Infrared Reflectance Sensor

This IR reflective sensor utilizes a TCRT5000 to detect color and distance. It emits IR and then detects if it receives the echo. This sensor is often used in line following robots, auto data logging on utility meters because this module can sense if a surface is white or black.

The measuring distance range from 1mm to 8mm and the central point is about 2.5mm. There is also an onboard potentiometer to adjust the sensitivity.

The infrared diode will emit infrared continually when the module is connected to power, when the emitted infrared light has not been reflected or the strength is not big enough,the triode will in the off state, at this time, D0 output logic LOW and the signal indicate LED off.

Features:

Supply Voltage: 3.3V~5V
Detect Distance: 1mm-8mm (optimal 2.5mm)
Digital Output: HIGH when objects detected
On-board Indicator LED: Shows when detection triggered
Sensitivity: On-board potentiometer to adjust
Driver: On-board LM393 chip
Board Size: 28mm long x 15mm wide

Vcc: 3.3 to 5 V DC Supply Input
Gnd: Ground Input
D0: Output that goes low when obstacle is in range
A0: Output Analog signal
Power LED: Illuminates when power is applied
Obstacle (Output) LED: Illuminates when obstacle is detected
Sensitivity Adjust: Adjust detection distance. CCW decreases distance. CW increases distance

Arduino Reflectance Sensor Connection - Analog

Connecting your Reflectance Sensor Module to the Arduino requires only three connections. Power (+5v), Ground and a connection between the A0 ports on both the Arduino and the Reflectance Sensor.

Arduino UNO R3 Code

The Arduino UNO R3 code to measure the output of the Infrared Reflectance Sensor is included as part of the examples provided in the Arduino IDE.

Launch the AnalogReadSerial example and upload the sketch to your Arduino.

After uploading the sketch, user the Serial Monitor (Ctrl+Shift+M or Tools...Serial Monitor) and the analog relative readings will be displayed as the sensor data changes.

/*
AnalogReadSerial
Reads an analog input on pin 0, prints the result to the serial monitor.
Attach the center pin of a potentiometer to pin A0, and the outside pins to +5V and ground.
*/

// the setup routine runs once when you press reset:
void setup() {
  // initialize serial communication at 9600 bits per second:
  Serial.begin(9600);
}

// the loop routine runs over and over again forever:
void loop() {
  // read the input on analog pin 0:
  int sensorValue = analogRead(A0);
  // print out the value you read:
  Serial.println(sensorValue);
  delay(1);        // delay in between reads for stabilty
}

Arduino Reflectance Sensor Connection - Digital

int LED = 13; // Use the onboard Uno LED
int isObstaclePin = 2;  // This is our input pin
int isObstacle = HIGH;  // HIGH MEANS NO OBSTACLE

void setup() {
  pinMode(LED, OUTPUT);
  pinMode(isObstaclePin, INPUT);
  Serial.begin(9600);  
}

void loop() {
  isObstacle = digitalRead(isObstaclePin);
  if (isObstacle == LOW)
  {
    Serial.println("Obstacle!! Obstacle!!");
    digitalWrite(LED, HIGH);
  }
  else
  {
    Serial.println("All Clear");
    digitalWrite(LED, LOW);
  }
  delay(200);
}

TCRT5000 Sensor Specification Datasheet

The sensor used on the Infrared Reflectance is the TCRT5000. Full product specification on the sensor are available in PDF format.