How Do I Change Data Type in Arduino?


Larry Thompson

Changing the data type in Arduino is an essential skill for any Arduino programmer. Data types allow us to define the type of data we want to store in a variable, such as numbers, characters, or even custom objects. In this tutorial, we will explore how to change the data type in Arduino and understand the different options available.

Understanding Data Types

Before we dive into changing data types, let’s first understand what data types are. In programming, a data type is an attribute of a variable that determines what kind of value it can hold and how the value should be interpreted. Arduino supports several built-in data types, including:

  • int: used to store integer values (whole numbers).
  • float: used to store floating-point numbers (numbers with decimal points).
  • char: used to store single characters.
  • boolean: used to store true or false values.

Changing Data Types

To change a variable’s data type in Arduino, you need to declare it with the desired data type. For example, let’s say we have a variable called myVariable, and we want to change its data type from int to float. Here’s how you would do it:

float myVariable;

In this example, we declared myVariable as a float by using the float keyword followed by the variable name. Now, myVariable can store floating-point numbers.

Casting Data Types

Sometimes, you may need to convert a variable from one data type to another. This process is called casting. Arduino provides two ways to cast a variable:

1. Implicit Casting

Implicit casting happens automatically when you assign a value of one data type to a variable of another compatible data type. For example:

int myInt = 10;
float myFloat = myInt;

In this example, we assigned the value of myInt, which is an integer, to myFloat, which is a float. Arduino automatically converts the integer value to a float.

2. Explicit Casting

If you want to cast a variable explicitly, you can use parentheses and specify the desired data type. Here’s an example:

float myFloat = 3.14;
int myInt = (int)myFloat;

In this case, we explicitly casted myFloat, which is a float, to an integer using the (int) syntax. The resulting value will be truncated (rounded down) since integers cannot store decimal places.


In this tutorial, we learned how to change the data type in Arduino using the appropriate keywords during variable declaration. We also explored implicit and explicit casting for converting variables between data types when necessary. Understanding and utilizing different data types in Arduino will help you effectively handle and manipulate various kinds of data in your projects.

Remember to experiment and practice with different data types to gain a deeper understanding. Happy coding!

Discord Server - Web Server - Private Server - DNS Server - Object-Oriented Programming - Scripting - Data Types - Data Structures

Privacy Policy