dbus-mqtt-grid - Emulates a physical Grid Meter from MQTT data

GitHub repository: mr-manuel/venus-os_dbus-mqtt-grid

Disclaimer

I wrote this script for myself. I'm not responsible, if you damage something using my script.

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Purpose

The script emulates a physical Grid Meter in Venus OS. It gets the MQTT data from a subscribed topic and publishes the information on the dbus as the service com.victronenergy.grid.mqtt_grid with the VRM instance 31.

It also supports the Tasmota-SmartMeter format.

Config

Copy or rename the config.sample.ini to config.ini in the dbus-mqtt-grid folder and change it as you need it.

JSON structure

Minimum required

{
    "grid": {
        "power": 0.0
    }
}

Minimum required with L1

{
    "grid": {
        "power": 0.0,
        "L1": {
            "power": 0.0
        }
    }
}

Minimum required with L1, L2

{
    "grid": {
        "power": 0.0,
        "L1": {
            "power": 0.0
        },
        "L2": {
            "power": 0.0
        }
    }
}

Minimum required with L1, L2, L3

{
    "grid": {
        "power": 0.0,
        "L1": {
            "power": 0.0
        },
        "L2": {
            "power": 0.0
        },
        "L3": {
            "power": 0.0
        }
    }
}

Full

{
    "grid": {
        "power": 0.0,
        "voltage": 0.0,
        "current": 0.0,
        "energy_forward": 0.0,
        "energy_reverse": 0.0,
        "L1": {
            "power": 0.0,
            "voltage": 0.0,
            "current": 0.0,
            "frequency": 0.0000,
            "energy_forward": 0.0,
            "energy_reverse": 0.0,
        },
        "L2": {
            "power": 0.0,
            "voltage": 0.0,
            "current": 0.0,
            "frequency": 0.0000,
            "energy_forward": 0.0,
            "energy_reverse": 0.0,
        },
        "L3": {
            "power": 0.0,
            "voltage": 0.0,
            "current": 0.0,
            "frequency": 0.0000,
            "energy_forward": 0.0,
            "energy_reverse": 0.0,
        }
    }
}

Alternatively you can use the json structure produced by Tasmota-EnergyMeter (see section tasmota)

Tasmota

Setting up tasmota as Tasmota-SmartMeter is not part of this documentation. See https://tasmota.github.io/docs/Smart-Meter-Interface/#meter-metrics or https://homeitems.de/smartmeter-mit-tasmota-auslesen/# (German) for detailed information on how to set up Tasmota-EnergyMeter.

In order to get dbus-mqtt-grid working with the Tasmota-SmartMeter, the script on tasmota has to be configured in a specific way.

Depending on your individual Smart Meter, the first part of the script looks like this:

>D
>B
=>sensor53 r
>M 1
+1,3,s,0,9600,grid

Important for dbus-mqtt-grid is, that the <jsonPrefix> of the meter definition is called grid.

Following is an example of the meter metrics:

1,77070100100700ff@1,Current Consumption,W,power,16
1,77070100240700ff@1,Current Consumption P1,W,power_L1,16
1,77070100380700ff@1,Current Consumption P2,W,power_L2,16
1,770701004c0700ff@1,Current Consumption P3,W,power_L3,16

Important are the 2 last parts of each line.

• The last number (16) lets tasmota transmit this reading via mqtt immediately. This is necessary to get updates of the current power consumption as fast as possible.
• The second last entry needs to be named exactly like this: L1: power_L1, L2: power_L2, L3: power_L3, total grid power: power. These are the keywords that are expected by dbus-mqtt-grid.

The MQTT messages sent from tasmota should then look like this:

21:57:13.103 RSL: SENSOR = {"Time":"2023-11-22T21:57:13","grid":{"power":413}}
21:57:13.124 RSL: SENSOR = {"Time":"2023-11-22T21:57:13","grid":{"power_L1":94}}

Sending the total energy (kWh consumed and delivered) is also possible. Since those values are not changing much, it is sufficient to transmit them only every TelePeriod seconds.
Again, the important parts are the last two of each line, where 3 in this case means that you will get a precision of 3 digits (see meter metrics/precision).

1,77070100010800ff@1000,Total Consumed,KWh,energy_forward,3
1,77070100020800ff@1000,Total Delivered,KWh,energy_reverse,3

It is possible to directly use the ip address of your venusOS installation as MQTT host in tasmota. For this to work, set the MQTT part of config.ini to localhost and enable the MQTT server on your venusOS: https://github.com/victronenergy/dbus-mqtt#set-up

The topic in tasmota has to fit together with the config.ini. For example:

Tasmota Topic: SML
Tasmota Full Topic: %topic%/
config.ini topic = SML/SENSOR

Additional information can be found in this issue.

Home Assistant

See this comment.

Install

1. Login to your Venus OS device via SSH. See Venus OS:Root Access for more details.

2. Execute this commands to download and extract the files:

   # change to temp folder
   cd /tmp
   
   # download driver
   wget -O /tmp/venus-os_dbus-mqtt-grid.zip https://github.com/mr-manuel/venus-os_dbus-mqtt-grid/archive/refs/heads/master.zip
   
   # If updating: cleanup old folder
   rm -rf /tmp/venus-os_dbus-mqtt-grid-master
   
   # unzip folder
   unzip venus-os_dbus-mqtt-grid.zip
   
   # If updating: backup existing config file
   mv /data/etc/dbus-mqtt-grid/config.ini /data/etc/dbus-mqtt-grid_config.ini
   
   # If updating: cleanup existing driver
   rm -rf /data/etc/dbus-mqtt-grid
   
   # copy files
   cp -R /tmp/venus-os_dbus-mqtt-grid-master/dbus-mqtt-grid/ /data/etc/
   
   # If updating: restore existing config file
   mv /data/etc/dbus-mqtt-grid_config.ini /data/etc/dbus-mqtt-grid/config.ini

3. Copy the sample config file, if you are installing the driver for the first time and edit it to your needs.

   # copy default config file
   cp /data/etc/dbus-mqtt-grid/config.sample.ini /data/etc/dbus-mqtt-grid/config.ini
   
   # edit the config file with nano
   nano /data/etc/dbus-mqtt-grid/config.ini

4. Run bash /data/etc/dbus-mqtt-grid/install.sh to install the driver as service.

   The daemon-tools should start this service automatically within seconds.

Uninstall

Run /data/etc/dbus-mqtt-grid/uninstall.sh

Restart

Run /data/etc/dbus-mqtt-grid/restart.sh

Debugging

The logs can be checked with tail -n 100 -F /data/log/dbus-mqtt-grid/current | tai64nlocal

The service status can be checked with svstat svstat /service/dbus-mqtt-grid

This will output somethink like /service/dbus-mqtt-grid: up (pid 5845) 185 seconds

If the seconds are under 5 then the service crashes and gets restarted all the time. If you do not see anything in the logs you can increase the log level in /data/etc/dbus-mqtt-grid/dbus-mqtt-grid.py by changing level=logging.WARNING to level=logging.INFO or level=logging.DEBUG

If the script stops with the message dbus.exceptions.NameExistsException: Bus name already exists: com.victronenergy.grid.mqtt_grid" it means that the service is still running or another service is using that bus name.

Multiple instances

It's possible to have multiple instances, but it's not automated. Follow these steps to achieve this:

1. Save the new name to a variable driverclone=dbus-mqtt-grid-2

2. Copy current folder cp -r /data/etc/dbus-mqtt-grid/ /data/etc/$driverclone/

3. Rename the main script mv /data/etc/$driverclone/dbus-mqtt-grid.py /data/etc/$driverclone/$driverclone.py

4. Fix the script references for service and log

   sed -i 's:dbus-mqtt-grid:'$driverclone':g' /data/etc/$driverclone/service/run
   sed -i 's:dbus-mqtt-grid:'$driverclone':g' /data/etc/$driverclone/service/log/run
   

5. Change the device_name and increase the device_instance in the config.ini

Now you can install and run the cloned driver. Should you need another instance just increase the number in step 1 and repeat all steps.

Compatibility

It was tested on Venus OS Large v2.92 on the following devices:

• RaspberryPi 4b
• MultiPlus II (GX Version)

Screenshots

Power and/or L1

Power, L1 and L2

Power, L1, L2 and L3