wip

Signed-off-by: Thomas Klaehn <tkl@blackfinn.de>

alphaess.go

@@ -54,12 +54,8 @@ type AlphaEss struct {
 	client *modbus.ModbusClient
 }
 
-func NewAlphaEss(cfg AlphaConf) (*AlphaEss, error) {
+func NewAlphaEss(cfg AlphaConf) *AlphaEss {
-	a := &AlphaEss{cfg: cfg}
+	return &AlphaEss{cfg: cfg} // connect lazily on first Poll
-	if err := a.connect(); err != nil {
-		return nil, err
-	}
-	return a, nil
 }
 
 func (a *AlphaEss) connect() error {
@@ -100,9 +96,14 @@ func (a *AlphaEss) readReg(r alphaReg) (float32, error) {
 	return float32(raw) * r.factor, nil
 }
 
-// Poll reads all AlphaEss registers. On connection error it attempts one
+// Poll reads all AlphaEss registers. Connects on first call; on error
-// reconnect before returning the error.
+// attempts one reconnect before returning.
 func (a *AlphaEss) Poll() (*InverterData, error) {
+	if a.client == nil {
+		if err := a.connect(); err != nil {
+			return nil, err
+		}
+	}
 	data, err := a.poll()
 	if err != nil {
 		log.Printf("alphaess poll error, reconnecting: %v", err)

main.go

@@ -31,10 +31,7 @@ func main() {
 	}
 	defer db.Close()
 
-	alpha, err := NewAlphaEss(cfg.AlphaEss)
+	alpha := NewAlphaEss(cfg.AlphaEss)
-	if err != nil {
-		log.Fatalf("alphaess: %v", err)
-	}
 	defer alpha.Close()
 
 	meters, err := NewMeterPoller(cfg.MQTT)