~ Vimal, Abilash, Prabha
We had learnt to interface a toy DC motor with the arduino platform. The idea is to design a sensor controlled vehicle which navigates based on the intensity of the light which falls on it.
We used a LDR(Light Dependent Resistor) as a sensor element for the project. The analog value of intensity of the light falling on it is measured and it ranges from 0 – 1024 (10 bit resolution limitation of arduino). We used a dual H bridge IC named L293D to actuate the motor. To get the desired torque, we have selected a geared motor with 300 RPM @ 12VDC.
For this task we used only one geared motor and one half of the dual H Bridge. For initial prototyping we used the breadboard, the enable pin of one half of the IC is connected to 5VDC, two IOs are assigned namely 4 and 7 to control the outputs of the IC. The LDR is connected to the analog pin A0. The LDR circuit is designed as a voltage divider circuit. The analog value obtained from the task is compared continuosly with the threshold limit of 950. If the value is changed the motor will rotate in clockwise direction else in anticlockwise direction.