At a recent hack-a-thon event, [Al Linke] tapped into a vehicle’s OBD port with an OpenXC vehicle interface and hacked an LED screen in the rear window to display data based on events. If you haven’t heard of OpenXC, you can expect to read more about it here at Hackaday in the near future. For now, all you need to know is that OpenXC is Ford’s open source API for real-time data from your vehicle: specifically 2010 and newer model Ford vehicles (for now).
[Al] connected the OpenXC interface to his Android phone over Bluetooth, transmitting data from the OBD port to the phone in real time. From here, the Android can do some really cool stuff. It can use text to speech to announce how much your lead foot cost you, add sound effects for different car events, and even interact with additional devices. Although he managed all of those features, [Al's] primary goal was to add an LED screen that displayed messages on the vehicle’s back window.
When the phone detected a braking event from the car, it directed the LEDs to light up with a “braking” image, adding some flavor to the process of stopping. He could also change the image to a “Thank You” sign with a waving hand, or—for less courteous drivers—an “F U” image with a slightly different hand gesture. You’ll want to check your local and/or national laws before attempting to strap any additional lighting to your vehicle, but you can watch [Al's] car light up in the video below. For a more detailed look under the hood, he’s also provided an Instructables page. If OpenXC catches on, the number of vehicle hacks such as the Remote Controlled Car may skyrocket.