GP2Y0D810 Infrared Sensor

Introduction

Infrared sensors are a form of distance sensors. They tend to be more susceptible to inaccuracies. This is because they send out infrared light and wait for the light to tell distance. Certain colors, especially black, absorb some of the infrared light and may return a false reading.

This was tested on a variety of objects that were what would be considered black. A reading was obtained from almost all of the tested objects, although the distance returned varied. There was one black object that the sensor could not detect at all. The moral of this story is do not rely solely on infrared sensors for distance detection. Redundancy is key when working on robots.

For the GP2Y0D810 sensor, Pololu makes a breakout board that has three pins on it: VIN, GND, and OUT.

Schematic

The important thing to note is that the OUT pin goes to an analog pin.

Coding

This sensor was used on a robot that did not want to get too close to objects, so when the analog value hit a given number that meant that the robot was within 10cm of an object on the side that the sensor faced. Knowing the value, the robot would be able to respond accordingly.

Below is the code explaining how the sensor works. The value that is given was found by holding objects over the sensor and lowering them until the built-in LED would light up. The value was found to be consistent.

int irPin = A0;
int sensorValue = 0;

void setup() {
  Serial.begin(9600);
}

void loop() {
  sensorValue = analogRead(irPin);
  
  //check for value of 85 or less for distance testing
  if (sensorValue <= 85) {
    Serial.println("Too close");
  }
  
  delay(1000);
}

This is just a very simple use of the infrared sensor, but an effective one depending on the purpose.