Interface TCS3200 Colour Sensor With Arduino

Introduction

The TCS3200 is a color sensor module that can detect and measure the intensity of red, green, blue, and clear (no color) light. It uses an array of photodiodes and an RGB filter to convert light into frequency signals, which can be read and processed by a microcontroller like Arduino.

Hardware Overview

Color Sensor: The TCS3200 color sensor has an array of photodiodes with filters for red, green, blue, and clear. These photodiodes are arranged in a grid, allowing the sensor to detect different colors by filtering light through the corresponding colored filters.

White LEDs: The TCS3200 sensor module usually comes with four white LEDs. These LEDs provide consistent illumination to the object whose color is being measured. Proper and consistent lighting ensures accurate color detection regardless of the ambient lighting conditions.

Working Principle

The color sensor uses a very basic principle of light to identify the color. You see white is made up of three primary colors which are Red, Green and Blue and each has different wavelengths. When light falls on a surface, depending on the material properties, it gets absorbed or reflected. That reflected light gets picked up by our eye and as a result, we can see colors.

Now let’s look at how the TCS3200 color sensor works, as you can see in the gif above, we have the color sensor and we are giving High and low signals to the S0 and S1 pins of the sensor module which sets the sensor to 20% frequency scaling. That means the sensor will operate at a 200 KHz frequency. In this mode, the duty cycle of the sensor will remain at 50% but the output frequency of the sensor will change according to the color value. The S2 and S3 pins are used to select the array of photodiodes and as you can see in the gif for each color that is visible to the sensor we will set the array to red green and blue filter one by one. If the color detected by the sensor matches the selected array of the sensor, the output frequency of the sensor will increase and for any other situations the output frequency mostly stays the same or you can see a minute variation in the output frequen

Application

• Color Sorting: Used in automated sorting systems to separate objects based on color.
• Color Detection: Identifying colors in products, artworks, or visual displays.
• Color Matching: Matching colors for quality control in manufacturing processes.
• Color Sensing in Robotics: Implementing color-based navigation or object detection in robotics.
• Color Measurement: Quantifying color parameters for scientific or industrial purposes.

Technical Specifications

• Single-Supply Operation (2.7V to 5.5V)
• High-Resolution Conversion of Light Intensity to Frequency
• Programmable Color and Full-Scale Output Frequency
• Power Down Feature
• Communicates Directly to 5V Microcontroller
• S0~S1: Output frequency scaling selection inputs
• S2~S3: Photodiode type selection inputs
• OUT Pin: Output frequency
• OE Pin: Output frequency enable pin (active low), can be impending when using
• Support LED lamp light supplement control

Pinout

• S0: Output frequency scaling selection pin.
• S1: Output frequency scaling selection pin.
• S2: Photodiode type selection pin.
• S3: Photodiode type selection pin.
• OUT: Output pin for frequency signals (connected to a microcontroller input).
• VCC: Power supply pin (usually 3.3V to 5V).
• GND: Ground pin.

Circuit Diagram

Programming With Arduino

Step 1: Select the appropriate board and port

• Go to Tools > Board and select your Arduino board (e.g., Arduino Uno).

• Go to Tools > Port and select the port to which your Arduino is connected.

Step 2: Upload the Code

• Copy the provided code into your Arduino IDE.

const int S0 = 8;
const int S1 = 9;
const int S2 = 10;
const int S3 = 11;
const int sensorOut = 12;

volatile int counter = 0; // Interrupt counter

void setup() {
  // Initialize pins
  pinMode(S0, OUTPUT);
  pinMode(S1, OUTPUT);
  pinMode(S2, OUTPUT);
  pinMode(S3, OUTPUT);
  pinMode(sensorOut, INPUT);

  // Set frequency scaling (HIGH for 20%)
  digitalWrite(S0, HIGH);
  digitalWrite(S1, HIGH);

  // Set photodiode type (HIGH for RGB)
  digitalWrite(S2, HIGH);
  digitalWrite(S3, HIGH);

  // Attach interrupt to sensor output pin
  attachInterrupt(digitalPinToInterrupt(sensorOut), countPulses, FALLING);

  // Start serial communication
  Serial.begin(9600);
}

void loop() {
  // Reset counter
  counter = 0;

  // Enable color sensing for 1 second
  delay(1000);

  // Calculate color frequency
  float frequency = counter / 2.0; // Assuming 50% duty cycle

  // Print frequency (for debugging)
  Serial.print("Color Frequency: ");
  Serial.print(frequency);
  Serial.println(" Hz");
}

// Interrupt service routine to count pulses
void countPulses() {
  counter++;
}

• Verify and upload the code to your Arduino board.

Step 3: Open the Serial Monitor

1. Connect your Arduino to the computer and upload the code.
2. Open the Serial Monitor in the Arduino IDE by going to Tools > Serial Monitor or pressing Ctrl+Shift+M.
3. Set the baud rate to 9600 in the Serial Monitor.