MicroPython and CircuitPython: Python for Microcontrollers

Table of Contents

  1. Introduction
  2. MicroPython vs CircuitPython
  3. Setting Up MicroPython
  4. Basic MicroPython Commands
  5. MicroPython Libraries
  6. Setting Up CircuitPython
  7. CircuitPython Basics
  8. CircuitPython Libraries
  9. Conclusion

Introduction

Microcontrollers are small computers integrated into various devices and systems to control their behavior. MicroPython and CircuitPython are two stripped-down versions of Python designed to run on microcontrollers, opening up a world of possibilities for programming and automation.

This tutorial aims to introduce you to both MicroPython and CircuitPython, explain their differences, guide you through the setup process, cover basic commands, explore available libraries, and demonstrate how to get started with coding on microcontrollers using Python.

Before starting this tutorial, it is beneficial to have a basic understanding of Python programming and some experience working with electronics and microcontrollers.

MicroPython vs CircuitPython

MicroPython and CircuitPython share the same goal of bringing Python to microcontrollers. However, there are a few distinctions between them. MicroPython is a lean version of Python that targets a wide range of microcontrollers and is generally used in industrial and embedded systems. CircuitPython, on the other hand, is specifically designed to simplify the process of programming microcontrollers for beginners and learners.

The key differences between MicroPython and CircuitPython are in their approach to hardware abstraction, ease of use, and community support. While MicroPython offers more flexibility and support for a wide range of microcontrollers, CircuitPython provides a higher-level interface, making it easier for beginners to get started with hardware programming.

In this tutorial, we will explore both MicroPython and CircuitPython and their respective functionalities.

Setting Up MicroPython

To work with MicroPython, you need to install it on your microcontroller board. The steps for setting up MicroPython may vary depending on the specific board you are using. However, the general process involves the following steps:

  1. Choose a Microcontroller Board: There are several microcontroller boards compatible with MicroPython. The popular ones include ESP32, ESP8266, and Pyboard. Choose the board that suits your requirements.

  2. Download MicroPython: Visit the official MicroPython website (https://micropython.org/) and download the firmware for your microcontroller board. Make sure to download the stable release for your specific board model.

  3. Flash MicroPython Firmware: Connect your microcontroller board to your computer using a USB cable. Open a terminal or command prompt, navigate to the firmware download directory, and execute the command to flash the firmware onto the board. The exact command may differ depending on the board and operating system. Refer to the documentation provided with your board for specific instructions.

  4. Connect to the Microcontroller: Once the firmware is flashed, your microcontroller will restart and enter MicroPython mode. You can establish a serial connection to the microcontroller using a terminal program such as PuTTY or the built-in serial monitor in a Python Integrated Development Environment (IDE).

  5. Verify the Setup: Enter a MicroPython command to verify that the installation was successful. For example, try print("Hello, MicroPython!") and check if the output shows up in the terminal.

Basic MicroPython Commands

Now that you have MicroPython set up on your microcontroller board, let’s explore some basic commands to interact with the board.

  1. Printing: Use the print() function to display messages or variables on the console. For example, print("Hello, MicroPython!") will print the message “Hello, MicroPython!”.

  2. Variables: MicroPython supports variables just like regular Python. You can assign values to variables using the = operator. For example, x = 5 assigns the value 5 to the variable x.

  3. Loops and Conditional Statements: Use loop and conditional statements to control the flow of your program. For example, the while loop allows you to execute a block of code repeatedly until a condition is met.

  4. Input and Output: You can interact with external devices using MicroPython, including sensors, LEDs, and other peripherals. To interface with these devices, you need to understand the specific functions and libraries provided by your microcontroller.

  5. File Operations: MicroPython supports file operations to read from and write to external storage devices like SD cards. Familiarize yourself with the file I/O functions available for your microcontroller.

It’s important to note that the available commands and functions may vary depending on the microcontroller board you are using. Refer to the documentation of your specific microcontroller to learn more about the available features and functionality.

MicroPython Libraries

MicroPython provides a set of built-in libraries to simplify interacting with peripherals and sensors. These libraries provide high-level functions and classes to handle common tasks. Here are a few commonly used libraries:

  1. machine: This library provides functions for interacting with microcontroller-specific hardware peripherals, such as GPIO pins, I2C, SPI, UART, and PWM.

  2. time: The time library allows you to work with time-related functions, such as measuring elapsed time, creating delays, or setting timeouts.

  3. network: The network library provides functions to work with networking protocols, such as Wi-Fi and sockets, enabling your microcontroller to send and receive data over a network.

  4. ujson: This library implements a subset of the JSON specification, allowing you to encode and decode JSON data.

To use a library, you need to import it into your MicroPython code using the import statement. For example, import machine allows you to access the functions and classes provided by the machine library.

Setting Up CircuitPython

Setting up CircuitPython is similar to setting up MicroPython, with a few variations depending on the specific board used. Here is a general outline of the setup process:

  1. Choose a CircuitPython-compatible Board: CircuitPython supports a wide range of microcontroller boards. Choose a board that suits your requirements and has CircuitPython support.

  2. Download CircuitPython Firmware: Visit the official CircuitPython website (https://circuitpython.org/) and download the firmware for your board. Ensure you download the stable release for your specific board model.

  3. Flash CircuitPython Firmware: Connect your microcontroller board to your computer and follow the instructions provided by the board manufacturer to flash the CircuitPython firmware. This typically involves copying the firmware file onto a specific drive or using a flashing tool provided by the manufacturer.

  4. Connect to the Microcontroller: After flashing the firmware, the board will restart in CircuitPython mode. Use a terminal program or Python IDE’s serial monitor to establish a connection with the microcontroller.

  5. Verify the Setup: Enter a CircuitPython command, such as print("Hello, CircuitPython!"), to verify that the installation was successful.

CircuitPython Basics

CircuitPython simplifies hardware programming by providing high-level abstractions and libraries. Let’s explore some basic concepts and commands commonly used in CircuitPython.

  1. Pin Control: CircuitPython provides abstractions to work with GPIO pins, making it easy to read from sensors and control external devices like LEDs. Use the board and digitalio libraries to control pins and set their modes (input/output).

  2. Analog Input: Many microcontroller boards support analog sensors, such as potentiometers or light-dependent resistors (LDRs). Use the analogio library in CircuitPython to read analog values from these sensors.

  3. Pulse-Width Modulation (PWM): PWM is a technique to control the intensity of analog output. Use CircuitPython’s pulseio library to generate PWM signals and control devices like servo motors or LED brightness.

  4. I2C and SPI Communication: CircuitPython simplifies communication with I2C and SPI devices using the adafruit_bus_device library. Learn how to use this library to communicate with devices like accelerometers, displays, or temperature sensors.

CircuitPython Libraries

Similar to MicroPython, CircuitPython provides a rich collection of libraries to interact with various hardware peripherals. Here are a few commonly used CircuitPython libraries:

  1. adafruit_neopixel: This library allows you to work with addressable RGB LEDs, commonly known as NeoPixels. You can control the color, brightness, and animation effects of these LEDs.

  2. adafruit_sensor: Use this library to interface with various sensors like temperature, humidity, or motion sensors. It provides standardized sensor interfaces and simplifies sensor integration.

  3. adafruit_display_text and adafruit_displayio: These libraries enable you to work with displays, including OLED and LCD screens. You can display text, graphics, and images on these screens.

  4. adafruit_motor: The adafruit_motor library provides classes for controlling motors, including stepper motors, DC motors, and servo motors. Use this library to control robot movements or automate mechanical systems.

To use a CircuitPython library, follow the same import syntax as in MicroPython. For example, import adafruit_neopixel will allow you to work with NeoPixels using the functions and classes provided by the adafruit_neopixel library.

Conclusion

MicroPython and CircuitPython are powerful tools for programming microcontrollers using the Python programming language. In this tutorial, we discussed the differences between MicroPython and CircuitPython, walked through the setup process for both, explored basic commands and libraries available in each version, and provided an overview of their capabilities.

With MicroPython and CircuitPython, you can create a wide range of projects, from simple LED control to complex robotics and automation systems. The flexibility, simplicity, and Pythonic nature of both versions make them suitable for beginners and experienced developers alike.

Experiment with different microcontroller boards, libraries, and sensors to unlock the full potential of Python in the world of microcontrollers. Happy coding!

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