Hacker Gagandeep Singh has developed a do-it-yourself project for designing a grid of LED lights on the rear window of a vehicle without obstructing the view from the rear-view mirror. Singh is interested in providing feedback to drivers that don’t pay attention to the rules of the road. Using his Volkswagon Polo as the guinea pig for the project, Singh created plans for a 40 x 16 LED matrix display with LED lights that allowed two centimeters of space in between each LED in order to still see out the rear window. He then used a strip of wood to accurately measure out the distance between the LED lights and spent the next two days soldering the lights into the full matrix display.
After attaching all the wiring at the bottom of the display and making sure the matrix lit up, Singh attached the matrix to the interior of the Polo and connected it up to a AT89C51 micro-controller. This controller allows Singh to design patterns as well as messages and watch them display in the rear window. For instance, Singh could ask a tailgating driver to back off his bumper while traveling down the highway. While entering messages into the controller is likely too much of a distraction while driving the automobile, the next stage in the project will enable updating the matrix through a Bluetooth connection on a mobile smartphone.
While others can follow Singh’s instructions in his Google slideshow detailing the entire process, it’s unlikely that this matrix would be adapted for the mass market. Abuses of the technology could easily lead to distracted drivers on the road as well as angry drivers if the matrix was used to display obscenities. In addition, any object that blocks the rear window at all would likely be frowned upon by lawmakers.