# CircuitPython — Python for Microcontrollers and Embedded Devices

> An Adafruit-maintained fork of MicroPython optimized for learning and rapid prototyping on microcontrollers, with a USB drive workflow and 400+ hardware libraries.

## Install

Save in your project root:

# CircuitPython — Python for Microcontrollers and Embedded Devices

## Quick Use
```python
# Flash CircuitPython UF2 onto a supported board (e.g., Raspberry Pi Pico)
# The board mounts as a USB drive named CIRCUITPY
# Edit code.py on the drive:
import board
import digitalio
import time

led = digitalio.DigitalInOut(board.LED)
led.direction = digitalio.Direction.OUTPUT
while True:
    led.value = not led.value
    time.sleep(0.5)
```

## Introduction
CircuitPython is an education-focused implementation of Python 3 for microcontrollers, maintained by Adafruit. It simplifies embedded development by letting you write Python code directly on a USB-mounted drive without installing compilers, IDEs, or flashing tools, making hardware programming accessible to beginners and rapid prototypers.

## What CircuitPython Does
- Runs Python 3 directly on microcontrollers with 256 KB+ RAM and 32-bit processors
- Mounts the board as a USB drive so code files can be edited with any text editor
- Provides 400+ libraries for sensors, displays, motors, LEDs, and communication protocols
- Includes a serial REPL console for interactive debugging over USB
- Supports 500+ boards from Adafruit, Raspberry Pi, SparkFun, Seeed Studio, and others

## Architecture Overview
CircuitPython is a fork of MicroPython with modifications for USB workflow, API consistency, and beginner friendliness. It runs a bytecode interpreter on the microcontroller that reads `code.py` from the filesystem on each reset. The USB stack provides both a mass storage device (for code editing) and a CDC serial port (for REPL). Hardware abstraction layers map board-specific pins and peripherals to a consistent Python API across different chip families including RP2040, ESP32-S3, nRF52840, and SAMD51.

## Self-Hosting & Configuration
- Download the correct UF2 firmware for your board from circuitpython.org
- Enter bootloader mode (usually double-tap reset) and drag the UF2 file to the boot drive
- Place Python code in `code.py` on the CIRCUITPY drive; it runs automatically on save
- Install libraries by copying `.mpy` files from the Adafruit CircuitPython Bundle to the `lib/` folder
- Use `circup` CLI tool to manage library installation and updates: `pip install circup && circup install adafruit_neopixel`

## Key Features
- No toolchain required: edit code with any text editor, save to USB drive, and it runs
- Built-in USB HID, MIDI, and serial support for custom input devices and instruments
- Wi-Fi and Bluetooth support on ESP32 and nRF boards for IoT applications
- `displayio` library for driving OLED, TFT, and e-ink displays with graphics and text
- Active community with weekly releases and broad board support

## Comparison with Similar Tools
- **MicroPython** — More portable and lower-level; CircuitPython prioritizes beginner experience and USB workflow
- **Arduino (C/C++)** — Faster execution and more memory-efficient; CircuitPython trades performance for ease of use
- **PlatformIO** — Professional embedded toolchain; CircuitPython needs no build tools at all
- **Raspberry Pi OS** — Full Linux on Pi hardware; CircuitPython runs on bare-metal microcontrollers
- **Espressif IDF** — Low-level ESP32 SDK; CircuitPython abstracts hardware for rapid prototyping

## FAQ
**Q: What boards are supported?**
A: Over 500 boards including Raspberry Pi Pico, Adafruit Feather, ESP32-S3 boards, and many others. See circuitpython.org/downloads for the full list.

**Q: Is CircuitPython fast enough for real projects?**
A: For sensor reading, display driving, and IoT tasks it works well. For timing-critical applications like audio DSP or high-frequency PWM, C/C++ may be more appropriate.

**Q: How is it different from MicroPython?**
A: CircuitPython focuses on USB drive workflow, API consistency across boards, and beginner documentation. MicroPython supports more chips and offers lower-level access.

**Q: Can I use regular Python packages?**
A: No. CircuitPython uses its own library ecosystem optimized for microcontrollers. Standard CPython packages are too large for embedded use.

## Sources
- https://github.com/adafruit/circuitpython
- https://circuitpython.org/

---
Source: https://tokrepo.com/en/workflows/asset-abc27e9a
Author: AI Open Source