ESP32-based Wireless M-Bus Gateway with OLED display
wM-Bus Gateway is a compact yet advanced device for receiving data from meters and sensors communicating via the Wireless M-Bus (wM-Bus) standard. The gateway operates in the 868 MHz band and is equipped with an external antenna on an SMA connector, as well as a built-in 2.4 GHz antenna for Wi-Fi and Bluetooth connectivity.
Built on the ESP32 platform, the gateway is designed for full integration with Home Assistant. Thanks to compatibility with ESPHome, the device can be quickly deployed as a home automation component, supporting local frame decoding, data presentation, and wireless communication.
🔧 Key technical features:
- ✅ ESP32 – dual-core microcontroller with Wi-Fi and BLE
- 📡 868 MHz radio receiver with external SMA antenna
- 🌐 Built-in 2.4 GHz antenna for Wi-Fi and Bluetooth
- 🧠 Supports T1 and C1 frames, compatible with the wmbusmeters library
- 🔌 Power: 5 V DC via microUSB
- 📺 1.3″ OLED display – live measurements and status
- 📏 Device dimensions: 70 × 36 × 15 mm
- ⚙️ ESPHome compatibility – full integration with Home Assistant
📡 Bluetooth Proxy for Home Assistant
In addition to its wM-Bus data reception capabilities, the gateway can also function as a Bluetooth Proxy. By enabling the appropriate option in ESPHome, the device can forward data from BLE sensors to Home Assistant, allowing you to read parameters such as temperature, humidity, or motion from distant rooms without the need for additional gateways.
Bluetooth operates in parallel with wM-Bus reception, significantly expanding the device’s functionality without compromising its primary role.
🖥 OLED Display – data always at your fingertips
The built-in 1.3″ OLED display provides quick and convenient access to key information without the need to open an app or log into automation systems. By default, it shows:
- Measurements received from meters (e.g., water, heat, electricity)
- Current device status (Wi-Fi connection, signal strength, reception status)
- Most recent activity and radio transmission parameters
This allows the device to operate completely autonomously – data is available instantly, without relying on external systems or apps.
🛠 Complete openness and flexibility – take control your way
The device works directly with Home Assistant via ESPHome, enabling:
- 🔄 Local frame decoding and exposing data as sensors
- 📤 Publishing data to MQTT, native API, REST endpoints, or TCP/UDP sockets
- 🔧 Easy configuration via YAML or a graphical interface
- 🔄 OTA firmware updates without disassembling the device
Everything operates locally – no intermediaries or cloud required.
The gateway is designed for users who value full control over their hardware. By default, it runs on ESPHome, but you can also:
- 🔄 Upload your own firmware (ESP-IDF, Arduino, MicroPython, etc.)
- 🔌 Integrate the device with other automation systems
- 🌐 Connect the gateway to Supla servers, including as a data source for meters
With open access to the code, documentation, and the well-known ESP32 ecosystem, the gateway can be easily adapted to custom needs and protocols.
Firmware available on: https://github.com/IoTLabs-pl/wM-Bus-Gateway
⚡ Applications:
- Reading water, heat, gas, and electricity meters
- Integration with utility billing systems
- Collecting real-time data for automation and charts
- Local analysis of unusual consumption (e.g., leak detection)
- Extending BLE coverage for Bluetooth sensors throughout the home
💡 Built for complete independence
The Smart wM-Bus Gateway does not require external servers – it operates locally, autonomously, and fully transparently. Thanks to the powerful ESP32 processor, the device can process data on-site, buffer it, and, if needed, forward it to other automation systems. This makes it an ideal solution for users who value reliability, openness, and freedom from vendor lock-in.