OpenXC.

OpenXC is an API to your car – by installing a small hardware module to read and translate metrics from a car’s internal network, the data becomes accessible from most Android applications using the OpenXC library. You can start making vehicle-aware applications that have better interfaces based on context, can minimize distraction while driving, are integrated with other connected services, and can offer you more insight into your car’s operation.

Ford Motor Company and Bug Labs joined up to create a standard way of creating aftermarket software and hardware for vehicles. Every new car is full of computers and electronics, and there is growing interest in connecting the output from those systems to third-party applications and the web. Many companies are already offering tools to hook into the driver’s interface, but for the most part they have limited availability for hobbyists and developers. What if the system was designed from the ground up to be open source and to give insight into the vehicle itself? With proper hardware isolation to ensure you can’t “brick” your $20,000 investment in a car, OpenXC imagines when your car is as easy to program as your smartphone.

Today’s version of OpenXC runs on a combination of the Arduino and Android platforms. It uses tools you already know and opens up thousands of possibilities.