There is a lot of hope that car-computer integration can improve the experience of driving an electric vehicle. The GM Volt, for example, runs software containing 10 million lines of code. But where it really seems like computing could help is in improving the operation and maintenance of these vehicles. Understanding how batteries are performing under real-world conditions transforms every driver into a part of the R&D operation.
One driver of the fanciest electric car, the Tesla, wanted to know just what data his car was collecting on him. So he hired a software geek to reverse engineer the car's data logging apparatus. Among other bits of information, it turns out Tesla's logging data every second while you drive.
After some digging I found information on the Tesla Motors Club forum about log files that can be collected via a cabin USB port. To get the logs use a USB stick and add a folder named "VehicleLogs" to the root, plug it in, turn the key on and off and watch the screen tell you it is downloading the logs.
I have no idea why, but it takes about 15 min to download a 12M TAR file. As one can expect the data logs are not in clear text, but rather a proprietary binary format. After some more digging I found a Tesla Motor Club post on the format of the binary data logs done by someone with way more time than myself. Head nod to scott451 and tomsax.
The binary file contains two sections, the first is a long term data logging section with 1 entry per day since the vehicle was made along with firmware update information and other vehicle data. The second section is an 8M wrapped block for data on driving and charging of the vehicle. Data while driving is saved once per second, minute and 10 minutes. Data from charging is once per minute as well as other unknown entries.
Read the full story at MyBitBox (via Slashdot).