What made this project particularly interesting is that technology-wise, it’s a blank slate. Usually you’re limited to working within some established boundaries, like an existing PCM, dash layouts, and so on, but with this car I didn’t have any of those issues to worry about. There were a few things that I wanted to do right out of the gate:
- Eliminate all mirrors and install side and rear cameras
- Have a central touch screen interface that controls the top, lights, wipers, climate system, audio, and navigation
Finding the cameras and screens was easy, and the prices now are ridiculously low compared to what they were just a few years ago. I ended up getting everything I needed from Amazon.
I put a lot of thought into how I wanted to do the central computer. There are tons of options that allow for the use of tablets, but I didn’t want the tablet to actually be the brains of the operation, just an interface to it. The primary goal was for the computer to be “headless” (in geekspeak, that means it doesn’t have a direct interface like a screen or a keyboard, it just works in the background doing it’s thing), and then a tablet or phone could interface with it. Ideally what I wanted to do was have a mini server that controlled everything, and I could connect to it through any web browser.
Enter the Raspberry Pi and SainSmart 8 Channel Relay. Basically here’s what’s going on; the Raspberry Pi is configured as both a wifi hotspot and a web server, which connects to the 8 channel relay board. Through a series of server-side commands I can control whether power flows through the relays or not, which let me design a web-based interface to turn the relays on and off. Amazon links below:
See where this is going? I can now wire the lights, top controls, wipers, and basically anything else I want through these relays and then control whether they’re ON or OFF through my browser! This is really powerful, because it means that:
- Any device – a tablet, my phone, laptop, whatever – can connect to the car’s hotspot and control all of the vehicle functions through a browser.
The possibilities are truly endless. I’m even considering making an app for my Samsung SmartWatch so I can raise and lower the top from the watch as well. Since the watch interacts with apps on my phone, really I would just need to create an app that executed a script on the server. Of course, this complicates the setup a little bit but it’s actually still possible. Instead of the Pi just being a WiFi hotspot, I could actually configure it as a router and get Internet service via a MyFi device from any of the major carriers. That would give the car a permanent internet connection, so I could connect to it from anywhere in the world. Obviously there are some security concerns to work out with that, but the point is it’s possible!
One thing at a time though… anyway, since I do want to have a permanent-mounted tablet (even though it’s just running a web browser), here’s the interface I designed for that. And I’m proud to say that over Thanksgiving weekend 2014 I actually made it functional. Photo attached of the relay board and Pi all wired up and running.