Car stereo/touch screen.

[zSmite]

So I want to turn my pi into a car stereo with a 7 inch touch screen. As far as software goes, I can do anything and everything I need to do, but when it comes to the hardware portion I am in definite need of help... I'm pretty sure I can get it wired into the speakers and screen no problem, I just need help with powering the device via the car and no batteries needed, and I also would like to have it wired to the ignition switch so it shuts off with the car. I was a mechanic for a good while so I know my way around a car, its just electronics I'm not the greatest at. Any suggestions for a starting point?

[chilinski]

Most cars these days come with usb ports and aux power ports. The aux (cigarette lighter) will give you the 12 volts that the screen undoubtedly requires and the usb port would provide the 5 volts. I'm sure they also make 12 volt adapters that have both built in...a usb port and a 12-volt port.

[stephen910]

I would just look at the wiring diagram for the back of the factory car radio. It will have the +12v you need and a switched out put. Or you could just get a relay and connect it into the battery and switched from the back of the radio.

I am in the exact opposite situation you are in, I know all about the hardware part and could figure out how to hook it up, but I'm having trouble with the programming part of it all. I'm thinking of the exact same thing as you with the touch screen.

Hope you figured it all out okay.

[guitarist46559]

I too am interested in doing a car stereo with a Pi/touchscreen. I'm no programmer, but I am a sys admin, and know my way around the Linux OS pretty well.

In my case, I have plans to use my stereos existing wiring harness for power. Problem is, my stereo turns off as soon as the key is turned off, and I don't want to subject the pi to that multiple times per day; it needs a graceful shutdown. Does anyone have any wise ideas about this? I found another thread that dealt with gracefully shutting down a pi thermostat in the event of a power outage by using several neat little circuits running on either batteries or super caps that tells the pi to shutdown when it detects power loss, but they didn't recommend using their circuit in an automotive application.

Any ideas?

[stephen910]

I read somewhere that you could hook the pi to the constant +12 from the back of the stereo. Then use the switched power connected to one of the GPIO and have that signal tell the pi to shut itself down. This will tell the pi to shut down when ever the engine is off I think thats what I am going to do.

[demesauce]

I know this an old topic. But I use products from Mausberry Circuits, they are fantastic for powering Pi projects. Here is the Car Power switches they sell:

http://mausberrycircuits.com/collection ... y-switches

Great products, fantastic customer service