I have an after market media/LCD screen which hooks up to my dome light. I want to hook up my raspberry pi through HDMI. I'm going to 3D print a case to sit along side my LCD media player. My goal is to wire the pi to my dome light coupled with a battery system and a relay so the pi can shut down each time when the car is turned off. I found an interesting thread on this:
I'm just not sure how I would wire this up through the dome light. Or is there another relay I should use. Or should I just connect the on/off wire to GPIO 5 and reduce to 3.3v? Really just not totally confident in how the relay works. I don't think there is a constant power to the dome light. There is a ground and a hot. But I would have to double check.
Also could someone draw up a diagram of how a car relay would hook up to a pi GPIO. I think I get it but I'm better with diagrams. Once I get it up and running I'll post my results and setup.
What would be the recommendation for reducing the 12v to 5v?
I did find this: https://www.amazon.ca/dp/B00C63TLCC/ref ... yAbT1ZXXV1