ULTRASONIC HC-SR04 Product features
Ultrasonic ranging module HC - SR04 provides 2cm - 200cm the ranging accuracy can reach to 3mm.
The module includes ultrasonic transmitter, receiver and control circuit.
The basic principle of work
• Using IO trigger for at least 10us high level signal,
• The Module automatically sends eight 40 kHz and detect whether there is a pulse signal back.
• 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).
Easy to Interface conversion boards avilable now ( PWM TO UART , OBSTACLE) - based on PIC microcontroller
• Obstacle Interface Board.
• UART & Obstacle Output Board.
Interfacing sensor Pins
-> 5V Supply
-> Trigger Pulse Input
<- Echo Pulse Output
-> 0V Ground
• Working Voltage DC 5 V
• Working Current 15mA
• Working Frequency 40Hz
• Max Range 200cm
• Min Range 2cm
• MeasuringAngle 15 degree
• Trigger Input Signal 10uS TTL pulse
• Echo Output Signal Input TTL level signal and the range in proportion
• Dimension 45*20*15mm
Pin discription of board
O/P=when obstacle detect out put pin go high.
TX=Gives serial out put.
example readings= R40
R42 varies according to the distance vary.