A simple service for top balancing LiFePO4 batteries with a Victron MultiPlus-II with a constant current

VirtualBatteryMonitor.py

#!/usr/bin/env python3

"""
A class to put a simple service on the dbus, according to victron standards, with constantly updating
paths. See example usage below. It is used to generate dummy data for other processes that rely on the
dbus. See files in dbus_vebus_to_pvinverter/test and dbus_vrm/test for other usage examples.

To change a value while testing, without stopping your dummy script and changing its initial value, write
to the dummy data via the dbus. See example.

https://github.com/victronenergy/dbus_vebus_to_pvinverter/tree/master/test
"""
from gi.repository import GLib
import platform
import argparse
import logging
import sys
import os
import dbus
import os

# our own packages
sys.path.insert(1, os.path.join(os.path.dirname(__file__), "../ext/velib_python"))
sys.path.insert(1, "/opt/victronenergy/dbus-systemcalc-py/ext/velib_python")
from vedbus import VeDbusService
from vedbus import VeDbusItemImport

class VirtualBatteryMonitor(object):
    def __init__(
        self,
        servicename,
        deviceinstance,
        paths,
        productname="MultiPlus Charger",
        connection="dbus",
    ):

        try:
            # Connect to the sessionbus. Note that on ccgx we use systembus instead.
            logging.debug("Opening SystemBus ...")
            dbusConn = dbus.SystemBus()
            logging.info("Opening SystemBus SUCCEEDED.")
        except:
            logging.error("Reading system SOC FAILED.")

        logging.debug("Opening dbus '%s' ...", servicename)
        self._dbusservice = VeDbusService(servicename)
        logging.info("Opening dbus '%s' SUCCEEDED.", servicename)
        self._paths = paths

        logging.debug("%s /DeviceInstance = %d" % (servicename, deviceinstance))

        # Create the management objects, as specified in the ccgx dbus-api document
        self._dbusservice.add_path("/Mgmt/ProcessName", __file__)
        self._dbusservice.add_path("/Mgmt/ProcessVersion", "Unkown version, and running on Python " + platform.python_version())
        self._dbusservice.add_path("/Mgmt/Connection", connection)

        # Create the mandatory objects
        self._dbusservice.add_path("/DeviceInstance", deviceinstance)
        self._dbusservice.add_path("/ProductId", 0)
        self._dbusservice.add_path("/ProductName", productname)
        self._dbusservice.add_path("/FirmwareVersion", 0)
        self._dbusservice.add_path("/HardwareVersion", 0)
        self._dbusservice.add_path("/Connected", 1)

        # Create all the objects that we want to export to the dbus
        self._dbusservice.add_path('/Dc/0/Voltage', 3.4 * 16, writeable=True)
        self._dbusservice.add_path('/Dc/0/Current', 5, writeable=True)
        self._dbusservice.add_path('/Dc/0/Power', 3.4 * 16 * 2, writeable=True)
        self._dbusservice.add_path('/Dc/0/Temperature', 15, writeable=True)
        self._dbusservice.add_path('/Dc/0/MidVoltage', None)
        self._dbusservice.add_path('/Dc/0/MidVoltageDeviation', None)
        self._dbusservice.add_path('/ConsumedAmphours', 123, writeable=True)
        self._dbusservice.add_path('/Soc', 75, writeable=True)
        self._dbusservice.add_path('/TimeToGo', None)
        self._dbusservice.add_path('/Info/MaxChargeCurrent', 5, writeable=True)
        self._dbusservice.add_path('/Info/MaxDischargeCurrent', 0, writeable=True)
        self._dbusservice.add_path('/Info/MaxChargeVoltage', 3.65 * 16, writeable=True)

        self._dbusservice.add_path('/Info/BatteryLowVoltage', 2.75 * 16, writeable=True)
        self._dbusservice.add_path('/Info/ChargeRequest', False, writeable=True)
        self._dbusservice.add_path('/Alarms/LowVoltage', 0, writeable=True)
        self._dbusservice.add_path('/Alarms/HighVoltage', 0, writeable=True)
        self._dbusservice.add_path('/Alarms/LowSoc', 0, writeable=True)
        self._dbusservice.add_path('/Alarms/HighCurrent', 0, writeable=True)
        self._dbusservice.add_path('/Alarms/LowCellVoltage', 0, writeable=True)
        self._dbusservice.add_path('/Alarms/LowTemperature', 0, writeable=True)
        self._dbusservice.add_path('/Alarms/HighTemperature', 0, writeable=True)

        self._dbusservice.add_path('/Capacity', 156, writeable=True)
        self._dbusservice.add_path('/CustomName', "Virtual Battery Monitor (%/V/W)", writeable=True)
        self._dbusservice.add_path('/InstalledCapacity', 280, writeable=True)

        self._dbusservice.add_path('/System/MaxCellTemperature', 15, writeable=True)
        self._dbusservice.add_path('/System/MaxCellVoltage', 3.4, writeable=True)
        self._dbusservice.add_path('/System/MaxTemperatureCellId', "C5", writeable=True)
        self._dbusservice.add_path('/System/MaxVoltageCellId', "C2", writeable=True)
        self._dbusservice.add_path('/System/MinCellTemperature', 15, writeable=True)
        self._dbusservice.add_path('/System/MinCellVoltage', 3.4, writeable=True)
        self._dbusservice.add_path('/System/MinTemperatureCellId', "C6", writeable=True)
        self._dbusservice.add_path('/System/MinVoltageCellId', "C3", writeable=True)
        self._dbusservice.add_path('/System/NrOfCellsPerBattery', 16, writeable=True)
        self._dbusservice.add_path('/System/NrOfModulesBlockingCharge', 0, writeable=True)
        self._dbusservice.add_path('/System/NrOfModulesBlockingDischarge', 0, writeable=True)
        self._dbusservice.add_path('/System/NrOfModulesOffline', 0, writeable=True)
        self._dbusservice.add_path('/System/NrOfModulesOnline', 1, writeable=True)
        self._dbusservice.add_path('/System/Temperature1', 15, writeable=True)
        self._dbusservice.add_path('/System/Temperature2', 15, writeable=True)
        self._dbusservice.add_path('/System/Temperature3', 0)
        self._dbusservice.add_path('/System/Temperature4', 0)

# === All code below is to simply run it from the commandline for debugging purposes ===

def main():
    logging.basicConfig(level=logging.DEBUG)

    from dbus.mainloop.glib import DBusGMainLoop

    # Have a mainloop, so we can send/receive asynchronous calls to and from dbus
    DBusGMainLoop(set_as_default=True)

    pvac_output = VirtualBatteryMonitor(
        servicename="com.victronenergy.battery.VirtualBatteryMonitor.ttyO1",
        deviceinstance=0,
        paths={
            "/Ac/Energy/Forward": {"initial": 0, "update": 1},
            "/Position": {"initial": 0, "update": 0},
            "/Nonupdatingvalue/UseForTestingWritesForExample": {"initial": None},
            "/DbusInvalid": {"initial": None},
        },
    )

    logging.info(
        "Connected to dbus, and switching over to GLib.MainLoop() (= event based)"
    )
    mainloop = GLib.MainLoop()
    mainloop.run()


if __name__ == "__main__":
    main()