TCS230 Colour Sensor Module

The TCS230 senses color light with the help of an 8 x 8 array of photodiodes. Then using a Current-to-Frequency Converter the readings from the photodiodes are converted into a square wave with a frequency directly proportional to the light intensity. Finally, using any Micro we can read the square wave output and get the results for the color.

Quick Spec

• High-Resolution Conversion of Light Intensity to Frequency
• The Break-out board has TCS230 color sensor
• Single-Supply Operation (2.7 V to 5.5 V)
• Nonlinearity Error Typically 0.2% at 50 kHz
• Four bright white LED, on-board, can illuminate the object which does not emit light itself
• Pins S1 S2 S3 S4 can be used as the pull-up or pull-down resistors on board.
• PCB Size: 23mm X 30mm

Background

This breakout board is a color sensor based on TAOS TCS230 programmable color light to frequency converter which combines configurable silicon photodiodes and a current –to-frequency convertor on single monolithic CMOS integrated cicuit.

The light-to-frequency converter reads 8X8 array of photodiodes, each array could filter red, green, blue light or clear from light source via two control pins(S2,S3) and output a square wave(50% duty cycle) with frequency directly proportional to light intensity(irradiance). The full-scale output frequency can be scaled via two control input pin(S0,S1). Digital inputs and digital output allows direct interface to a microcontroller or other digital logic circuitry.

Signal Description

Circuit Diagram

Working Principle

As we know, according to the RGB color model, a broad array colors is produced by red green and blue light added together in various ways. In other word, if we know the RGB data which constitutes different kind of color, we can get the certain color we test. With a certain color filter is selected(e.g red filter), TSC230 color sensor allows red light to get through alone and prevent other color green and blue light, so we can get the intensity of the red color. Blue and green light of intensity can be got in the same way.

TCS230 includes 8X8 array of photodiodes, 16 photodiodes have blue filters, 16 photodiodes have green filters, 16 photodiodes have green filters and 16 photodiodes are clear with no filters. With the different combination of S2 and S3, we can choose different type of color filter The full-scale output frequency can be scaled via two control input S0 and S1, by which we can output the different frequency coefficient (100%, 20%, 2%).

Arduino Software and Connections

The four white highlight LEDs in the surrounding are providing a source constant light. The OE = OUTPUT ENABLE (on this board it is marked as EO) connects to GND which means the module is always enabled. The OUT(Signal pin) is a square wave output signal (50% duty cycle) with frequency directly proportional to light intensity (irradiance). Most Arduino boards have two external interrupts: numbers 0 (on digital pin 2) and 1 (on digital pin 3). So we connect OUT to D2 for counting the square wave frequency using external interrupt 0.

Resources

• Sample Code
• TCS230 Datasheet
• Example by DF Robot

Shipping List

• 1 x TCS230 Colour Sensor Module