Merge pull request #49 from stefanor/smart-bms

Initial support for Lynx Smart BMS

tests/test_lynx_smart_bms.py

@@ -0,0 +1,23 @@
+import pytest
+
+from victron_ble.devices.lynx_smart_bms import LynxSmartBMS, LynxSmartBMSData
+
+
+class TestLynxSmartBMS:
+    def parse_decrypted(self, decrypted: bytes) -> LynxSmartBMSData:
+        parsed = LynxSmartBMS(None).parse_decrypted(decrypted)
+        return LynxSmartBMSData(None, parsed)
+
+    def test_parse(self) -> None:
+        actual = self.parse_decrypted(
+            b"\x00@8\x8b\n\xfa\xff\x95\x15U\x14\x8c\xcf\x02\x00\xff\xb3\xea\xf1t\xd6\xfczHT\xb8\xec\x00\x86\t\xe9\xca"
+        )
+        assert actual.get_battery_temperature() is None
+        assert actual.get_consumed_ah() == 4.4
+        assert actual.get_soc() == 99.5
+        assert actual.get_alarm_flags() == 5205  # ??
+        assert actual.get_io_status() == 5525  # ??
+        assert actual.get_current() == -0.6
+        assert actual.get_voltage() == 26.99
+        assert actual.get_remaining_mins() == 14400
+        assert actual.get_error_flags() == 0

victron_ble/devices/__init__.py

@@ -7,6 +7,7 @@
 from victron_ble.devices.battery_sense import BatterySense, BatterySenseData
 from victron_ble.devices.dc_energy_meter import DcEnergyMeter, DcEnergyMeterData
 from victron_ble.devices.dcdc_converter import DcDcConverter, DcDcConverterData
+from victron_ble.devices.lynx_smart_bms import LynxSmartBMS, LynxSmartBMSData
 from victron_ble.devices.solar_charger import SolarCharger, SolarChargerData
 from victron_ble.devices.vebus import VEBus, VEBusData
 
@@ -22,6 +23,8 @@
     "DcDcConverterData",
     "DcEnergyMeter",
     "DcEnergyMeterData",
+    "LynxSmartBMS",
+    "LynxSmartBMSData",
     "SolarCharger",
     "SolarChargerData",
     "VEBus",
@@ -59,7 +62,7 @@ def detect_device_type(data: bytes) -> Optional[Type[Device]]:
     elif mode == 0x6:  # InverterRS
         pass
     elif mode == 0xA:  # LynxSmartBMS
-        pass
+        return LynxSmartBMS
     elif mode == 0xB:  # MultiRS
         pass
     elif mode == 0x5:  # SmartLithium

victron_ble/devices/base.py

@@ -364,6 +364,7 @@ class ACInState(Enum):
     0xA3CE: "Orion Smart 48V|24V-16A Isolated DC-DC Charger",
     0xA3C7: "Orion Smart 48V|48V-6A Isolated DC-DC Charger",
     0xA3CF: "Orion Smart 48V|48V-8.5A Isolated DC-DC Charger",
+    0xA3E6: "Lynx Smart BMS 1000",
     0x2780: "Victron Multiplus II 12/3000/120-50 2x120V",
     0xC030: "SmartShunt IP65 500A/50mV",
 }

victron_ble/devices/lynx_smart_bms.py

@@ -0,0 +1,104 @@
+from construct import BitsInteger, BitStruct, ByteSwapped, Padding
+
+from victron_ble.devices.base import Device, DeviceData
+
+
+class LynxSmartBMSData(DeviceData):
+    def get_error_flags(self) -> int:
+        """
+        Get the raw error_flags field (meaning not documented).
+        """
+        return self._data["error_flags"]
+
+    def get_remaining_mins(self) -> float:
+        """
+        Return the number of remaining minutes of battery life in minutes
+        """
+        return self._data["remaining_mins"]
+
+    def get_voltage(self) -> float:
+        """
+        Return the voltage in volts
+        """
+        return self._data["voltage"]
+
+    def get_current(self) -> float:
+        """
+        Return the current in amps
+        """
+        return self._data["current"]
+
+    def get_io_status(self) -> int:
+        """
+        Get the raw io_status field (meaning not documented).
+        """
+        return self._data["io_status"]
+
+    def get_alarm_flags(self) -> int:
+        """
+        Get the raw alarm_flags field (meaning not documented).
+        """
+        return self._data["alarm_flags"]
+
+    def get_soc(self) -> float:
+        """
+        Return the state of charge in percentage
+        """
+        return self._data["soc"]
+
+    def get_consumed_ah(self) -> float:
+        """
+        Return the consumed energy in amp hours
+        """
+        return self._data["consumed_ah"]
+
+    def get_battery_temperature(self) -> int:
+        """
+        Return the temperature in Celsius if the aux input is set to temperature
+        """
+        return self._data["battery_temperature"]
+
+
+class LynxSmartBMS(Device):
+    data_type = LynxSmartBMSData
+
+    # https://community.victronenergy.com/questions/187303/victron-bluetooth-advertising-protocol.html
+    # Reverse the entire packet, because non-aligned integers are packed
+    # little-endian
+    PACKET = ByteSwapped(
+        BitStruct(
+            Padding(1),  # unused
+            "battery_temperature" / BitsInteger(7),  # -40..86C
+            "consumed_ah" / BitsInteger(20),  # -104857..0Ah
+            "soc" / BitsInteger(10),  # 0..100%
+            "alarm_flags" / BitsInteger(18),
+            "io_status" / BitsInteger(16),
+            "current" / BitsInteger(16, signed=True),  # -3276.8..3276.6 A
+            "voltage" / BitsInteger(16),  # -327.68..327.66 V
+            "remaining_mins" / BitsInteger(16),  # 0..45.5 days (in mins)
+            "error_flags" / BitsInteger(8),
+        ),
+    )
+
+    def parse_decrypted(self, decrypted: bytes) -> dict:
+        pkt = self.PACKET.parse(decrypted[:20])
+
+        parsed = {
+            "error_flags": pkt.error_flags,
+            "remaining_mins": (
+                pkt.remaining_mins if pkt.remaining_mins != 0xFFFF else None
+            ),
+            "voltage": pkt.voltage / 100 if pkt.voltage != 0x7FFF else None,
+            "current": pkt.current / 10 if pkt.current != 0x7FFF else None,
+            "io_status": pkt.io_status,
+            "alarm_flags": pkt.alarm_flags,
+            "soc": pkt.soc / 10.0 if pkt.soc != 0x3FFF else None,
+            "consumed_ah": pkt.consumed_ah / 10 if pkt.consumed_ah != 0xFFFFF else None,
+            "battery_temperature": (
+                (pkt.battery_temperature - 40)
+                if pkt.battery_temperature != 0x7F
+                else None
+            ),
+        }
+
+        return parsed