# Daikin Chiller (RTU) Emulator

This project is an Arduino-based emulator for a Daikin Chiller unit, communicating over Modbus RTU. It is designed to be a flexible template that can be adapted to simulate different types of chillers by modifying the configuration and state logic.

The emulator operates on a state machine with three core states:
* **Standby**: The chiller is idle but ready.
* **Running**: The chiller is active and operational.
* **Fail**: The chiller has encountered a fault condition.

## Features

* **Modbus RTU Communication**: Emulates a Modbus slave device.
* **State Machine Logic**: Simulates different operational states (Standby, Running, Fail).
* **Dynamic Value Simulation**: Uses "Strategies" (e.g., PID, Ramp) to generate realistic, changing values for Modbus points.
* **Configurable Modbus Map**: The entire Modbus register map is defined in a single, easy-to-modify file (`config.h`).
* **Extensible Design**: The structure allows for the addition of new states and behaviors.

## Hardware Prerequisites

The code is written for an ESP8266/ESP32-style microcontroller with WiFi capabilities and at least one hardware serial port for RS485 communication.

* **Microcontroller**: ESP8266, ESP32, or similar.
* **RS485 Transceiver**: A module like the MAX485 to interface with the Modbus RTU bus.

## Software Dependencies

This project relies on a Modbus library. Ensure you have the correct library installed in your Arduino IDE.

* **Modbus Library**: The code uses a library that provides `ModbusRTU.h` and optionally `ModbusIP_ESP8266.h`.

---

## How to Customize for a New Chiller

To adapt this template for a new chiller, follow these steps.

### 1. Configure Device-Specific Parameters (`config.h`)

Open `CH_Daikin_AWV026B_RTU/config.h`. This is the main file for device-specific settings.

#### Modbus RTU Settings
Update the following constants for your device's serial communication setup.
```c++
const int BAUDRATE = 19200;   // The serial communication speed
const int RX_PIN = 17;        // The GPIO pin for receiving data (RX)
const int TX_PIN = 16;        // The GPIO pin for transmitting data (TX)
const int RST_PIN = 4;        // The GPIO pin for RS485 direction control
const int MODBUS_ID = 1;      // The unique slave ID for this device