MicroPython Giant Calculator

Overview

This is a MicroPython port of the Impression 5 Giant Calculator Arduino project. Where the original used C++ with specialized Arduino libraries and big-integer arithmetic, this version uses native Python features and object-oriented design on modern MicroPython-compatible hardware.

Hardware

• MicroPython board — ESP32 or Raspberry Pi Pico (configurable)
• 261 NeoPixel LEDs — arranged in a 7-segment format to form a 9-digit display
• 20 push buttons — numeric keys (0–9), operators, equals, and clear

The NeoPixel 7-segment approach means the display can show any color per segment — useful for status indications, highlighting input, or adding visual flair beyond what fixed-segment LED modules allow.

Architecture

The codebase is split into modules to separate concerns:

• display.py — NeoPixel segment mapping and digit rendering
• calculator.py — arithmetic state machine (operands, operators, result)
• buttons.py — GPIO input handling
• config.py — pin assignments and display layout parameters (customize here for your hardware)

Testing Without Hardware

A serial console mode lets you test the calculator logic via terminal without any physical buttons or LEDs connected. Input is typed on a keyboard; output is printed as text. Useful for verifying arithmetic behavior before committing to hardware assembly.

Key Difference from Arduino Version

The Arduino version uses a C++ big-integer library (BigNumber) to support arbitrary precision — important for an exhibit where visitors type very long numbers. The MicroPython version relies on Python floats, which limits precision to approximately 15–17 significant digits. This is a known trade-off; Python’s decimal module could be used to restore arbitrary precision if needed.

Installation

Deploy files to the board using ampy or the Thonny IDE. Edit config.py to match your pin assignments before uploading.