Water meter
I also managed to collect consumption data from my water meter.
It’s a Itron Hershey Translator Sensus ECR ERW-0771-412, with FCC ID EO960W on 915 MHz.
I found this by just running rtl_433 -f 915M – this got me the ID for the mqtt topic (which is the same as the one printed on the box).
Aside, I’ve also tried other bands but haven’t found anything interesting yet. My power meter is unfortunately in the 2.4GHz band which the USB RTL-SDR can’t do. YMMV
rtl_433
With the above configuration, the biggest change is to get rtl_433 to listen on both the 433MHz and 915Mhz bands. I added the following to my /etc/rtl_433/service.conf:
# scan 433 and 915, but spend more time in 433
hop_interval 60
frequency 433.92M
frequency 915M
frequency 433.92M
frequency 433.92M
The meter broadcasts about every 45 seconds, so with this config, rtl_433 spends 3 minutes listening on 433MHz for every 1 minute on 915MHz.
Home Assistant Sensors
The sensor in Home Assistant is pretty easy:
- platform: mqtt
name: Water Consumption
unit_of_measurement: 'm³'
value_template: '{{ value_json.consumption_data }}'
state_topic: rtl_433/ERT-SCM/27xxxxxx
json_attributes_topic: rtl_433/ERT-SCM/27xxxxxx
I also added some utility_meter sensors to track consumption over time:
utility_meter:
water_consumption_daily:
source: sensor.water_consumption
cycle: daily
water_consumption_weekly:
source: sensor.water_consumption
cycle: weekly
water_consumption_monthly:
source: sensor.water_consumption
cycle: monthly
Why?
I don’t know. Because it’s there and was easy.
It’s worth noting that because this is in m³ (1 cubic meter == 1000L == 264.17 gallons) with no fractional value the number changes quite slowly. I’m not sure what I’m going to do with this yet other than show a “weekly/monthly water usage” metric on a dashboard.
I will likely not keep the “daily” consumption meter, because we go through less than 1000L per day and so it often shows 0. I’ve only had it increase by 2 since I started monitoring – I got lucky and the first happened literally within an hour of when I first added the sensor.