After acquiring five 4-character, 16 segment display modules that were too good to pass up, they were promptly deposited in the parts pile until [JF] was cajoled into building something by a friend.

Mechanical multi-segment displays have become quite a thing lately, and we couldn’t be more pleased about it. The degree of mechanical ingenuity needed to make these things not only work but … ...

My model uses the car's OBD-II port to connect to an Arduino microcontroller, which is programmed to display the car's speed on a 7-segment display. A fresnel lens is used to optically collimate ...