Embedded System Simulator

A C++ simulation framework for embedded systems with clock, timer, I/O, interrupt-like functionality, and a modern Qt-based display interface.

System Simulation Features

• Clock System: Configurable clock with nanosecond simulation time
• Timer Module: Count-up timers with rollover detection and GUI management
• I/O System: Button simulation with FSM-based debouncing
• Interrupt-like CLI: Real-time user input handling via separate thread
• Direct Clock Control: Stop, start, pause, and resume clock via CLI
• Thread-Safe: Atomic operations for thread communication
• Modern Display Interface: Qt-based GUI with interactive controls and terminal
• Interactive Buttons: L1-L4 buttons with custom styling and signal handling
• Integrated Terminal: Built-in CLI terminal within the display window
• Timer Management: Add, start, stop, and remove timers through the GUI

Usage

Running the System

mkdir build && cd build
cmake ..
make
./embedsim

Display Interface

The system now features a modern Qt-based display window (800x500 pixels) with:

• Left Panel: Mini display region (256x256) for future graphics
• Right Panel: Interactive controls and terminal
  • Text Display: Shows system status and messages
  • Control Buttons: L1, L2, L3, L4 (red) and Circle button
  • Timer Management: Add, start, stop, and remove timers
  • Integrated Terminal: Built-in CLI for real-time commands
  • Clock Cycles Display: Real-time clock cycle counter

CLI Commands (Real-time Input)

You can use these commands in both the raw terminal and the integrated display terminal:

Clock Control

• stop - Stop the clock and system (interrupt)
• start - Start the clock (interrupt)
• pause - Pause the clock while maintaining state (interrupt)
• resume - Resume the clock (interrupt)

System Control

• flag - Toggle global interrupt flag
• press <name> - Simulate button press
• release <name> - Simulate button release
• reset <name> - Reset button to IDLE state
• status - Show system status (clock state, cycles, flags, button states)
• close - Close the display window (keeps program running)
• exit - Close the display window and exit the program
• help - Show available commands

Timer Management (GUI + CLI)

• Add timers through the GUI interface
• Start/stop timers via GUI buttons or CLI commands
• Real-time timer status display
• Timer rollover detection and cycle counting

Example Session

Display Terminal

Embedded System CLI Terminal
Type 'help' for available commands
----------------------------------------
CLI> status
=== System Status ===
Clock running: YES
Clock paused: NO
Global flag: OFF
Clock cycles: 0
Button aButton: Input=LOW, State=IDLE
===================

CLI> press aButton
Simulated button press for: aButton

CLI> status
=== System Status ===
Clock running: YES
Clock paused: NO
Global flag: OFF
Clock cycles: 15
Button aButton: Input=HIGH, State=PRESSED
===================

CLI> exit
Exiting program...
Display window closed.
Exit requested. Terminating program...

Raw Terminal (still available)

CLI> status
Clock running: YES
Clock paused: NO
Global flag: OFF
Clock cycles: 0
Button aButton: Input=LOW, State=IDLE

CLI> stop
Interrupt: Stopping clock
System stopped.

Architecture

Modern GUI Architecture

• Qt Integration: Cross-platform GUI framework
• Event-Driven: Button clicks and terminal input handled through Qt signals
• Thread-Safe Communication: GUI and system communicate through callback functions
• Responsive Interface: Real-time updates without blocking system simulation

Clock-Synchronized Operations

• Main polling loop runs synchronized with clock cycles
• I/O polling and timer operations occur on positive clock edges
• Atomic flags allow real-time communication between threads
• GUI updates synchronized with system state

Interrupt-like System

• CLI runs in separate thread for real-time input
• Dual CLI Support: Both raw terminal and integrated display terminal
• Atomic variables provide thread-safe communication
• Interrupt handlers can be registered for custom actions
• Direct clock control through interrupt triggers

Display Integration

• Window Management: 800x500 pixel main window with organized layout
• Button Integration: L1-L4 buttons with custom styling and signal handling
• Terminal Integration: Built-in CLI terminal within the display
• Timer GUI: Visual timer management interface
• Real-time Updates: System status displayed in real-time

Key Components

• System: Main orchestrator with interrupt handling, clock control, and display management
• DisplayApp: Qt-based display interface with integrated terminal and controls
• Clock: Threaded clock with configurable frequency and direct control
• IO: Button simulation with FSM debouncing
• Timer: Count-up timers with rollover detection and GUI management

Display Module Features

Window Layout

• Size: 800x500 pixels (configurable)
• Left Panel: Mini display region (256x256) for future graphics
• Right Panel: Interactive controls and terminal
• Responsive Design: Adapts to different screen sizes

Interactive Elements

• L1-L4 Buttons: Red-styled buttons with custom signal handling
• Circle Button: Interactive button with click detection
• Timer Controls: Add, start, stop, and remove timers
• Terminal Interface: Built-in CLI with command history

Terminal Features

• Command Input: Type commands directly in the display
• Output Display: Real-time command output and system status
• Command History: Previous commands visible in terminal
• Error Handling: Graceful error messages for invalid commands

Timer Management Interface

• Add Timer: Specify name and duration
• Start/Stop: Control individual timers
• Status Display: Real-time timer information
• Remove Timer: Clean up unused timers

Drawing on the Display

Examples

# Draw a red line from (10,10) to (100,100)
line 10 10 100 100 FF0000

# Draw a blue solid rectangle at (50,50) with size 80x60
rect 50 50 80 60 0000FF

# Draw a blue hollow rectangle at (50,50) with size 80x60
rect 50 50 80 60 0000FF hollow

# Draw a green solid circle at (150,150) with radius 40
circle 150 150 40 00FF00

# Draw a green hollow circle at (150,150) with radius 40
circle 150 150 40 00FF00 hollow

# Change object with ID 2 to hollow fill style
fillstyle 2 hollow

# Remove object with ID 2
remove 2

# Show all graphics objects
graphics

# Show memory usage
memory

# Clear all graphics
clear

Fill Style Options:

• Solid (default): Objects are filled with the specified color
• Hollow: Objects have only borders in the specified color, no fill
• Use solid or hollow as the last parameter for rectangles and circles
• Use fillstyle <id> <solid|hollow> to change existing objects

Requirements

• Qt6 (Qt5 fallback supported)
• CMake 3.13 or higher
• C++14 or higher
• Cross-platform: macOS, Windows, Linux

Installation

Installing Qt

macOS:

brew install qt

Ubuntu/Debian:

sudo apt-get install qt6-base-dev
# or for Qt5:
sudo apt-get install qt5-default

Windows: Download Qt from https://www.qt.io/download

Building

mkdir build && cd build
cmake ..
make

Application Icon

The application includes a custom icon that appears in:

• Dock (macOS)
• Taskbar (Windows)
• Window title bar
• System menus

Icon file: icons/app_icon.png (automatically included via Qt resources)

Integration Notes

• Dual CLI Support: Use either the raw terminal or integrated display terminal
• Thread Safety: GUI and system simulation run in separate threads
• Real-time Updates: System status updates in real-time through the GUI
• Clean Exit: Both close and exit commands work properly
• Modern Interface: Professional-looking GUI with intuitive controls

Future Enhancements

• Graphics Rendering: Mini display region for custom graphics
• Custom Themes: Configurable color schemes and styling
• Plugin System: Extensible architecture for additional features
• Network Support: Remote monitoring and control capabilities