SR04 Datasheet | Elec Freaks

features : Ultrasonic ranging module HC - SR04 provides 2cm - 400cm non-contact measurement function, the ranging accuracy can reach to 3mm. The modules includes ultrasonic transmitters, receiver and control circuit. The basic principle of work: (1) Using IO trigger for at least 10us high level signal, (2) The Module automatically sends eight 40 k Hz and detect whether there is a pulse signal back. (3) IF the signal back, through high level , time of high output IO duration is the time from sending ultrasonic to returning. Test distance = (high level time×velocity of sound (340M/S) / 2, - Wire connecting direct as following: 5V Supply Trigger Pulse Input Echo Pulse Output 0V Ground Electric Parameter Working Voltage Working Current Working Frequency Max Range Min Range Measuring Angle Trigger Input Signal Echo Output Signal Dimension DC 5 V 15m A 40Hz 4m 2cm 15 degree 10u S TTL pulse Input TTL lever signal and the range in proportion 45- 20- 15mm Vcc Trig Echo GND Timing diagram The Timing diagram is shown below. You only need to supply a short 10u S pulse to the trigger input to start the ranging, and then the module will send out an 8 cycle burst of ultrasound at 40 k Hz and raise its echo. The Echo is a distance object that is pulse width and the range in proportion .You can calculate the range through the time interval between sending trigger signal and receiving echo signal. Formula: u S / 58 = centimeters or u S / 148 =inch; or: the range = high level time - velocity (340M/S) / 2; we suggest to use over 60ms measurement cycle, in order to prevent trigger signal to the echo signal. - Attention: - The module is not suggested to connect directly to electric, if connected electric, the GND terminal should be connected the module first, otherwise, it will affect the normal work of the module. - When tested objects, the range of area is not less than 0.5 square meters and the plane requests as smooth as possible, otherwise ,it will affect the results of measuring. .Elec...