Vassilis Papanikolaou has made a nice Motorcycle Universal Gear Indicator Circuit which allows you to easily see what gear you are in. I am now curious how my first motorcycle indicated the current gear, there was a single 7 segment display between the speedometer and tachometer. I am guessing that it was probably all mechanical but who knows, it might have been this complex!
Thanks sending it in Vassilis.
“The main circuit is based on an AVR ATTINY25/45/85 microcontroller, which reads the signals of the two Hall sensors and the neutral switch and outputs the current gear number to a 7-segment LED indicator, through a 4026 counter/decoder.”