Tadpol’s state of Reality

Home Assistant had added energy monitoring some revisions ago. Which nicely plopped one more ting on my want to do list. Oddly enough, the easiest thing to add was the gas meter.

Some time ago I had purchased a SDR dongle to attempt to intercept the packets for my weather station. After a lot of fighting with that, I found it much easier to just use the wundergroundpws custom componet and pull the data that it uploads to Weather Underground.

We had gotten new gas meters some years ago, and from those fliers, I knew it used radio of some sort. Looking at my gas meter, I saw the ITron branding. A few web searches later, it seemed likely to be using the 915MHz and using something called ERT-SCM. So I tuned the SDR over to 915MHz, and left it be for a few days to see what would turn up. I found the packets I was looking for.

Collector

A raspberry pi with a USB RTL-SDR dongle. Running rtl-433 which despite the name, handles 915MHz just fine.

I have an ansible role setup to install rtl-433, configure it, and install a systemd service to control it. Everything it finds gets pushed into the MQTT broker I have running.

Home Assistant

I have Home Assistant running in Docker on my Synology. Along with the MQTT broker in another docker container.

With the decoded ERT-SCM packets also in MQTT now, I added a manual config to get the sensor into HA.

mqtt:
  sensor:
    - name: "Gas Meter"
      unique_id: gas1234567890
      device_class: gas
      state_topic: rtl_433/node/devices/ERT-SCM/1234567890/consumption_data
      state_class: total_increasing
      unit_of_measurement: CCF
      value_template: "{{ (value | float)/100 }}"

Then over to the Energy dashboard and followed the wizard thingy there to add the gas sensor.