You can bring a Belgian smart meter’s P1 data into Home Assistant with an ESP32 running ESPHome, provided you use a compatible P1 interface and configure the reader for your meter’s protocol. Home Assistant supports the Belgian V5 variant as DSMR version 5B. The four-hour title is a project target, not a verified or guaranteed completion time: setup depends on the meter, port access, hardware and network configuration.
What you need to check before choosing parts
Belgian P1 is a useful route to energy data, but it does not mean every meter has the same settings or activation rules. Start by identifying the distribution system operator (DSO), meter make and model, and the P1/DSMR version. Fluvius’s e-MUCS P1 V1.7.1 specification lists implementations across DSOs and meter types and notes that not every installed meter can be upgraded to the latest version.
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Also establish whether the P1 port is available on your installation. Sibelga says ports are enabled by default in Brussels; that is not a nationwide rule. Check with the relevant DSO or meter documentation if your reader receives no data.
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| Option | Hardware and setup | Home Assistant path | Trade-off |
|---|---|---|---|
| DIY ESP32 with ESPHome | ESP32 development board and a P1 interface compatible with the meter; configure UART and DSMR. | Use the ESPHome configuration and intended Home Assistant data path for the chosen firmware setup. | Highly configurable, but wiring, UART settings and meter compatibility need attention. |
| USB serial P1 reader | Meter-compatible P1-to-USB serial reader connected to the Home Assistant host. | Configure the DSMR Smart Meter integration to read the serial device. | Avoids ESP32 firmware setup but requires USB access and correct serial-device permissions. |
| Network serial bridge | P1 serial interface connected through a network bridge or proxy. | Configure the DSMR integration to connect through the serial-to-network proxy. | Lets the reader sit near the meter, while adding proxy and network configuration. |
| SlimmeLezer+ | Ready-made ESPHome-powered P1 reader. | Home Assistant describes it as integrating with Home Assistant. | Reduces assembly work; verify current availability and terms separately. |
This guide follows the ESP32 route. A bare ESP32 is not a universal P1 cable: use an interface designed for the meter and board, and follow that device’s wiring instructions. ESPHome’s UART example shows how to configure a receive pin; it does not certify one circuit for every meter.
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Build and configure the ESP32 reader
1. Confirm the electrical interface
Choose a P1-to-UART interface explicitly compatible with your meter and ESP32 board. Confirm its wiring, voltage requirements and pin assignment from the interface documentation before connecting it. Do not connect P1 conductors directly to an ESP32 GPIO based only on a generic diagram.
2. Set up UART and the DSMR component
In ESPHome, configure the UART receive pin and DSMR component for the specific meter. The ESPHome DSMR component documentation gives GPIO16 as an example receive pin and uses 115200 baud in its example. It also notes that some older meters use 9600 baud. These are not interchangeable defaults: check the meter’s version and documentation for baud rate and serial framing.
Rank #2
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- Flexible Power-Saving Modes: ESP32 power-management features support dynamic clock scaling and low-power operating modes, helping developers reduce energy use in compatible sensing, monitoring and connected-device applications, suitable for battery-powered Internet of Things (IoT) devices.
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- Over-the-Air Update Support: Configure OTA functionality through a compatible ESP-32 software framework to update deployed firmware over Wi-Fi without reconnecting the board by USB for every revision
DSMR reception is passive: the meter sends telegrams, and the component decodes them. Do not assume that a listed pin or example configuration will work unchanged with your board and interface.
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3. Check for complete telegrams
Before relying on sensor entities, confirm that the ESP32 receives complete telegrams and that the parsed readings are plausible. If entities remain empty, use ESPHome’s raw telegram logging or bridging and troubleshooting guidance to distinguish a serial-settings problem from an interface, wiring or port-access issue.
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Add the data to Home Assistant
For the Home Assistant DSMR Smart Meter integration, open Settings → Devices & services and add the integration. Choose the connection method that matches your setup: serial data available to the Home Assistant host, or a configured serial-to-network proxy. For a Belgian V5 meter, select DSMR version 5B as specified in the Home Assistant DSMR Smart Meter documentation. Do not select the Dutch DSMR option just because both systems use a P1 port.
After setup, inspect the generated entities and their units before using them in the Energy dashboard. Select cumulative import/consumption and, where available, export/return readings according to their direction. Confirm the values increase in the expected direction; a wrong entity or unit can make dashboard totals misleading. Home Assistant’s electricity grid guidance explains the available Energy integration approaches and the role of a P1 reader.
Rank #4
- 2.4GHz Dual Mode WiFi + Bluetooth Development Board
- Support LWIP protocol, Freertos;ESP32 is a safe, reliable, and scalable to a variety of applications
- SupportThree Modes: AP, STA, and AP+STA
- Ultra-Low power consumption, Compatible with Arduino IDE
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Refresh timing and privacy depend on the installation
Telegram cadence varies with generation and device. Home Assistant describes 10-second telegrams generally and one-second intervals for DSMR 5.0 devices. Sibelga says its Brussels P1 port sends electricity data once a second. Those descriptions do not guarantee that every entity updates at exactly that interval on every installation.
Sibelga describes the meter’s P1 communication as local. Once a reader connects to Wi-Fi or another network, however, the data path depends on how that ESP32 and Home Assistant are configured. Check whether the reader sends data only to your local Home Assistant instance or uses any onward service; the local nature of the meter port alone does not establish the privacy behavior of the whole system.
Quick Recap
Best Value
- 2.4GHz Dual Mode WiFi + Bluetooth Development Board
- Ultra-Low power consumption, works perfectly with the Arduino IDE
- Support LWIP protocol, Freertos
- SupportThree Modes: AP, STA, and AP+STA
- ESP32 is a safe, reliable, and scalable to a variety of applications
When readings do not appear
- No telegrams arrive: Check that the port is enabled for your installation, the interface is compatible, and the wiring follows its instructions.
- Data is incomplete or undecodable: Verify baud rate, receive pin and serial framing against the meter version; use ESPHome raw logging to inspect incoming telegrams.
- ESPHome sees data but Home Assistant does not: Check the selected Home Assistant connection route, such as the serial device or network proxy, and confirm the DSMR integration version selection.
- Energy totals look wrong: Recheck the selected cumulative sensors, units and import/export direction before relying on the dashboard.
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