dbus-mqtt-grid - Emulates a physical Grid/Genset/AC Load Meter from MQTT data

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

Index

1. Disclaimer
2. Supporting/Sponsoring this project
3. Purpose
4. Config
5. JSON structure
6. Tasmota
7. Home Assistant
8. Install / Update
9. Uninstall
10. Restart
11. Debugging
12. Compatibility
13. Screenshots

Disclaimer

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

Supporting/Sponsoring this project

You like the project and you want to support me?

Purpose

The script emulates a physical Grid/Genset/AC Load 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, com.victronenergy.genset.mqtt_genset or com.victronenergy.acload.mqtt_acload 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)

Home Assistant

This is only a simple example that can be reduced expanded to match the minimum or full requirements shown above.

alias: mqtt publish sensor grid power
description: ""
trigger:
  - platform: state
    entity_id: sensor.YOUR_GRID_POWER_ENTITY
condition: []
action:
  - service: mqtt.publish
    data_template:
      payload: |
        {
          "grid": {
            "power": {{ (states('sensor.YOUR_GRID_POWER_ENTITY') | float(0)) }},
            "L1": {
                "power": {{ (states('sensor.YOUR_GRID_L1_POWER_ENTITY') | float(0)) }}
            },
            "L2": {
                "power": {{ (states('sensor.YOUR_GRID_L2_POWER_ENTITY') | float(0)) }}
            },
            "L3": {
                "power": {{ (states('sensor.YOUR_GRID_L3_POWER_ENTITY') | float(0)) }}
            }
          }
        }
      topic: homeassistant/energy/grid

In the config.ini of dbus-mqtt-grid set the MQTT broker to the Home Assistant hostname/IP and the topic to the same as in your Home Assistant config (like above).

See also this comment.

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.

Install / Update

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

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

   wget -O /tmp/download_dbus-mqtt-grid.sh https://raw.githubusercontent.com/mr-manuel/venus-os_dbus-mqtt-grid/master/download.sh
   
   bash /tmp/download_dbus-mqtt-grid.sh

3. Select the version you want to install.

4. Press enter for a single instance. For multiple instances, enter a number and press enter.

   Example:

   • Pressing enter or entering 1 will install the driver to /data/etc/dbus-mqtt-grid.
   • Entering 2 will install the driver to /data/etc/dbus-mqtt-grid-2.

Extra steps for your first installation

5. Edit the config file to fit your needs. The correct command for your installation is shown after the installation.

   • If you pressed enter or entered 1 during installation:

   nano /data/etc/dbus-mqtt-grid/config.ini

   • If you entered 2 during installation:

   nano /data/etc/dbus-mqtt-grid-2/config.ini

6. Install the driver as a service. The correct command for your installation is shown after the installation.

   • If you pressed enter or entered 1 during installation:

   bash /data/etc/dbus-mqtt-grid/install.sh

   • If you entered 2 during installation:

   bash /data/etc/dbus-mqtt-grid-2/install.sh

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

Uninstall

⚠️ If you have multiple instances, ensure you choose the correct one. For example:

• To uninstall the default instance:

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

• To uninstall the second instance:

  bash /data/etc/dbus-mqtt-grid-2/uninstall.sh

Restart

⚠️ If you have multiple instances, ensure you choose the correct one. For example:

• To restart the default instance:

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

• To restart the second instance:

  bash /data/etc/dbus-mqtt-grid-2/restart.sh

Debugging

⚠️ If you have multiple instances, ensure you choose the correct one.

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.

Compatibility

This software supports the latest three stable versions of Venus OS. It may also work on older versions, but this is not guaranteed.

Screenshots

Power and/or L1

Power, L1 and L2

Power, L1, L2 and L3