How to Use HC-SR05: Examples, Pinouts, and Specs

The HC-SR05 is an ultrasonic sensor used for distance measurement. It emits an ultrasonic wave and measures the time it takes for the echo to return, allowing it to calculate the distance to an object. This sensor is widely used in various applications such as robotics, obstacle avoidance systems, and distance measurement tools.

1. Power Supply: Connect the VCC pin to a 5V power supply and the GND pin to the ground.
2. Trigger Pin: Connect the Trig pin to a digital output pin on your microcontroller (e.g., Arduino).
3. Echo Pin: Connect the Echo pin to a digital input pin on your microcontroller.

• Ensure that the sensor is placed in a position where it has a clear line of sight to the object being measured.
• Avoid placing the sensor near sources of ultrasonic noise, as this can interfere with measurements.
• Use a stable power supply to ensure accurate readings.
• Implement proper error handling in your code to manage cases where no echo is received.

// Define pins for the HC-SR05 sensor
const int trigPin = 9;
const int echoPin = 10;

// Define variables for duration and distance
long duration;
int distance;

void setup() {
  // Initialize serial communication at 9600 baud rate
  Serial.begin(9600);
  
  // Set trigPin as OUTPUT and echoPin as INPUT
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}

void loop() {
  // Clear the trigPin by setting it LOW
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  
  // Set the trigPin HIGH for 10 microseconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  // Read the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);
  
  // Calculate the distance
  distance = duration * 0.034 / 2;
  
  // Print the distance on the Serial Monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");
  
  // Wait for 60 milliseconds before the next loop
  delay(60);
}

1. No Echo Received: The sensor might not receive an echo if the object is too far or too close, or if the object is not within the sensor's measuring angle.
2. Inaccurate Readings: This can be caused by electrical noise, unstable power supply, or incorrect sensor placement.

• No Echo Received: Ensure the object is within the sensor's range (2cm to 400cm) and within the 15-degree measuring angle. Check connections and ensure the sensor is powered correctly.
• Inaccurate Readings: Use a stable power supply and ensure the sensor is placed in a stable environment. Avoid placing the sensor near sources of ultrasonic noise. Implement averaging in your code to smooth out readings.

By following these guidelines and best practices, you can effectively use the HC-SR05 ultrasonic sensor in your projects for accurate distance measurement.