77 lines
2.6 KiB
Markdown
77 lines
2.6 KiB
Markdown
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# Design Document: MicroBadge
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## Overview
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**MicroBadge** is an interactive embedded application built for the BBC
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micro:bit v2. It is written in **Rust** using the **Embassy** async embedded
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runtime. The project functions as a **conference name badge** that acts as a
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professional and technical icebreaker at events.
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The application framework includes:
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* A **menu system** for switching between apps.
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* A **name scroller** for displaying your name or custom message.
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* A **Snake game** for fun and interactivity.
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* A **NFC business card** app for sharing contact info. **Still in progress**
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## Goals
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* Provide a custom and memorable name badge experience.
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* Showcase embedded Rust development using async and no-std.
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* Enable fun interactions and sharing via NFC.
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* Serve as a technical portfolio piece for conferences, meetings, and
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interviews.
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## Architecture
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### 1. Core Framework
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* Built on **Embassy** for asynchronous concurrency.
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* Uses hardware abstraction layers (HALs) for GPIO, timers, display, and
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buttons.
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* Implements a lightweight app-switcher system with a menu UI.
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### 2. Applications
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#### Name Scroller
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* Scrolls a name or message across the LED matrix.
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* Configurable for speed and repeat mode.
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* Useful for identifying the wearer at a glance.
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#### Snake Game
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* Classic Snake game rendered on the 5x5 LED display.
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* Uses `Button A` and `Button B` for turning.
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* Includes food spawning, score tracking, and difficulty selection.
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* Uses PWM for different intensity led lights.
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#### NFC Business Card (WIP)
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* Leverages the onboard NFC peripheral.
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* Intends to share vCard/contact data over NFC.
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* Targeted at mobile phones for quick transfer of contact info
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## User Interaction
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* Navigation is handled via micro:bit's `Button A`, `Button B`, and long-press `Start` gesture
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* LED matrix provides visual feedback for game states and menu navigation
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* Apps are selected from a simple menu UI
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* Snake game is tuned to a slower speed (~4Hz) for usability
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## Development Environment
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* Written entirely in **Rust**, `#![no_std]`
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* Uses **Embassy** for async device access and task scheduling
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* Debugging output via `defmt`
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* Built and flashed using `probe-rs` and `cargo-embed`
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## Future Improvements
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* Finalize NFC vCard transmission
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* Add configuration storage via flash memory
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* Create a desktop companion app for editing settings
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* Support BLE for data sync or configuration
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## Summary
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MicroBadge combines a fun hardware platform with modern Rust development.
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It serves not only as a name badge but also as a way to demonstrate embedded
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skills, share contact info, and invite technical discussion at events.
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