Ultrasonic sensor HC-SR04 operating in the range from 2 cm to 200 cm with a special bracket for mounting. It is powered with the voltage of 5 V. The output is a signal whose duration is proportional to the measured distance.
- Supply voltage: 5 V
- Average current consumption: 15 mA
- Measuring range: from 2 cm to 200 cm
- Output: frequency signal
- Working frequency: 40 kHz
- The kit includes the mounting bracket
- Dimensions: 45 x 20 x 15 mm
Details in the documentation.
Method of application
To begin the measurement, you must specify the voltage pulse on the TRIG pin (5V high status) during 10 us. The module measures distance using sound waves with a frequency of 40 kHz. To the microcontroller sent is a signal which distance depends on the duration of high status and it can be calculated using the formula:
test distance = (high level time × velocity of sound (340m/s) / 2
- test distance - the measured distance
- high level time - duration of the high status
- velocity of sound - velocity of propagation of sound waves in air is 340 m/sec
In short, to get the result in cm, use the formula:
distance [cm] = (high level time [us] * 34) / 1000 / 2
The measurement procedure is shown in the figure below.