ESP32 Engineering Calculator v2

A high-performance, feature-rich engineering calculator built using MicroPython, an ESP32, and an SSD1306 OLED display. It supports everything from basic arithmetic to calculus, matrix operations, and function graphing.

🚀 Features

The calculator is divided into several specialized modes, accessible via a dedicated menu system:

• Standard Calculator: Basic arithmetic with support for trigonometry (sin, cos, tan), logarithms (log, ln), powers, and roots.

• Graphing Mode: Visualizes functions on a Cartesian plane with auto-scaling.

• Calculus Suite: * Numerical Integration: Uses Simpson's/Trapezoidal logic to find the area under a curve.

• Slope (Derivative): Calculates the instantaneous rate of change at a point .

• Algebraic Solvers:

• Equation Solver: Solves Quadratic (exact) and Cubic (Newton-Raphson method) equations.

• System of Equations: Solves linear systems.

• Matrix Operations: Calculate Determinants and Inverses for matrices.

• Base Converter: Convert between Binary, Octal, Decimal, and Hexadecimal.

• Scientific Features: * Shift-key functionality for secondary commands.

• Memory registers (M+, M-, Recall, Clear).

• History scrolling to revisit previous calculations.

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🛠 Hardware Requirements

• Microcontroller: ESP32 (NodeMCU or similar).
• Display: SSD1306 I2C OLED (128x64).
• Keypad: 7x5 Matrix Keypad (Customized layout).
• Firmware: MicroPython (v1.19 or newer recommended).

Pin Mapping (Default)

Component	ESP32 Pin
I2C SCL	GPIO 22
I2C SDA	GPIO 21
Row Pins	33, 25, 26, 27, 14, 12, 13
Col Pins	18, 19, 32, 5, 23

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💻 Installation

1. Prepare the ESP32: Ensure your ESP32 is flashed with the latest MicroPython firmware. You can use Thonny IDE or esptool.py.
2. Install Libraries: You need the ssd1306.py driver. You can install it via Thonny (Tools -> Manage Packages) or download it manually and upload it to your ESP32.
3. Upload the Code:

• Download the main.py from this repository.
• Upload main.py to the root directory of your ESP32.

4. Run: Restart your ESP32. The "RAMAN CALCULATOR v2" splash screen should appear.

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📖 How to Use

• Navigation: Use the UP/DOWN arrows to scroll through the Mode Menu. Press "=" or RIGHT to select a mode.
• Shift Operations: Press the SHIFT key to toggle secondary functions (e.g., changing sin to asin or log to ln).
• Editing: Use the LEFT/RIGHT arrows to move the cursor within an expression. Use "←" for backspace (it is smart enough to delete entire functions like math.sin( at once).
• Exiting Modes: Press the MODE button at any time to escape a sub-mode and return to the selection menu.

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🗃 File Structure

• main.py: The core application containing the display engine, keypad driver, and mathematical logic.
• ssd1306.py: (External dependency) The I2C OLED driver.

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🤝 Contributing

Feel free to fork this project, report bugs, or submit pull requests. I am particularly interested in:

• Implementing System of Equation solvers.
• Optimizing the OLED refresh rate for smoother graphing.
• Adding complex number support to the standard calculator mode.

🔗 Project Links

Resource	Link
GitHub Repository	RMNO21/ESP32-Calculator
Online Simulator	Interactive Wokwi Simulation

Note: The Wokwi simulator is a great way to test the keypad logic and OLED display rendering directly in your browser before assembling the physical hardware.