1Pcs Ultrasonic Module HC-SR04 SR04 4Pin Distance Measuring Transducer Sensor Description/Features: Stable performance and precise distance measurement High precision module, blind spot (2cm) ultra close Wiring methods, VCC, trig (control end), echo (receiver end), GND Usage: If a control port sends a high level of 10US or more, you can wait for the high level output at the receiving port. Once there is an output, you can start the timer timer. When this port becomes low, you can read the value of the timer. This is the time for this distance measurement, and then the distance can be calculated. This continuous cycle measurement can reach the value of your mobile measurement Module working principle: (1) Using IO triggered ranging to provide a high-level signal of at least 10us; (2) The module automatically sends 8 40kHz square waves and detects whether there is a signal return; (3) There is a signal return, and a high level is output through IO. The duration of the high level is the time from the emission to the return of the ultrasonic wave. Test distance=(High level time x Sound speed (340M/S))/2; Specifications: Type: B-HC-SR04 SR04 4Pin Operating voltage: DC5V Quiescent current: less than 2mA Level output: high 5V Level output: bottom 0V Sensing angle: no more than 15 degrees Detection distance: 2cm-450cm High precision: up to 0.3cm Due to different batches, there may be differences in product appearance and printed text, which will not affect use. Material: PCB colour: As Shown Package Contents: 1 x module