Lin_Simulator/PLAN.md

LIN Master Simulator Tool — Implementation Plan

Context

Build a cross-platform LIN master simulator GUI using BabyLIN devices. Two parallel implementations: Python (PyQt6) and C++ (Qt6). Each step is built, verified, and tested before moving to the next.

Project Structure

LIN_Control_Tool/
├── python/                # Python implementation
│   ├── src/
│   ├── tests/
│   └── requirements.txt
├── cpp/                   # C++ implementation
│   ├── src/
│   ├── tests/
│   └── CMakeLists.txt
└── resources/             # Shared: sample LDF files, icons, etc.

Tech Stack

• Python: PyQt6, ldfparser, pyserial, pytest
• C++: Qt6 (Widgets, SerialPort), CMake, GoogleTest
• LDF parsing (C++): Custom or port of ldfparser logic

Step-by-Step Plan

Step 1 — GUI Skeleton

• Status: DONE — Python (32/32 tests) | C++ (34/34 tests)
• Goal: Main window with all panel placeholders laid out.

Panels:

• Top bar: LDF file loader (path + browse button + auto-reload indicator)
• Left: Connection status panel (device dropdown, connect/disconnect, status LED)
• Center-top: Tx panel (table placeholder — frame name, ID, signals, data, send button)
• Center-bottom: Rx panel (table placeholder — timestamp, frame name, ID, data, signals)
• Bottom: Control bar (start/stop scheduler, manual send)

Python: PyQt6 QMainWindow, QDockWidget or QSplitter layout C++: Qt6 QMainWindow, same layout with .ui or code-based

Testing:

• Launch app, verify all panels render correctly
• Resize window — panels resize proportionally
• Cross-platform: test on macOS, Windows, Linux

---

Step 2 — LDF Loading & Display

• Status: Not started
• Goal: Load an LDF file, parse it, populate Tx/Rx tables with frame/signal info.

Features:

• File picker dialog
• Parse LDF using ldfparser (Python) / custom parser (C++)
• Populate Tx table with master frames (name, ID, length, signals)
• Populate Rx table columns (ready for runtime data)
• Auto-reload: watch file for changes, re-parse on modification
• Error handling for invalid LDF files

Python: ldfparser library, QFileSystemWatcher for auto-reload C++: Custom LDF parser, QFileSystemWatcher

Testing:

• Load valid LDF → tables populate correctly
• Load invalid file → error message shown
• Modify LDF on disk → auto-reload triggers, tables update
• Verify parsed frame IDs, signal names, lengths match LDF content

---

Step 3 — Tx Panel (Signal Editing)

• Status: Not started
• Goal: Editable Tx table where user can modify signal values based on LDF types.

Features:

• Each master frame row expandable to show individual signals
• Signal value editors based on type (bool → checkbox, int → spinbox, enum → dropdown)
• Frame data bytes update live as signals are edited
• Respect signal bit position, length, encoding from LDF
• Manual "Send" button per frame

Python: QTreeWidget or QTableWidget with custom delegates C++: Same with QStyledItemDelegate subclasses

Testing:

• Edit a signal → frame data bytes reflect the change correctly
• Bool signal toggles between 0/1
• Enum signal shows correct value names from LDF
• Integer signal respects min/max range from LDF
• Bit packing: verify multi-signal frames encode correctly

---

Step 4 — Rx Panel (Real-time Display)

• Status: Not started
• Goal: Rx table that shows incoming frames with timestamps.

Features:

• Columns: timestamp, frame name, frame ID, raw data, decoded signals
• Expandable rows to see individual signal values
• Auto-scroll with pause option
• Clear button
• Signal highlighting on value change

Python: QTableWidget with QTimer-based mock data for testing C++: Same approach

Testing:

• Feed mock Rx data → rows appear with correct timestamps
• Auto-scroll follows new data
• Pause stops scrolling, resume catches up
• Signal decode matches expected values
• Performance: handle 1000+ rows without lag

---

Step 5 — Connection Panel & Device Discovery

• Status: Not started
• Goal: Detect BabyLIN devices, show connection status.

Features:

• Scan for available serial ports / BabyLIN devices
• Device dropdown with refresh button
• Connect / Disconnect buttons
• Status indicator (disconnected/connecting/connected/error)
• Display device info on connect (firmware version, etc.)

Python: pyserial for port enumeration, QThread for connection C++: QSerialPort, QSerialPortInfo

Testing:

• No device → dropdown empty, status shows "No device"
• Mock serial port → connection succeeds, status turns green
• Disconnect → status updates, UI re-enables connect
• Unplug during session → error state shown, graceful handling

---

Step 6 — BabyLIN Communication Backend

• Status: Not started
• Goal: Implement the protocol layer for BabyLIN communication.

Features:

• Serial protocol commands (init, send frame, receive frame)
• BabyLIN-DLL/SDK integration if available
• Abstract interface so serial vs SDK can be swapped
• Frame send/receive with proper LIN timing
• Error detection and reporting

Python: pyserial + threading, abstract base class C++: QSerialPort, abstract interface class

Testing:

• Unit test protocol encoding/decoding
• Loopback test if hardware available
• Mock device for CI testing
• Verify frame timing within LIN spec tolerances

---

Step 7 — Master Scheduler

• Status: Not started
• Goal: Periodic frame transmission using LDF schedule tables.

Features:

• Parse schedule tables from LDF
• Run selected schedule with correct timing (slot delays)
• Start/Stop/Pause controls
• Visual indication of currently transmitting frame
• Manual send overrides during schedule execution
• Schedule table selector dropdown

Python: QTimer-based scheduler, QThread for timing accuracy C++: QTimer, dedicated thread

Testing:

• Start schedule → frames sent in correct order and timing
• Stop → transmission halts
• Manual send during schedule → frame injected correctly
• Verify slot timing accuracy (within tolerance)
• Switch schedule tables mid-run

---

Step 8 — Integration & End-to-End

• Status: Not started
• Goal: Wire all components together, full workflow testing.

Features:

• Load LDF → connect device → start schedule → see Rx responses
• Edit Tx signals on-the-fly during active schedule
• Full error handling chain (device disconnect mid-run, etc.)
• Package as standalone executable (PyInstaller / CMake install)

Testing:

• Full workflow with real BabyLIN + LIN slave device
• Stress test: extended run (hours), verify no memory leaks
• Cross-platform packaging and launch test
• Verify all UI states transition correctly

---

Verification Checklist (Every Step)

• Code review — clean, no warnings
• Unit tests pass (pytest / GoogleTest)
• Manual GUI test on at least one platform
• Both Python and C++ versions reach feature parity