ESP-based Wi-Fi eBUS adapter
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-ebus-firmware 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.
- 🔌 Connects to eBUS heating systems (Vaillant and other eBUS-compatible HVAC equipment)
- 📡 Connects the physical eBUS line to a network over Wi-Fi
- 🌍 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
- Bridge (
esp32-c3, default) — transparent bus interface for external software likeebusdon another host. No autonomous participation. - INTERNAL (
esp32-c3-internal) — autonomous participant: polls, commands, MQTT/HA on-device, no external software needed.
Details: wiki 5. Bridge mode and 6. INTERNAL firmware.
- Native MQTT support
- Home Assistant autodiscovery
- Seamless integration into existing automation setups
- Suitable for dashboards, logging, and energy optimization
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.
- ✅ 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