Hi guys, I'm building a line follower. I've used 5 analog IR sensors. I get high values on a black surface and low values on white. I'm facing some trouble with analog IR sensors while using different power supplies. Here's a screen shot of actual sensor data(picture attached):
These are the readings obtained from the sensors with different power supplies. These sensor readings were taken keeping the line follower at a fixed position over the line. I suspect the unusual sensor readings for the second case is due to irregular voltage spikes. Can somebody please suggest a solution? Any rectifier circuit that I need to add? I wish to use both batteries as well as the battery eliminator for providing power(not simultaneously).
I've used a 7805 power regulator with two 10uF 63V capacitors for regulated 5V supply. One capacitor is connected between 7805's input and Gnd, and other is connected between 7805's output and Gnd.
Here's a description of analog IR sensor, commonly used in line following applications. http://www.pololu.com/catalog/product/958
They give an analog output depending upon how much black or white surface they see. S1 to S5 are the readings of 5 sensors I'm using in my bot. Line is the weighted mean of the 5 sensor readings(this column may be ignored). I'm not using the pololu ones, but a similar circuit with tweaked resistances and locally available IR sensor and emitter. When a sensor is over a black surface, it gives high values and when on white, gives low values. I connected the sensors to analog inputs of a arduino, which interprets the sensor input in the range 0 to 1000.