Simple low cost Digital Gear Indicator

Are you looking for A digital Gear Indicator that you can use to replace your old school individual indicators on your motorcycle. Guess what!, You find the right place. Ironically, my old speedometer visual indication of a gear was individual. I updated my Suzuki Shogun 125cc small commuter motorcycle from Analog to Digital without having to rewire that will be troublesome at some point since I wanted for my items of upgrade to be a direct replacement to the old one. Unfortunately, some Digital speedometer like this one has no gear indicator on the LCD for it was really intended for scooters like Yamaha Mio sporty without changeable gears. And the fact that it uses speedometer cable in the first place where mine do not have a cable but instead a SPEED SENSOR that reads the transmission gear tooth and send signals to the speedometer speed input.

My original speedometer is shown with 1, 2 ,3 and 4, indicators, It has been 12 years since I've used that kind until I decided to customized my panel cluster to a more inspiring and gorgeous to look as I am traversing the road ahead by putting a fully digital display custom panel for my 17 year old motorcycle. The hard work pays dividend. Loving it every day, every week, and probably will be forever my display for an old school motorcycle.

The DIGITAL GEAR INDICATOR

There are too many available in the open market, from simplest all the way to microcontroller based gear indicator, samples of available at the open market

Other uses hall sensors, some uses switches on motorcycles without a gear indicator sensor.

But on most small motorcycle they uses the simplest gear sensor like this one.

HOW IT WORKS is just a straight forward common ground contact.

Gear Sensor works when a pin was in contact with those gold circled thing on the sensor. The contact has a continuity to ground and same thing happen to other contact when gear was selected. Small dot is the neutral.

The SIMPLEST BLOCK DIAGRAM

There is no fancy thing on a gear indicator for motorcycle. Almost all uses the ground contact and not the positive side of the electrical supply. It was the easiest and safest way to avoid shorting out the electrical supply. But the problem of this contact type was the tear and wear of the path of the contact that is why there are numerous times user thought they have a busted indicator light and or the speedometer gear light bulb was busted. But often neglect the tear and wear as the pointed objects move around the gear sensor. Often times they make a groove on that Sensor as shown

and the only way to reuse is to just sand and or flatten again the surface so that no groove will be visible for the

pointed contact get in touch with the brass circled dot. Do not worry about there might have some component attached to it, but there is NONE..

Now lets get this done.

The CIRCUIT

Heard of a logic IC. examples are AND GATE or NOR GATE or you been hearing 7 segment displays. The 74LS IC and or the CD4000 family, your choice. Either you use the 12 volts line and or the 5 volts line it does not matter.

But on this circuit i choose to use the 74LS Family logic IC. cheaper than the CD4000 family but more prone to static electricity failure so be careful on handling 74 series family IC.Maximum supply is just 12 volts and need a down converter from 12 volts which is the motorcycle supply and convert it to 5 volts only.