How to Use Human Presence Sensor: Examples, Pinouts, and Specs

The Grove - Human Presence Sensor (AK9753) is a sophisticated device designed to detect the presence of a human in a specific area. Utilizing advanced infrared technology, it senses body heat or motion, making it ideal for a variety of applications. This sensor is commonly used in security systems, smart home automation, energy-saving systems, and interactive installations.

1. Power Supply: Connect the VCC pin to a 3.3V or 5V power supply and the GND pin to the ground.
2. I2C Communication: Connect the SDA and SCL pins to the corresponding I2C pins on your microcontroller (e.g., Arduino UNO).
3. Interrupt (Optional): If you want to use the interrupt feature, connect the INT pin to a digital input pin on your microcontroller.

• Power Supply: Ensure that the power supply voltage is within the specified range (3.3V - 5V) to avoid damaging the sensor.
• I2C Address: The default I2C address for the AK9753 is 0x64. Make sure this address does not conflict with other I2C devices on the same bus.
• Placement: For optimal performance, place the sensor in a location where it has a clear line of sight to the area you want to monitor.
• Interference: Avoid placing the sensor near sources of heat or direct sunlight, as these can interfere with its ability to detect human presence accurately.

#include <Wire.h>

#define AK9753_I2C_ADDRESS 0x64

void setup() {
  Serial.begin(9600);
  Wire.begin(); // Initialize I2C communication
  // Configure the sensor (if needed)
  // For example, setting up the interrupt pin
  pinMode(2, INPUT); // Assuming INT pin is connected to digital pin 2
}

void loop() {
  Wire.beginTransmission(AK9753_I2C_ADDRESS);
  Wire.write(0x00); // Register address to read data
  Wire.endTransmission();
  Wire.requestFrom(AK9753_I2C_ADDRESS, 2); // Request 2 bytes of data

  if (Wire.available() == 2) {
    int data = Wire.read() << 8 | Wire.read();
    Serial.print("Presence detected: ");
    Serial.println(data);
  }

  delay(1000); // Wait for 1 second before next reading
}

1. No Detection: The sensor does not detect any presence.

   • Solution: Ensure the sensor is powered correctly and the connections are secure. Check for any obstructions in the sensor's line of sight.

2. False Positives: The sensor detects presence when there is none.

   • Solution: Avoid placing the sensor near heat sources or in direct sunlight. Adjust the sensor's sensitivity if possible.

3. I2C Communication Failure: The microcontroller cannot communicate with the sensor.

   • Solution: Verify the I2C connections (SDA and SCL). Ensure the I2C address (0x64) is correct and not conflicting with other devices.

• Check Connections: Ensure all connections are secure and correctly oriented.
• Power Supply: Verify that the power supply voltage is within the specified range.
• I2C Scanner: Use an I2C scanner sketch to confirm the sensor's address and ensure it is detected on the I2C bus.
• Sensor Placement: Reposition the sensor to avoid interference from heat sources or direct sunlight.

By following this documentation, users can effectively integrate the Grove - Human Presence Sensor (AK9753) into their projects, ensuring reliable and accurate human presence detection.