Added support for SMA device config by serial (#121)

* Added support for SMA device config by serial

- The SMA Home Manager or Energy Meter device can now be either defined via its IP or its serial number
- Only URI or serial number needs to be defined in the config file

* Add fatal error when serial and uri are missing

evcc.dist.yaml

@@ -69,7 +69,8 @@ meters:
     timeout: 3s # kill script after 3 seconds
 - name: sma
   type: sma # SMA Home Manager 2.0 or SMA Energy Meter 30
-  uri: 192.168.1.4 # IP address of the device
+  serial: 1234567890 # Serial number of the device, if this is defined uri is not needed!
+  uri: 192.168.1.4 # IP address of the device, if this is defined serial is not needed!
 - name: sdm
   type: modbus
   model: sdm

meter/sma.go

@@ -19,6 +19,7 @@ const (
 type SMA struct {
 	log     *util.Logger
 	uri     string
+	serial  string
 	power   float64
 	energy  float64
 	powerO  sma.Obis
@@ -32,30 +33,38 @@ type SMA struct {
 // NewSMAFromConfig creates a SMA Meter from generic config
 func NewSMAFromConfig(log *util.Logger, other map[string]interface{}) api.Meter {
 	cc := struct {
-		URI, Power, Energy string
+		URI, Serial, Power, Energy string
 	}{}
 	util.DecodeOther(log, other, &cc)
 
-	return NewSMA(cc.URI, cc.Power, cc.Energy)
+	return NewSMA(cc.URI, cc.Serial, cc.Power, cc.Energy)
 }
 
 // NewSMA creates a SMA Meter
-func NewSMA(uri, power, energy string) api.Meter {
+func NewSMA(uri, serial, power, energy string) api.Meter {
 	log := util.NewLogger("sma ")
 
 	sm := &SMA{
 		log:     log,
 		uri:     uri,
+		serial:  serial,
 		powerO:  sma.Obis(power),
 		energyO: sma.Obis(energy),
 		recv:    make(chan sma.Telegram),
 	}
 
 	if sma.Instance == nil {
-		sma.Instance = sma.New(log, sm.uri)
+		sma.Instance = sma.New(log)
 	}
 
-	sma.Instance.Subscribe(uri, sm.recv)
+	// we only need to subscribe to one of the two possible identifiers
+	if uri != "" {
+		sma.Instance.Subscribe(uri, sm.recv)
+	} else if serial != "" {
+		sma.Instance.Subscribe(serial, sm.recv)
+	} else {
+		log.FATAL.Fatalf("config: missing uri or serial")
+	}
 
 	go sm.receive()
 

meter/sma/listener.go

@@ -93,7 +93,7 @@ type Listener struct {
 }
 
 // New creates a Listener
-func New(log *util.Logger, addr string) *Listener {
+func New(log *util.Logger) *Listener {
 	// Parse the string address
 	gaddr, err := net.ResolveUDPAddr("udp4", multicastAddr)
 	if err != nil {
@@ -178,7 +178,7 @@ func (l *Listener) listen() {
 }
 
 // Subscribe adds a client address and message channel
-func (l *Listener) Subscribe(addr string, c chan<- Telegram) {
+func (l *Listener) Subscribe(identifier string, c chan<- Telegram) {
 	l.mux.Lock()
 	defer l.mux.Unlock()
 
@@ -186,15 +186,15 @@ func (l *Listener) Subscribe(addr string, c chan<- Telegram) {
 		l.clients = make(map[string]chan<- Telegram)
 	}
 
-	l.clients[addr] = c
+	l.clients[identifier] = c
 }
 
 func (l *Listener) send(msg Telegram) {
 	l.mux.Lock()
 	defer l.mux.Unlock()
 
-	for addr, client := range l.clients {
-		if addr == msg.Addr {
+	for identifier, client := range l.clients {
+		if identifier == msg.Addr || identifier == msg.Serial {
 			select {
 			case client <- msg:
 			default: