MicroPython math Module Tutorial with Examples

MicroPython, a lightweight version of Python designed for microcontrollers, includes a subset of Python’s math module.

The math module provides essential mathematical functions and constants that allow you to perform mathematical calculations efficiently on small devices like ESP8266, ESP32, and others.

In this tutorial, we will cover:

Let’s explore each concept with examples.

1. Overview of the MicroPython math Module

The math module in MicroPython provides a collection of functions to perform various mathematical operations. Since MicroPython is designed for constrained environments, the math module is smaller compared to the full Python version. However, it still includes the most commonly used mathematical functions such as trigonometry, logarithmic functions, power functions, and more.

You can import the math module in MicroPython as follows:

import math

2. Mathematical Constants

The math module includes some commonly used mathematical constants such as pi (π) and e.

Example: Mathematical Constants

import math

# Pi constant
print("Pi:", math.pi)  # Output: 3.141592653589793

# Euler's number (e)
print("Euler's number (e):", math.e)  # Output: 2.718281828459045

Output:

Pi: 3.141592653589793
Euler's number (e): 2.718281828459045

• math.pi: Represents the mathematical constant pi (π), approximately 3.14159.
• math.e: Represents Euler’s number (e), approximately 2.71828.

3. Basic Mathematical Functions

The math module provides several basic mathematical functions, such as absolute value, floor, ceil, modf, and more.

Example 1: Absolute Value (fabs())

import math

x = -4.7
print("Absolute value of -4.7:", math.fabs(x))  # Output: 4.7

Example 2: Floor and Ceiling (floor() and ceil())

import math

x = 3.14
print("Floor of 3.14:", math.floor(x))  # Output: 3
print("Ceiling of 3.14:", math.ceil(x))  # Output: 4

Example 3: modf() Function

The modf() function returns the fractional and integer parts of a number as a tuple.

import math

x = 3.14
fractional, integer = math.modf(x)
print("Fractional part:", fractional)  # Output: 0.14
print("Integer part:", integer)        # Output: 3.0

4. Trigonometric Functions

MicroPython’s math module provides several trigonometric functions to perform calculations involving angles.

Example: Trigonometric Functions

import math

# Angle in radians
angle = math.pi / 4  # 45 degrees

# Trigonometric functions
print("sin(45°):", math.sin(angle))  # Output: 0.7071067811865475
print("cos(45°):", math.cos(angle))  # Output: 0.7071067811865476
print("tan(45°):", math.tan(angle))  # Output: 1.0

Output:

sin(45°): 0.7071067811865475
cos(45°): 0.7071067811865476
tan(45°): 1.0

• math.sin(): Returns the sine of an angle (in radians).
• math.cos(): Returns the cosine of an angle (in radians).
• math.tan(): Returns the tangent of an angle (in radians).

Example: Converting Between Degrees and Radians

You can use math.radians() to convert degrees to radians and math.degrees() to convert radians to degrees.

import math

# Convert 90 degrees to radians
radians = math.radians(90)
print("90 degrees in radians:", radians)  # Output: 1.5707963267948966

# Convert pi/2 radians to degrees
degrees = math.degrees(math.pi / 2)
print("Pi/2 radians in degrees:", degrees)  # Output: 90.0

5. Hyperbolic Functions

MicroPython supports hyperbolic functions such as sinh, cosh, and tanh, which are analogous to trigonometric functions but for hyperbolic geometry.

Example: Hyperbolic Functions

import math

x = 1

print("sinh(1):", math.sinh(x))  # Output: 1.1752011936438014
print("cosh(1):", math.cosh(x))  # Output: 1.5430806348152437
print("tanh(1):", math.tanh(x))  # Output: 0.7615941559557649

Output:

sinh(1): 1.1752011936438014
cosh(1): 1.5430806348152437
tanh(1): 0.7615941559557649

• math.sinh(): Returns the hyperbolic sine of x.
• math.cosh(): Returns the hyperbolic cosine of x.
• math.tanh(): Returns the hyperbolic tangent of x.

6. Exponential and Logarithmic Functions

MicroPython’s math module provides functions for exponential calculations and logarithms.

Example 1: Exponentiation (exp())

The exp() function returns e raised to the power of x.

import math

x = 1
print("exp(1):", math.exp(x))  # Output: 2.718281828459045

Example 2: Logarithmic Functions

MicroPython supports natural logarithms (log()) and logarithms with base 10 (log10()).

import math

# Natural logarithm (log base e)
print("log(2):", math.log(2))  # Output: 0.6931471805599453

# Logarithm base 10
print("log10(100):", math.log10(100))  # Output: 2.0

Output:

log(2): 0.6931471805599453
log10(100): 2.0

• math.exp(x): Returns e^x.
• math.log(x): Returns the natural logarithm (log base e) of x.
• math.log10(x): Returns the base-10 logarithm of x.

7. Power and Square Root Functions

The math module provides functions for calculating powers and square roots.

Example 1: Power Function (pow())

The pow() function returns x raised to the power y.

import math

x = 2
y = 3
print(f"{x} raised to the power {y}:", math.pow(x, y))  # Output: 8.0

Example 2: Square Root (sqrt())

The sqrt() function returns the square root of a number.

import math

x = 16
print(f"Square root of {x}:", math.sqrt(x))  # Output: 4.0

Output:

Square root of 16: 4.0

8. Examples and Use Cases

Example 1: Calculating the Hypotenuse of a Triangle

You can use the math.hypot() function to calculate the hypotenuse of a right triangle using the Pythagorean theorem.

import math

# Sides of the triangle
a = 3
b = 4

# Hypotenuse calculation
hypotenuse = math.hypot(a, b)
print(f"Hypotenuse: {hypotenuse}")  # Output: 5.0

Output:

Hypotenuse: 5.0

• math.hypot(a, b): Returns the length of the hypotenuse of a right triangle with sides a and b.

Example 2: Calculating Compound Interest

You can use exponential and logarithmic functions to calculate compound interest.

import math

# Parameters for compound interest calculation
principal = 1000  # Initial investment
rate = 5 / 100  # Annual interest rate

 (5%)
time = 10  # Time in years
n = 12  # Compounded monthly

# Compound interest formula: A = P * (1 + r/n)^(nt)
amount = principal * math.pow((1 + rate / n), n * time)

print(f"Future value after {time} years: {amount:.2f}")

Output:

Future value after 10 years: 1647.01

Summary of MicroPython math Module Functions:

Conclusion

The MicroPython math module provides a variety of essential mathematical functions for performing calculations on microcontrollers.

In this tutorial, we covered:

• Mathematical constants like pi and e.
• Basic mathematical functions such as fabs(), floor(), and ceil().
• Trigonometric and hyperbolic functions.
• Exponential, logarithmic, and power functions.
• Real-world examples like calculating the hypotenuse and compound interest.