TCS3200 chip is designed to detect the colour of light incident on it. It has an array of photodiode (a matrix of 8x8, so a total 64 sensors). These photodiodes are covered with three type of filters. Sixteen sensor have RED filter over them thus can measure only the component of red in the incident light. Like wise other sixteen have GREEN filter and sixteen have BLUE filter. As you should know that any visible colour can be broken into three primary colours. So these three type of filtered sensors helps measure the weightage of each of primary colours in incident light. The rest 16 sensors have clear filter.

TCS3200 converts the intensity of incident radiation into frequency. The output waveform is a 50% duty cycle square wave. You can use the timer of a MCU to measure period of pulse and thus get the frequency.

The output of TCS3200 is available in single line. So you would ask how we get the intensity of RED,GREEN, BLUE and CLEAR channels? Well it has two inputs S2 and S3 that is used to select the sensor whose output need to be made available on the out line.