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Ultrasonic

Minimalist library for ultrasound module to Arduino

Compatible with HC-SR04, Ping))) and Seeed SEN136B5B (from Seeed Studio)

Work with ultrasonic modules is fairly simple, but can be even more practical if you abstract the control of some features. This library aims to resource efficiency and to simplify access to data.

Where necessary use the ultrasonic module HC-SR04 (one of the most common on the market), Ping))) and/or Seeed SEN136B5B (from Seeed Studio), there are hundreds of libraries that purport to provide the most diverse roles for the user, however, the vast majority of the time, we just need to find out the distance and is that's what does this library.

This library is minimalist, reduces code execution, validation and unnecessary use of global variables, prioritizing smaller data types.

You can run the library examples on the Wokwi Arduino simulator. Wokwi is a free Arduino simulator which runs on the browser. Here are two examples presenting the features of the Ultrasonic library

Example 1 - Ultrasonic distance measurement using 4 pin and 3 pin sensor versions

Example 2 - Reading distance in both centimeters and inches

Wiring:

It is very easy to connect an ultrasound module to the Arduino. For example, if you are using HC-SR04, connect the trigger and echo pin module on pin 12 and 13 of the Arduino, respectively. As in the picture:

If you are using a module with three pins (like Ping))) or Seeed SEN136B5B), you can conect the sig pin module on pin 13 of the Arduino.

You can use the Fritzing(.fzz) files inside extras to draw your prototypes.

How to use:

The idea is to provide a simpler environment possible. To do this, simply follow the steps:

1. Installing

   First you need to import the library so that the IDE recognizes it. The simplest way is importing through the IDE itself:

   • Click in Sketch > Include Library > Manage Libraries...;
   • In the search field type: ultrasonic;
   • In the list, look for Ultrasonic by Erick Simões;
   • Click on Install.

   Alternatively, you can download the library here and import the .zip file into the IDE (see how to import a library here).

2. Importing on code

   To import the library to your code, just write at the beginning of the code #include <Ultrasonic.h> or, in the Arduino IDE, click in Sketch > Include Library > Ultrasonic (will have the same result).

3. Starting (the most exciting part)

   Now is simply create a variable of type Ultrasonic passing as parameters two values representing, respectively, the Trig (emitter) and Echo (receiver) pins. Like this:

   Ultrasonic ultrasonic(12, 13);

   If you are using a module with three pins (like Ping))) or Seeed SEN136B5B), pass as a parameter only the signal pin. Like this:

   Ultrasonic ultrasonic(13);

4. Discovering the distance

   Having initialized a variable, you can run hers from the method that returns the distance read by module Ultrasonic: read():

   ultrasonic.read();

5. Only this?

   Yes. That's it. By default, the value returned from the function read() is the distance in centimeters. See full sample code here.

6. Seriously?

   You can still do a little more determining the unit of measurement that will be returned (centimeters (CM) or inches (INC)).

   ultrasonic.read()    // distance in CM
   ultrasonic.read(CM)  // distance in CM
   ultrasonic.read(INC) // distance in INC

   You can also use more than one ultrasound module:

   Ultrasonic ultrasound1(12, 13);
   Ultrasonic ultrasound2(10, 11);
   Ultrasonic ultrasound3(5);

7. Timeouts

   If there is no object in range, the library will lock-up as it waits for the return pulse. You can change how long to wait by setting a timeout (in microseconds) in the constructor:

   Ultrasonic ultrasonic(12, 13, 40000UL);

   Or during runtime:

   ultrasonic.setTimeout(40000UL);

   The default value is 20000UL (Unsigned Long).

   Using a 40ms timeout should give you a maximum range of approximately 6.8m. You may need to adjust this parameter.

See the examples here.

License

Ultrasonic by Erick Simões is licensed under a MIT License. Based on the work of Carl John Nobile available here. Feel free to contact the author on Twitter: @AloErickSimoes

See LICENSE for details.