on my kit car. Which means I can make them do whatever I want, including emergency brake lights where the brakes/hazards/fogs can be activated according to whatever criteria I fancy.

I've not had a car with EBL before, and was wondering if anybody has any thoughts on the criteria should be. I was thinking:

Activate the rear fog lights and hazards if speed > 50kph and there's >0.5G of braking force over 0.5 seconds. There's no ABS or ESP on my car to use as a source/trigger.

Fogs lights off as soon as braking force is < 0.5G, and hazards remain on for three seconds after < 0.5G. If the car stops during harsh braking then the hazards should remain on until manually cancelled.

I'm asking because I don't want to annoy people behind me if it triggers to easily!

[stephen byatt]

FlossyThePig said:

Slightly off topic but tell me more about your Arduino/CANBUS project or point me to a site with more details. Can I use it to extract information linking it to the OBD connector on my car?

Check this link: https://wiki.seeedstudio.com/CAN-BUS_Shield_V2.0/

This, along with an Arduino to plug it into, will allow you to get frames from the CANBUS and then do whatever you wish with them. I use it to get steering wheel button presses to operate the lights, plus gps and accelerometer data from the data logger. You could also pick up engine data, gear box, etc etc. You can also write to the CANBUS to send messages to other devices on the network.

You’ll need to be able to do some basic wiring, but also some programming the Arduino in C. If you want a tool to simply read the OBD while static in your garage, there are far simpler solutions!