HC SR04 ultrasonic sensor is a popular sensor used in areas where distance is measured, and objects are senses. On its front, the sensor has two eyes which are similar to projects. These two eyes function as the ultrasonic receiver and transmitter. This ultrasonic sensor works on the assumption that distance is a product of speed and time. 

When the ultrasonic transmitter sends an ultrasonic wave, the wave travels in the air, and after encountering any obstruction, it reflects the sensor. The ultrasonic receiver then observes the reflected wave. The module has an inbuilt circulatory system which calculates the time taken by the wave to come back and turn to an echo. The distance is then calculated using a microprocessor or microcontroller. 

HC SR04 datasheet

According to its datasheet, some of the main specs of the sensor are:

  • Operating voltage of +5V
  • Operating frequency of 40Hz
  • Conducting current of less than 15mA
  • It covers a measuring angle of 150
  • The distance measured practically is 2cm-80cm
  • The distance measured theoretically is 2cm-450cm

The following are the key application areas for the sensor:

  • Detecting and avoiding obstacles with robots
  • It measures the depth of places like pits and wells.
  • Rotating the sensor to map the objects surrounding it
  • Measuring the distance in a wide range of 2cm-400cm

HC SR04 pinout

The sensor has four pinouts. The Vcc pin is the first one, and it powers the sensor. The second one is the trigger pin, and it initializes the measurement. The third pin is the echo pin, and the fourth one is the ground pin connected to the system’s ground.

Have a look at the pinout diagram below. 

HC SR04 Equivalents and Replacement Details

As an Ultrasonic Sensor Noncontact Range Detection, other sensors that measure distance and sense objects like HC SR04 ultrasonic sensor are the Analog distance sensor, the IR sensor pair, IR sensor module, and the US transmitter Receiver pair. 

Leave a comment