Thread: Abruzzo2's Modular (non car-specific) Carputer

I am currently leasing a 2007 Mazda3. I still have 15months of lease term left, and I haven't decided if I am going to buy it when I am done or get something else. This is why I am planning on designing a modular form, so that if I do keep it, it will be a matter of plug and playing. Or potentially a little modification to place it in a different car.

The 3 has a 3.5mm input for an auxiliary sound device. This makes it quite easy to interface the laptop (which has a 3.5mm headphone jack) through using a simple Male/Male headphone cable. This was I do not need to set up the computer as the entire sound system controller, I can use a switch to turn it on when I am tired of listening to the Radio (Diehard NPR listener).

I want to use a laptop because of the built in power system that already exists. Currently the laptop has the ACDC converter that switches outlet based 120v/60hz to 18V 4.9A DC. Ideally, I could create a circuit that uses the Cig Lighter power to convert to the input requirement for the power jack on the computer. This circumvents most of the power supply issues involving rail wattage and distribution blocks.

This eliminates the need to tap directly onto the motherboard. It also gives me a pre-drilled hole to mount the housing for the power switch for the computer, don't worry, I do not plan on retaining the use of the cig lighter. Though I might put a relay or a switch in to diver the power to a cig lighter that I can hide in the glove box or something.

I have several old laptop screens that I have been playing with. But they are so old virtually no one has controllers for them. I have found a few "cover-all" controllers, but it really does nothing to reduce the price to make it worthwhile. I honestly think it would be just as easy to buy a small LCD monitor for home use, take it apart, and then use the VGA input to connect to the VGA output on the back of the laptop. More likely I will bite the bullet and just buy a small touchscreen and save myself a lot of integration hassle.

Considering the not touchscreen approach, I have a few ideas about making a custom shifter knob. Mini optical mice have very small electronic boards inside of them, I could use one of these to point at a trackball mounted on the top of the shifter to make it convenient to mouse around without moving my hand form the shifter.

I plan on using the Ultimarc Ipac interface for controlling volume and track changing, though I have been more concerned about power stuff first. I have not really done much about the human interface part.

I have some pictures taken to post, but they are still on my camera, and it take soooooo much effort to attach it to that USB cable...