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You would think "numbers would be numbers" in all languages but it truly isn't quite the case. All numbers are internally represented in binary inside the microcontroller/computer but how the programming language provides number support tends to vary from language to language.

Types of Numbers

  • Integers
  • Floating Point Numbers
  • Boolean (true/false)

Often times, you need to know the precision - how big or small the number might be to select the best way to use it in a computer program. This makes using numbers a bit trickier but it is fairly easy to learn.


In Arduino, you have the following types of variables:

  • int for an integer, a value without a decimal point. typical ranges for an integer are -32,768 to zero to 32,767. Examples are 279, 1001, 0, -23, -990.
  • long is a large integer and can be a value from -2,147,483,648 to 2,147,483,647.
  • float for floating point numbers (numbers with a decimal point and fractional amount). Examples are 3.1415, -22.2, 0.0, 430000.01. Numbers can be as large as 3 x 10 to the 38th power
  • char for a single character. For example, reading serial data may involve a receive function providing a character value when data is received. A character may basically be any symbol on the keyboard (0 to 255).

The types.h library provides a more modern representation of numbers that tend to behave the same on different devices.

An unsigned short integer, uint8_t, is often used by functions, it also ranges from 0 to 255.

Boolean math is generally done with int values. 0 is false and anything that is not zero, such as 1, is true.

Python / CircuitPython

CircuitPython tries to follow the standard Python implementation (often called CPython) as close as possible. Given microcontrollers do not have an operating system, some things are done a bit differently, but these are documented.

Here are the current types in CircuitPython:

  • Integers, but not currently long integers
  • Floating-Point Numbers.
  • Strings
  • Boolean

Boolean is an actual type in CircuitPython and can be the values True or False.

Rather than use arrays of characters (null/zero terminated) as Arduino does, CircuitPython has a dedicated Strings type. Note that CircuitPython Strings are NOT null/zero terminated, so use of the length properties is how you work with string length.

Changing the Type of Numbers

In Arduino/C this is called casting. Place the type of the number you want in parenthesis before the variable.

int a;
float b;

b = (float)a;
a = (int)b;

In CircuitPython, you use function-like syntax:

x = 5
y = 3.14

z = float(x)
z = int(y)

Division, One Slash vs. Two

A single forward slash / is floating point division in both languages.

A double slash // in Python is special. It divides and drops any values past the decimal point, often called a floor function.


# Python code for / and // operators
x = 15
y = 4

# Output: x / y = 3.75
print('x / y =', x/y)

# Output: x // y = 3
print('x // y =', x//y)

Logical Operators

Logical operators are used mainly in if statements and other block / loop statements. These are NOT the operators used for bitwise and/or/not, only for constructing logical comparisons.







Arduino / C




Python / CircuitPython




// Arduino / C Logical Operators

a = 5;
b = 7;

if( a > 2 && b < 10) {
# CircuitPython Logical Operators

a = 5
b = 7

if a > 2 and b < 10:

This guide was first published on Oct 22, 2018. It was last updated on Oct 22, 2018.

This page (Working with Numbers) was last updated on Apr 20, 2021.

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