This manual found here covers MQTT and how it can be used to send "D.Bus" commands:
https://github.com/victronenergy/dbus-mqtt/blob/master/README.md
An example write request is given here:
Example: On a Hub-4 system we can change the AC-In setpoint with this message:
Topic: W/e0ff50a097c0/vebus/257/Hub4/L1/AcPowerSetpoint Payload: {"value": -200}
I have identified the D.Bus "paths" I wish to control, here:
The ESS related D-Bus paths are:
com.victronenergy.settings /Settings/CGwacs/AcPowerSetPoint (Grid power setpoint)
com.victronenergy.settings /Settings/CGwacs/MaxChargePercentage (Enable/Disable charger)
com.victronenergy.settings /Settings/CGwacs/MaxDischargePercentage (Enable/Disable inverter)
I have 0 experience with MQTT however, and am not sure how to setup a "client" or "subscribe" to the VenusGX's built in Mosquito "Broker", let alone issue a command as shown in example above. Is anyone able to provide some basic instructions or a link to where I might learn how to do this? Ideally I would like to run the MQTT "client" on an Android platform, although I suspect guides that cover this on a Rasberry Pi can be easily adapted. Any help with this is appreciated, thank you!