feat: Enhance MK2 driver with device state management and improved command handling

mk2driver/mk2interface.go

@@ -102,3 +102,57 @@ type SettingsWriter interface {
 	// When enabled, the inverter is prevented from sleeping while switched off.
 	SetStandby(enabled bool) error
 }
+
+type DeviceState byte
+
+const (
+	// DeviceStateChargerOnly enables charging only.
+	DeviceStateChargerOnly DeviceState = 0x02
+	// DeviceStateInverterOnly enables inverter output and disables charging.
+	DeviceStateInverterOnly DeviceState = 0x03
+	// DeviceStateOn enables both inverter and charger.
+	DeviceStateOn DeviceState = 0x04
+	// DeviceStateOff disables inverter and charger.
+	DeviceStateOff DeviceState = 0x05
+)
+
+var DeviceStateNames = map[DeviceState]string{
+	DeviceStateChargerOnly:  "charger_only",
+	DeviceStateInverterOnly: "inverter_only",
+	DeviceStateOn:           "on",
+	DeviceStateOff:          "off",
+}
+
+type RAMVarInfo struct {
+	ID        uint16
+	Scale     int16
+	Offset    int16
+	Factor    float64
+	Signed    bool
+	Supported bool
+}
+
+// ProtocolControl exposes protocol 3.14 command paths for direct MK2 control.
+type ProtocolControl interface {
+	SettingsWriter
+	// GetDeviceState returns the current VE.Bus state using command 0x0E.
+	GetDeviceState() (DeviceState, error)
+	// SetDeviceState sets the VE.Bus state using command 0x0E.
+	SetDeviceState(state DeviceState) error
+	// ReadRAMVarByID reads a RAM variable via command 0x30.
+	ReadRAMVarByID(id uint16) (int16, error)
+	// ReadSettingByID reads a setting via command 0x31.
+	ReadSettingByID(id uint16) (int16, error)
+	// SelectRAMVar selects a RAM variable for follow-up read-selected/write-selected paths.
+	SelectRAMVar(id uint16) error
+	// SelectSetting selects a setting for follow-up read-selected/write-selected paths.
+	SelectSetting(id uint16) error
+	// ReadSelected reads the currently selected value via command 0x35.
+	ReadSelected() (int16, error)
+	// ReadRAMVarInfo reads RAM variable metadata via command 0x36.
+	ReadRAMVarInfo(id uint16) (RAMVarInfo, error)
+	// WriteSettingByID writes a setting via command 0x37.
+	WriteSettingByID(id uint16, value int16) error
+	// WriteRAMVarByID writes a RAM variable via command 0x38.
+	WriteRAMVarByID(id uint16, value int16) error
+}