Multi-app-hub-control

I initially set out to build a simple Pomodoro timer to boost my productivity (with an endless pool of projects to tackle). But after doing some research, I realized it wasn’t exactly groundbreaking, everyone had already built one or better, knob-based devices are especially popular in the maker community.

So, in search of a reason to stand out in this vast sea of incredible projects, I decided not to focus solely on functionality. Instead, I aimed to create a reusable and scalable framework for knob-based device.

If you ever use this to build your own embbeded device, I’d be genuinely thrilled!

• Hardware Abstraction Layer (HAL): Clean interfaces for display, encoder, RGB, buzzer
• Services: High-level abstractions (RGB patterns, tune player, display management)
• Apps: Self-contained applications with standardized lifecycle
• Handlers: Coordinate between hardware events and app logic
• Service Registry: Dependency injection system for shared resources

Architecture & Design Patterns

• SOLID Principles: Interface segregation, dependency injection, single responsibility
• Factory Pattern: Hardware abstraction and initialization
• Observer Pattern: Timer-based update system
• State Machine: Complex UI state management (see PomodoroSettingsFSM)

Embedded Systems Expertise

• Interrupt Handling: Proper ISR implementation with flags
• Real-time Coordination: Timer-based multi-service orchestration
• Hardware Abstraction: Clean separation between hardware and business logic
• Memory Management: Efficient resource usage on constrained hardware

Modern C++ Practices

• RAII: Resource management through constructors/destructors
• Templates & Inheritance: Clean polymorphic interfaces
• Const Correctness: Proper use of const methods and parameters
• Type Safety: Strong typing for display data and configuration

Communication Protocols

• SPI: TFT display communication
• I2C: Sensor integration ready
• Bluetooth Low Energy: HID device implementation
• PWM: RGB LED and buzzer control