Tim's blah blah blah

Smarthome data logging with RPi/domoticz/influxdb/grafana

(Updated: )

When we got a smart meter and solar panels I wanted to record this data. Along the way I added more sensors and I’ve extended the software


  1. Record (smart) meter data and graph it (now including: electricity smart meter via USB, PV via bluetooth, heat meter via machine vision, water meter via line sensor, temperature via EvoHome)
  2. Log data in generic, long-lasting format locally (i.e. no externally hosted solution)
  3. Robust
  4. Interactive graphs on smartphone (domoticz, plot.ly, Highcharts, dygraphs)
  5. Customisable graphs (like grafana)
  6. Cheap/low-power solution (i.e. no Intel NUC)
  7. Versatile wrt interfaces (e.g. bluetooth/wifi/GPIO/USB)
  8. Not used to control or actuate. For that I use COTS products that work and don’t crash :p


Data model


I use only SI units for storing meter data so I can combine e.g. heat meter (native unit MJ) with smart meter (native unit Wh) with PV (native unit kWh).

  1. Power: W, J/s
  2. Energy: J
  3. Temperature: deg C
  4. Wind: m/s
  5. Wind direction: deg
  6. Voltage: V
  7. Water: liter
  8. Rain: mm

Database scheme

Influxdb can only combine / add / subtract data from the same measurement. Keep this in mind when designing your scheme.

Generic format: <unit>, type=<quantity>, device=<datasource>, subtype=<device qualifier> value1=X value2=Y value3=Z <timestamp>.

Fully worked out, this looks like:

    Power,type=elec,device=<kaifa/sma/smartplug> energy=X power=Y
    Power,type=heat,device=<landisgyr> energy=X
    Power,type=radiation,device=solar energy=X
    temperature,type=heating,device=livingroom actual=X setpoint=Y
    temperature,type=device,device=sma actual=X
    temperature,type=weather,device=XXweatherloc actual=X
    wind,type=weather,device=XXweatherloc wind=X
    winddirection,type=weather,device= XXweatherloc winddir=X
    voltage,type=elec,device=sma, DC=X AC=Y
    water,type=potable,device=sensus water=X
    rain,type=weather,device=XXweatherloc rain=X

Optionally this could all be in one table (called ‘measurement’ in influxdb parlance)

Polling cadence

Software architecture


Implementation occurred more or less chronologically in this order. I’ve written the text including hindsight to fix initial mistakes:

  1. Installing domoticz on Rpi
  2. Extending domoticz with influxdb/grafana
  3. Connecting sensors to Rpi/domoticz


Before settling on the above solution I’ve considered (and rejected) the following alternative solutions for various reasons:


#Linux #smarthome