Use the IO TRIG port to trigger telemetry. The module requires a minimum of 10 µs high-level TTL pulse signals. It automatically generates an 8-cycle, 40 kHz square wave output and detects returning echo signals. When a signal is received, it outputs a high-level TTL pulse via the IO ECHO port. The duration of this high-level pulse corresponds to the time between ultrasonic transmission and echo reception. Distance is calculated as: (pulse duration × speed of sound in air [340 m/s]) / 2. Static current (max): 2 mA Output voltage level: 5 V (high), 0 V (low) Detection range: 2 cm to 450 cm Accuracy: ±2 mm Module Main Technical Parameters: Operating voltage: 5 V DC Static current: < 2 mA Output signal: TTL-compatible, 5 V high level, 0 V low level Beam angle: ≤ 15 degrees Sensing distance: 2 cm – 450 cm Accuracy: up to ±3 mm Input trigger signal: 10 µs TTL pulse Echo signal: TTL pulse-width output Pin configuration: VCC (5 V power supply), TRIG (trigger input), ECHO (echo output), GND (ground) Package includes: 5 × HC-SR04 Ultrasonic Distance Sensor Modules for Arduino Note: Measurements are manually taken; allow for ±1–3 cm tolerance. Slight color variation may occur due to lighting and display differences.