How to Use HDJD-S822-QR999: Examples, Pinouts, and Specs

The HDJD-S822-QR999, manufactured by Avago Technologies, is an infrared emitter and detector module designed for proximity sensing and object detection applications. This module integrates an infrared LED and a phototransistor, enabling it to emit and detect infrared light. Its compact design and reliable performance make it ideal for non-contact sensing in a variety of applications.

• Proximity sensing in consumer electronics
• Object detection in industrial automation
• Gesture recognition systems
• Line-following robots
• Security systems and intrusion detection

The HDJD-S822-QR999 module typically has four pins. Below is the pinout and description:

1. Power Supply: Connect the VCC pin to a regulated power supply (2.7V to 5.5V) and the GND pin to the ground of the circuit.
2. Infrared LED: Use a current-limiting resistor in series with the IR LED Anode pin to prevent excessive current through the LED. The resistor value can be calculated using Ohm's Law: [ R = \frac{V_{supply} - V_{LED}}{I_{LED}} ] where ( V_{LED} ) is the forward voltage of the LED (typically 1.2V) and ( I_{LED} ) is the desired current (e.g., 20mA).
3. Phototransistor Output: Connect the Phototransistor Collector pin to a pull-up resistor and then to the power supply. The output signal can be read as a voltage drop across the pull-up resistor, which changes based on the amount of infrared light detected.

• Ambient Light Interference: To minimize interference from ambient light, consider using modulation techniques (e.g., pulsing the IR LED at a specific frequency) and filtering the phototransistor output.
• Distance and Alignment: Ensure proper alignment between the emitter and the object to be detected for accurate sensing. The detection range depends on the object's reflectivity and the intensity of the emitted IR light.
• Heat Dissipation: Avoid exceeding the maximum current rating of the IR LED to prevent overheating and damage.

Below is an example of how to use the HDJD-S822-QR999 with an Arduino UNO for proximity sensing:

• Connect VCC to the Arduino's 5V pin.
• Connect GND to the Arduino's GND pin.
• Connect the IR LED Anode to a digital pin (e.g., D3) through a 220Ω resistor.
• Connect the Phototransistor Collector to an analog input pin (e.g., A0) with a 10kΩ pull-up resistor.

// Define pin connections
const int irLedPin = 3;       // Digital pin connected to IR LED
const int sensorPin = A0;     // Analog pin connected to phototransistor

void setup() {
  pinMode(irLedPin, OUTPUT);  // Set IR LED pin as output
  Serial.begin(9600);         // Initialize serial communication
}

void loop() {
  digitalWrite(irLedPin, HIGH);  // Turn on the IR LED
  delay(10);                     // Allow time for the LED to stabilize

  int sensorValue = analogRead(sensorPin);  // Read phototransistor output
  Serial.print("Sensor Value: ");
  Serial.println(sensorValue);              // Print the sensor value

  digitalWrite(irLedPin, LOW);   // Turn off the IR LED
  delay(100);                    // Wait before the next reading
}

1. No Output Signal from Phototransistor

   • Cause: Incorrect wiring or insufficient IR light.
   • Solution: Verify the connections and ensure the IR LED is emitting light. Check the current-limiting resistor value.

2. Inconsistent Readings

   • Cause: Ambient light interference or poor alignment.
   • Solution: Use modulation techniques to filter out ambient light and ensure proper alignment between the emitter and the object.

3. Short Detection Range

   • Cause: Low IR LED intensity or low object reflectivity.
   • Solution: Increase the current through the IR LED (within safe limits) or use a more reflective object.

Q1: Can the HDJD-S822-QR999 detect transparent objects?
A1: Transparent objects may not reflect sufficient infrared light for detection. Use reflective or opaque objects for best results.

Q2: What is the maximum detection range of this module?
A2: The detection range depends on the object's reflectivity and the IR LED intensity. Typically, it ranges from a few centimeters to several meters.

Q3: Can this module be used outdoors?
A3: Yes, but ambient sunlight may interfere with its performance. Use modulation techniques to improve reliability in outdoor environments.