Building a better… tennis ball?

If I had a nickel for every time I pulled the car into the garage, only to find I didn’t quite pull in far enough, and then have to get back in and pull the car forward another 6 inches… I wouldn’t quite have a quarter… But still, it’s 2016, it is totally unacceptable for this to happen even once!

The traditional method of solving this problem involves suspending a tennis ball from the ceiling of the garage such that it just barely touches the windshield of the car when it is pulled in far enough (if this method would meet your needs, and you want to know more, let Sonya McKinney explain). This plan has one glaring flaw for our usage though… My wife prefers to pull the car in nose first, while I prefer to back in. We drive a super sexy car, so the front and rear windshields have different offsets from their respective ends of the vehicle. So what are we to do? Hang two tennis balls? Come to a consensus on which way to park the car? No. It’s time for a needlessly over-engineered, WiFi-enabled solution.

Here’s the plan… We have a shelving unit that sits directly in front of the car. I’m going to mount an ultrasonic range finder at bumper height, and an LED strip across the second shelf. As the LEDs are individually addressable, the lights will move in from both edges until they meet in the middle, when the car is in the right spot. The strip will flash red if you go too far.

Here is highly detailed diagram of the goal:

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Where does the WiFi come in? I’m going to use an ESP8266 to drive things, and since it will know if the car is parked or not, that information can feed into my Home Assistant instance, which can then be used to make better automation decisions about whether someone is home or not.

Stay tuned for actual progress (part two will likely be getting the project on a breadboard and getting most of the code written). EDIT: Yes, this project has indeed stalled… Hope to be picking it up again shortly.

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