🧮 Numworks Application Template (RUST)

A simple yet powerful Rust template for developing applications on Numworks calculators

📋 Overview

This template provides a minimal foundation for creating Rust applications that run natively on Numworks calculators (N110, N115, N120). It includes a "Hello World" example that displays perfectly centered text on the screen.

✨ Features

• 🦀 Rust no_std configuration for embedded calculators
• 🎯 ARM cross-compilation with thumbv7em-none-eabihf
• 🔧 EADK Numworks SDK integration
• 🖥️ Epsilon simulator support
• ⚡ Build system with Just
• 🎨 Working Hello World example with perfect text centering
• 📱 Multi-calculator support (N110, N115, N120)

📦 Prerequisites

To build this application, you need to install:

• 🦀 Rust compiler with embedded ARM support
• 🔨 Arm GCC compiler
• 📦 Node.js
• 🛠️ EADK Numworks SDK via nwlink

⚠️ Important: Make sure arm-none-eabi-gcc is in your PATH.

For detailed SDK installation instructions, follow this guide.

🚀 Installation

# On macOS with Homebrew
brew install rustup node

# Or equivalent on your OS
rustup-init
rustup target add thumbv7em-none-eabihf
cargo install just # Makefile alternative

🎮 Usage

🔨 Build the application

just build

📱 Send to calculator

Connect your calculator and run:

just send

🖥️ Run on simulator

just sim

You can speed up simulator compilation by specifying the number of jobs:

just sim 5

⚠️ Known Issues

🖥️ Simulator Video Error

If you encounter a video error when launching the simulator, use this command to force X11 driver usage:

export SDL_VIDEODRIVER=x11
just sim

This command resolves video compatibility issues on some Linux systems.

📁 Project Structure

📦 num-template/
├── 📁 src/
│   ├── 📄 main.rs          # 🚀 Main entry point
│   ├── 📄 eadk.rs          # 🔧 EADK SDK bindings
│   └── 📁 libs/            # 📚 C libraries (storage)
│       ├── 📄 storage.c
│       └── 📄 storage.h
├── 📁 assets/
│   └── 🖼️ icon.png         # 🎨 Application icon (55x55 PNG)
├── 📄 build.rs             # ⚙️ Custom build script
├── 📄 Cargo.toml           # 🦀 Rust configuration
└── 📄 justfile             # 🔨 Build commands

🛠️ Development

🎨 Customizing the application

Edit src/main.rs to customize your application. The current example displays "Hello World!" with perfectly centered text and waits for the EXE key to exit.

🖼️ Important: Icon Size Configuration

When you replace the default icon with your own, you must update the array size in main.rs:

// Change this size to match your icon's byte size
pub static EADK_APP_ICON: [u8; 1520] = *include_bytes!("../target/icon.nwi");

How to find your icon size:

# Check the size of your generated icon
ls -la target/icon.nwi

If the compilation fails with a "mismatched types" error, it means the array size doesn't match your icon's actual size. Update the number in the brackets [u8; YOUR_SIZE_HERE] to fix this.

➕ Adding features

• 🔧 Use EADK APIs in src/eadk.rs for display, input, etc.
• 📦 Add your dependencies in Cargo.toml
• ⚡ Respect no_std constraints for calculator compatibility

📱 Calculator support

• N110/N115: ✅ Full support
• N120: ✅ Full support with better performance
• Simulator: 🖥️ Development and testing

🔍 Key Features Explained

🎯 Text Centering

The template includes a estimate_text_width() function that calculates text width based on character count and font size, enabling perfect horizontal centering on the 320x240 calculator screen.

🌐 Cross-platform Development

• Calculator: 🎯 ARM Cortex-M target with no_std
• Simulator: 🖥️ Native platform for development and testing
• Build system: ⚡ Automated cross-compilation and deployment

💾 Memory Management

• 🔄 Embedded allocator for heap management
• ⚡ Optimized for calculator memory constraints
• 🛡️ Safe memory operations with overflow protection

🚀 Getting Started

1. 📥 Clone this template
2. 📦 Install prerequisites
3. 🖼️ Add your assets/icon.png (16x16 PNG)
4. ✏️ Modify src/main.rs for your application
5. 🔨 Build with just build
6. 🧪 Test with just sim or deploy with just send

🤝 Contributing

This template is designed to be a starting point for Numworks calculator applications. Feel free to:

• ➕ Add more examples
• ⚡ Improve the build system
• 🛠️ Add utility functions
• 📱 Create application templates for specific use cases

📄 License

This template is provided as-is for educational and development purposes. Please respect Numworks' terms of service when developing applications for their calculators.

📚 Source

This template was inspired by the amazing work done in NumcraftRust - a Minecraft-like game running natively on Numworks calculators. The project demonstrates the incredible potential of Rust for embedded calculator development and serves as an excellent reference for advanced Numworks applications.