Rear Window LED Marquee


Robert Dunn soldered 480 red LEDs into a grid in the rear window of his truck:

The LED Sign itself is a 48×10 soldered together matrix of red LED’s. I soldered them together sparsely in a mesh so it could be mounted in the back window without losing rear visibility. The rows are controlled using a 4017 decade counter for POV. The columns are controlled using six 959 shift registers.

Input from the vehicle is recieved from the trailer light hookup through a cable and into the cab. The signal from the trailer lights hookup is connected to the arduino using optocouplers. The arduino can sense both turn signals and the lights using this setup. The 12v signal is regulated down to 5v for the optocoupler using 7805 voltage regulators. There was probably somewhere in the cab to get the turning signal input from, but it was easier to use the trailer hookup, although uglier.

Via Hackaday

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  1. He could make some side money by having it scroll messages across the back. “Eat at Joe’s”

  2. I’ve wanted to make that for a long time. Except mine would say KEEP RIGHT EXCEPT TO PASS for every time some jackass makes me pass them on the right.

  3. Since he’s got it connected as directionals/hazzards it’s legal. Anything else involving red lights other than directional or break lights is illegal in the US, so scrolling marquee signs are a good way to get yourself a ticket.

  4. cool way of using LED and that is what semiconductor technology has gave as LED and even the manufacturing of led are in boom that I am wondering the application of led is getting so vast that it is been used everywhere like in marketing with led signs or in lighting purpose or in decoration.

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