Speed Heads-Up Display Uses GPS Tracking

Inspiration comes to us from all different directions, and after noticing that he could read a piece of paper reflected on his car’s front window, hacker “ludektalian” decided to make a heads-up display using the same principle.

His DIY device uses a u-blox NEO-M8 GPS module to tell how fast the car is going, along with a three-digit (cut down four-digit) LED matrix display to show vehicle speed in kilometers per hour.

An Arduino Pro Mini is the brains of the operation, and a photoresistor allows the system to vary its brightness depending on ambient conditions. Since it uses a GPS module for speed sensing, it’s mostly self-contained, requiring only a 12VDC input from the vehicle to keep it powered.