Comment on Is there such a thing as an automotive relay with no resistor?
ThePantser@lemmy.world 2 months ago
You may be able to use a optocoupler to sense the horn then use that to trigger the relay. What are you trying to accomplish? Are you making like sensor to know when your car alarm has triggered?
cvieira@lemmy.ml 2 months ago
Right now I’m trying to hook up a custom dashcam that can show an overlay when the horn is pressed. It works via GPIO, and essentially just checks to see if a specific pin is connected to the ground pin. I figured putting a relay between those two pins with a small resistor for safety would be the least invasive way to do that.
ThePantser@lemmy.world 2 months ago
Why not just add a new switch or button to the car? Like a button for your left foot to hit like old headlight high beams were.
cvieira@lemmy.ml 2 months ago
The idea is that the dashcam can show when the driver presses the horn in a car accident without the driver needing to do anything different. Anyone can drive the car without any specific knowledge, and the camera will just work in the background.
If you’ve even seen police dashcam video with the text overlays at the bottom reading “[HORN] [SIREN] [LIGHTS] [BRAKE]”, this is essentially what that is.