It is a bot that senses the light & follows it. A user can shine a flashlight at its front and it will respond by following the light source. This robot uses a microcontroller for processing the sensor readings and responds by controlling the motors .
The robot has two light detection sensors which are prepared with LDRs (light dependent resistors). The sensitivity of the sensors can be set by using the potentiometer on each sensor circuit. Light follower robot is activated with light. The robot moves as long as it detects the light. It has two 6 V geared 60 rpm DC motors, two wheels and a caster ball wheel,l293d motor driver. The motor control part of the circuit was prepared with ARDUINO Uno and motor driver.
Photo resistors, also known as light dependent resistors (LDR), are light sensitive devices most often used to indicate the presence or absence of light, or to measure the light intensity. In the dark, their resistance is very high, sometimes up to 1MΩ, but when the LDR sensor is exposed to light, the resistance drops dramatically, even down to a few ohms, depending on the light intensity. LDRs have a sensitivity that varies with the wavelength of the light applied and are nonlinear devices. They are used in many applications but are sometimes made obsolete by other devices such as photodiodes and phototransistors.
APPLICATION They do not have a specific applications, it is up to you and your imagination to give an application for them.