Introduction

In this project we are going to create a speedometer. Speedometers are instruments that are used in vehicles to indicate the speed of vehicles. In the speedometer, the speed is shown by a pointer;(the pointer move along a scale to show the speed the car is moving at).

To build this project we need:

1. Unda Xplora Kit
2. Motor
3. Potentiometer
4. Jumper Wires  and Breadboarding Jumper Wires

Let’s build the Speedometer Project

Place the motor and potentiometer  on the breadboard.

Connect a jumper wire from 5V pin to the third pin of the potentiometer.

Connect a jumper wire from GND pin to the  top breadboard negative rail and then connect from breadboard negative rail to the first pin of the potentiometer using breadboarding jumper wire.

Connect a jumper wire from analog pin A4 to the middle pin of the potentiometer.

Connect a jumper wire from  digital pin D10 to the positive pin of the motor and then connect a jumper wire from negative rail to the negative pin of the motor.

In the project window select the Load option to run the Projec.t. Once the project has been uploaded  go to the Play Section. Turn the knob gradually in the clockwise direction and observe what happens to the motor and  the Play Section window.  Turn the knob gradually in the  anti-clockwise direction and observe what happens  in both the Play section window and to the motor.

What did you observe?

Once you have uploaded the project and head over to the play section, you will realize that a value is displayed on the screen. When the value is at zero, the motor is off as well and thus does not spin.

As you turn the knob anticlockwise, the displayed on the screen begins to gradually increase from zero. As this value increases you realize that the motor turns on and begins to spin. The speed at which the motor rotates also gradually increases as the value keeps increasing.

This project works in a similar manner to the actual speedometer. The increase of the speed of the motor is similar to an increase in the speed of the motor. These value of the speed is then displayed on the dashboard just as we display the value on the Unda Xplora’s screen.

Try turning the knob in a clockwise direction and observe what happens.