# Tempering Machine Avalonia - AI Agent Instructions

## Project Overview
Industrial chocolate tempering machine control application built with Avalonia UI (.NET 8). Controls hardware via Modbus RTU over serial communication for chocolate heating, cooling, and pouring processes.

## Core Architecture

### Thread-Based Loop System
The application runs 5 concurrent background threads from `MainWindow` constructor:
- **MonitorPortsLoop**: Hardware communication & recipe execution (highest priority)
- **ScreenLoop**: Error handling & UI state management 
- **InteractiveUILoop**: Visual feedback (flashing buttons/indicators)
- **TouchLoop**: Touch input handling for screen dimming
- **CheckInternetLoop**: Network connectivity monitoring

### Hardware Communication Stack
```
Recipe Logic → MainWindow → ModBusMaster → Serial Port → Hardware
```
- **ModBusMaster**: Implements Modbus RTU protocol with CRC validation
- **serialThreadLoop**: Async queue-based serial communication with retry logic
- **HoldingRegister**: State object for motor control, temperature setpoints, and outputs

### Data Persistence (CSV-based)
All configuration stored in root CSV files, managed by `DataBase/` classes:
- `Recipe.csv`: Temperature goals, motor settings, pedal timing
- `Machine.csv`: Hardware limits, delays, pre-heating settings  
- `Mapping.csv`: Hardware address mapping (motors, sensors, I/O)
- `Screen.csv`: Display settings, communication parameters
- `Configration.csv`: PID control parameters per heating element

## Recipe System Architecture

### Three-Phase Process
1. **Heating Phase**: Reach target temperature (both mixer tank + chocolate fountain)
2. **Cooling Phase**: Cool to precise temperature or show delay if already at target
3. **Pouring Phase**: Maintain temperature within tight range

### Critical Temperature Logic
- **Heating**: Error only if temperature < (goal - errorLimit)  
- **Cooling**: Error only if temperature > (goal + errorLimit)
- **Pouring**: Error if temperature outside (goal ± errorLimit)

### State Management
Recipe phases use integer states: `-1` (off), `1` (active), `10` (paused)
Timers control phase transitions with automatic goal checking.

## Hardware Mapping System

### Bit-Based Motor Control
Motors controlled via bit manipulation on `holdingRegister.motor`:
```csharp
// Turn on motor
foreach (var bit in motor.BitNumbers)
    holdingRegister.motor |= (ushort)(1 << bit);
```

### Temperature Control
Four temperature setpoints (`setTemp1-4`) mapped to heating elements:
- Tank Bottom/Wall, Pump, Fountain temperatures
- Values in deciselsius (multiply by 10)
- `-10000` = disabled/off

### I/O Mapping
- Input registers: Temperature sensors, pedal, safety switches
- Output registers: Motors, heaters, alarms
- Mapping defined in `Mapping.csv` with address + bit number pairs

## Key Development Patterns

### Async UI Updates
Always use `Dispatcher.UIThread.Post()` for UI updates from background threads:
```csharp
Dispatcher.UIThread.Post(() => {
    footerMsg.Text = "Status message";
});
```

### Serial Communication
Use queue-based system via `serialThreadLoop.EnqueueWrite/Read()` - never write directly to port.

### Error Handling
Errors use enum-based system (`Error.GridCondition`) with automatic display/removal via `ScreenLoop`.

### Temperature Validation
Recipe editing enforces logical constraints:
- Heating: 40-60°C
- Cooling: 20-40°C  
- Pouring: between cooling and heating goals

## Build & Debug

### Development Setup
- Standard .NET 8 Avalonia project
- Build: `dotnet build` or Visual Studio
- Run: `dotnet run` from `DaireApplication/` directory

### Hardware Testing
Serial communication requires actual hardware or simulator. Debug logs in `serialThreadLoop` show Modbus traffic.

### Common Issues
- Serial port permissions on Linux
- Temperature sensor calibration  
- Recipe phase transitions depend on precise timing
- CSV file corruption breaks app initialization

## File Organization Priorities

When modifying:
1. **Recipe logic**: `MainWindow.axaml.cs` (MonitorPortsLoop method)
2. **UI views**: `Views/UserController/` directory
3. **Hardware mapping**: `DataBase/Mapping.cs` + root `Mapping.csv`
4. **Serial communication**: `Loops/serialThreadLoop.cs`
5. **Error handling**: `ViewModels/Error.cs` + `Loops/ScreenLoop.cs`

## Critical Implementation Notes

- Recipe temperature goals are validated on save, not on start
- Motor state changes require serial write to take effect
- Phase transitions happen automatically based on temperature + time
- CSV files auto-migrate missing columns via `DataPathManager.MigrateCsvFiles()`
- Thread safety critical - all hardware state changes go through main monitor loop

Focus on the interplay between recipe logic, hardware communication, and real-time UI updates when making changes.