KBUS MQTT Bridge

A bridge application that connects WAGO PFC200's K-Bus I/O modules with MQTT for industrial and smart home automation systems. This enables bidirectional communication between PLC digital I/O and MQTT brokers, facilitating IoT integration for both industrial control systems and smart building automation.

Features

• Bidirectional communication between WAGO PFC K-Bus I/O and MQTT
• Configurable mapping between K-Bus I/O points and MQTT topics
• Industrial IoT and smart home integration
• Support for digital I/O, sensors, and actuators
• Heartbeat messages for monitoring
• Support for WAGO PFC200 controllers

Requirements

• WAGO PFC200 controller with firmware supporting K-Bus operations
• WAGO PFC Firmware SDK for cross-compilation
• Rust toolchain 1.85.0 or newer
• ARM GCC toolchain for cross-compilation

Installation

Cross-Compilation Setup

1. Set up the development environment:

# Clone the repository
git clone https://github.com/ldanko/kbus_mqtt_bridge.git
cd kbus_mqtt_bridge

# Set up the development environment
export PTXPROJ_PATH=/path/to/wago/pfc-firmware-sdk-G2/ptxproj

2. Configure the ARM GCC toolchain by creating .cargo/config.toml

[target.armv7-unknown-linux-gnueabihf]
linker = "/path/to/arm-linux-gnueabihf-gcc"

[extra-link-arg]
sysroot="/path/to/ptxproj/platform-wago-pfcXXX/sysroot-target"

3. Build the application:

cargo build --target=armv7-unknown-linux-gnueabihf --release

Configuration

The application can be configured using:

1. Environment variables (highest priority)
2. Config file from command line argument
3. Config file from environment variable
4. Default values (lowest priority)

Configuration File

The application uses a TOML configuration file. By default, it looks for:

• File path specified as a command-line argument
• File path specified in the KBUS_BRIDGE_CONFIG_FILE environment variable

config.toml Example

# Device name used in MQTT topics
device_name = "pfc200_controller"

# MQTT broker connection settings
[mqtt]
broker_host = "mqtt.example.com"
broker_port = 1883
keepalive = "300s"  # Human-readable duration format
heartbeat_interval = "60s"  # Human-readable duration format

Environment Variables

You can override any configuration value using environment variables:

Configuration Validation

The application validates all configuration values:

• Device name: Must not be empty and cannot contain whitespace or MQTT special characters (/, +, #)
• MQTT broker host: Cannot be empty
• MQTT broker port: Cannot be 0
• Keepalive: Must be between 5 seconds and 24 hours
• Heartbeat interval: Must be 0 (disabled) or between 1 second and 1 hour

Use Case Examples

Industrial Applications

• Connect factory floor PLCs to cloud-based monitoring systems
• Enable real-time production data collection via MQTT
• Interface legacy industrial equipment with modern IoT platforms
• Implement predictive maintenance using sensor data
• Monitor remote industrial sites through secure MQTT connections

Smart Home Applications

• Connect physical wall switches to control smart lights
• Bridge heating system controls with Home Assistant or other platforms
• Automate blinds and shades based on time or temperature
• Integrate legacy electrical systems with modern IoT platforms
• Provide reliable, hardware-based automation with MQTT flexibility

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

• WAGO PFC Firmware SDK
• WAGO PFC HowTos