HC-SR04 Ultrasonic Distance Sensor – High-Precision Range Finder Module (2cm to 400cm)

Technical Details

• Working Frequency: 40kHz ultrasonic pulse prevents interference from common environmental noise.

• Input Trigger: Requires a 10-microsecond high-level pulse to initiate the measurement cycle.

• Output Calculation: Distance = (High Level Time × Velocity of Sound (340M/S)) / 2.

• Transducer Type: Independent Ultrasonic Transmitter and Receiver sensors for simultaneous signal processing.

• Quiescent Current: Ultra-low standby current of less than 2mA ensures battery efficiency in portable projects.

• Logic Level: 5V TTL logic output; high-level duration corresponds directly to the distance measured.

• Signal Stability: Internal control circuitry filters out false echoes to ensure stable readings even in complex indoor environments.

• Maximum Range Timing: If no obstacle is detected, the Echo pin stays high for approximately 38ms before resetting.

• Temperature Compensation: While accurate, results can be further refined by factoring in ambient temperature for sound speed adjustments.

• PCB Finish: High-quality green solder mask with clear pin labeling for error-free wiring.

• Response Time: Fast measurement cycle allows for high-frequency polling, ideal for moving obstacle avoidance.

• Directional Focus: Narrow beam angle of 15 degrees allows for targeted sensing without detecting side walls.

• Mounting Holes: Includes pre-drilled holes for secure attachment to brackets or robot frames.

• Robust Construction: Piezoelectric ceramic transducers are resistant to vibrations and common mechanical shocks.

• Environmental Tolerance: Operates effectively in humidities up to 90% (non-condensing).

Prototyping and Engineering Tips from Robogears

• 9V Battery Use: When powering your project with a 9V battery, ensure the HC-SR04 is connected to the Arduino's 5V regulated output. Connecting 9V directly to the VCC pin will destroy the sensor.

• 18650 Cell: For stable readings in mobile robots, power the sensor through a 5V Boost Converter when using a single 18650 cell, as the sensor requires a steady 5V to maintain accuracy.

• Resistor Tip (Raspberry Pi): Since the Echo pin outputs 5V, use a 1k and 2k resistor voltage divider to step the signal down to 3.3V before connecting it to a Raspberry Pi's GPIO pin.

• Related Products: We recommend pairing this sensor with our HC-SR04 Mounting Brackets, SG90 Servo Motors (for scanning), and 2WD Robot Chassis Kits.

Package Includes

• 1 x HC-SR04 Ultrasonic Distance Sensor Module.

Disclaimer Image is for illustration purpose only. Avoid touching the ultrasonic transducers during operation to prevent interference and maintain long-term calibration accuracy.