DIGITAL SPEEDOMETER

A digital speedometer is gadget commonly found in automobile and used to measure the instantaneous speed of a vehicle. But what people simply refer as digital Speedometer is a set of instrumentation, including the speedometer, that displays a digital readout rather than with the traditional analog gauges. Although mostly fond in vehicles it can be used to to measure any objects’ speed which has specific speed.

In a vehicle it measures the rotational speed of the wheel. 

There are two types of Speedometers namely Eddy Current Speedometer and Electronic speedometer. The later one is the modern one from those two.

When it compared to old analogue speedometers this gadget doesn’t employ a moving pointer to display the value instead it has a screen which will displays the most accurate value of speed. The digital speedometer uses a micro controller, an LCD screen and some commonly available components

A Hall-effect sensor is used to measure the rotation speeds of the wheel. The Hall-effect sensor attaches to the vehicle near its periphery and a fixed distance from the wheel's axle. When the wheel rotates, a permanent magnet attached to the wheel passes the sensor, activating it and generating one short pulse for each revolution of the wheel.