[tutorial] How to use the HC-SR04 Ultrasonic Sensor

Introduction

The HC-SR04 ultrasonic sensor uses sonar to determine distance to an object like bats or dolphins do. It offers excellent non-contact range detection with high accuracy and stable readings in an easy-to-use package. From 2cm to 400 cm (or 1” to 13 feet). It operation is not affected by sunlight or black material like Sharp rangefinders are (although acoustically soft materials like cloth can be difficult to detect). It comes complete with ultrasonic transmitter and receiver module.

In this tutorial you will learn how to use this sensor with the Arduino uno and print the distance from an object to the serial monitor.

What you will need

For this tutorial you will need:

• Arduino uno
• Breadboard
• HC-SR04 Ultrasonic Sensor

The Circuit

The connections are pretty easy, see the image above with the breadboard circuit schematic.

The Code

Here's the code, embedded using codebender!

Try downloading the codebender plugin and clicking on the Run on Arduino button to program your Arduino board with this sketch. And that's it, you've programmed your Arduino with this sketch.

• ultrasonic.Ranging(CM) will return distance from an object to centimeters
• ultrasonic.Ranging(INC) will return distance from an object to inches
• ultrasonic.Timing() will return the time (ms) where the signal took to return from the object

Press the 'connect' button below to start serial communication.

Well done!

You have successfully completed one more Arduino "How to" tutorial and you learned how to use the HC-SR04 Ultrasonic Sensor with Arduino uno.