The HC-SR04 ultrasonic sensor uses sonar to determine the distance to an object. It offers excellent non-contact range detection with high accuracy and stable readings from 2 cm to 400 cm with an accuracy of 3mm. Not affected by sunlight or black material like optical rangefinders are (although acoustically soft materials like cloth can be difficult to detect). The HC-SR04 comes complete with an integrated ultrasonic transmitter and receiver.
Product Specifications:
Working Voltage: 5 VDC
Static current: Less than 2mA.\
Output signal: Electrical frequency signal, high level 5V, low level 0V
Sensor angle: Not more than 15 degrees
Detection distance: 2cm - 400cm
Accuracy: Up to 3mm
Input trigger signal: 10us TTL impulse
Echo signal : Output TTL PWL signal
Item size: 44mm * 20mm * 15mm
Net weight: 11grams
Mode of connection:
VCC: 5V DC supply input
Trigger (T): Control signal input (10us TTL impulse)
Echo (R): Echo signal output, duration is time from transmit to receive
Ground GND: Ground wire
HC-SR04 Ultrasonic Module Operation:
Supply module with 5V, the Echo (R) output will be 5V while obstacle is in range, or 0V if it is not. Duration of Echo signal is used to calculate distance to object (see below).
Use the IO port Trigger (T) to trigger ranging by applying a 10 us high level (TTL) trigger signal. The module will send an output square wave signal through its output acoustic transducer automatically, and will test if there is any signal returned to its input acoustic sensor.
If there is an acoustic signal returned, The ECHO (R) IO port will have a high level signal. The duration of the high level signal is the time from transmit to receive using the ultrasonic transducers.
Distance to object from module = Duration of ECHO (R) high level signal * sound velocity (340m/s) / 2
Package includes:
5 x HC-SR04 Ultrasonic Distance Sensor Module