esp-arduino-ebus

ESP-based Wi-Fi firmware for eBUS adapter hardware

Warning: Do not power your adapter from a power supply on eBus terminals - you will burn the transmit circuit (receive may still work)!

To get more info navigate to wiki

esp-arduino-ebus is an open-source firmware for EBUS to WiFi Adapter Module.
It turns the adapter into a network-connected eBUS interface with TCP, MQTT, HTTP, and Home Assistant support — suitable for monitoring and controlling eBUS-based heating systems.

⚠️ This firmware is designed to run only on supported eBUS adapter boards.
It is not intended for bare ESP modules without the required eBUS interface circuitry.

---

What This Project Does

• 🔌 Connects to eBUS heating systems (Vaillant and other eBUS-compatible HVAC equipment)
• 📡 Bridges the physical eBUS line to Wi-Fi / Ethernet
• 🌍 Exposes eBUS traffic over TCP sockets compatible with tools like ebusd
• 📊 Publishes data to MQTT for smart home integration
• 🏠 Supports Home Assistant autodiscovery
• ⚙️ Provides a web interface for configuration and diagnostics

---

Required Hardware

This firmware requires a compatible eBUS adapter board, which provides:

• Proper eBUS level shifting and electrical protection
• Safe bus power handling
• Signal conditioning (PWM / comparator circuitry)
• Reliable physical connection to the eBUS line

Supported hardware revisions include multiple ESP32-based eBUS adapter boards maintained alongside this project.

❌ Flashing this firmware onto a generic ESP8266/ESP32 module will not work.

---

🧠 INTERNAL Firmware Mode

In addition to acting as a network bridge, esp-arduino-ebus offers an advanced INTERNAL firmware mode, allowing the adapter to behave as an active, autonomous eBUS participant.

Key INTERNAL Features

• 🧾 Internal command store for eBUS messages
• 💾 Persistent storage in flash, restored after reboot
• 🔍 Automatic eBUS device scanning
• 🔄 Active and passive operation on the bus
• 📡 Full remote control via MQTT or HTTP

INTERNAL Control Capabilities

• Insert or remove stored eBUS commands
• Send single or periodic commands
• Publish stored values on demand
• Enable filtering and forwarding rules
• Trigger bus scans and internal resets

This mode enables standalone operation without requiring external software such as ebusd.

---

Smart Home Integration

• Native MQTT support
• Home Assistant autodiscovery
• Seamless integration into existing automation setups
• Suitable for dashboards, logging, and energy optimization

---

Why Choose esp-arduino-ebus?

• ✅ Designed for real eBUS adapter hardware
• 🔓 Fully open source
• ⚡ Low-power, always-on operation
• 🔧 Flexible: bridge mode or INTERNAL standalone mode
• 🧩 Compatible with existing eBUS tools and ecosystems

---