Parking can be a challenge in big cities like San Francisco. Spots are scarce, regulations are confusing, and the cost is often too darn high. At the TechCrunch Disrupt hackathon recently, John Naulty reached for a Raspberry Pi to help solve some of his parking problems.

John explained that the parking spots near his home only allow two hours of parking. But he had figured out that you only get caught exceeding that if the parking enforcement officers see your car in the same spot for more than two hours. If he could somehow know when a Meter Maid’s Interceptor drives by, he would have a two hour heads-up before he had to move his vehicle.

Here’s how the Raspberry Pi comes into play:

“I used a Raspberry Pi with the Camera Module and OpenCV as a motion detector,” Naulty explains, rattling off the long list of tech that went into creating Meter Maid Monitor. “The camera monitors traffic and takes photos. The pictures are uploaded to AWS, where an EC2 instance running the TensorFlow supervised learning platform does the image recognition. I’ve trained it to recognise Meter Maid cars. Finally, if there’s more than a 75 percent chance of the car being a Meter Maid, it sends me a text message using Twilio, so I can move my car before I get a ticket.”

If this all feels a bit nefarious and subversive to you, hopefully you can at the very least appreciate John’s clever use of technology. Either way, if you want to see his code for the Raspberry Pi and for the AWS instance, head on over to his GitHub repo for this project. If you have any other smart ideas for using Raspberry Pi to make city parking more bearable, let’s hear ’em!