Read your Dutch smart meter in Home Assistant via the P1 port
Two ways to get live electricity and gas usage into Home Assistant, and how to choose between a USB cable and a network dongle.
- Published
- Reading time
- 1 min read
- Level
- Beginner
- Tested on HA
- 2026.10
Every Dutch smart meter has a P1 port: an RJ12 socket that reports your current usage every few seconds. Home Assistant turns that into a live energy dashboard.
What you need
- A smart meter with a P1 port (DSMR 4 or 5)
- A P1-to-USB cable, or a P1 dongle that works over Wi-Fi or Ethernet
- Home Assistant on a device near your meter cupboard (USB cable only)
Option 1: USB cable
The cheapest route. Connect the cable to the meter and to the device running Home Assistant, then add the DSMR Slimme Meter integration.
# Example: the serial port is often named like this
/dev/serial/by-id/usb-FTDI_FT232R_USB_UART-if00-port0Option 2: network dongle
If your Home Assistant server is not in the meter cupboard, a dongle that sends the data over your network is more convenient. Many dongles have their own integration or work with the DSMR integration over TCP.
Connect it to the energy dashboard
Go to Settings → Dashboards → Energy and pick the sensors for consumption and return per tariff, plus your gas meter.
Next step
Combine your P1 data with a dynamic energy contract to run appliances when power is cheap. That is the subject of a coming article.