/Features: Stable performance and precise distance measurement High-precision module with ultra-close blind spot (2 cm) Wiring: VCC, Trig (control pin), Echo (receiver pin), GND Usage: Apply a high-level signal of at least 10 µs to the Trig pin to initiate measurement. The module sends ultrasonic pulses and outputs a high-level signal on the Echo pin upon detection. The duration of this high-level pulse corresponds to the time taken for the ultrasonic wave to travel to the target and back. Distance = (pulse duration × speed of sound in air (340 m/s)) / 2. Continuous measurements support real-time distance monitoring. Module working principle: (1) Triggered by an IO signal — provide a high-level pulse of ≥10 µs on the Trig pin; (2) Module automatically transmits eight 40 kHz ultrasonic pulses and detects echo return; (3) Upon echo detection, the Echo pin outputs a high-level signal whose duration equals the round-trip time of the ultrasonic wave. Specifications: Type: HC-SR04 4-pin ultrasonic sensor module Operating voltage: DC 5 V Quiescent current: < 2 mA Output level (high): 5 V Output level (low): 0 V Sensing angle: ≤ 15 degrees Detection range: 2 cm – 450 cm Accuracy: ±0.3 cm Note: Slight variations in appearance or labeling may occur between batches; these do not affect functionality. Material: PCB Color: As shown Package Contents: 1 × HC-SR04 ultrasonic sensor module