Simplify charge meter configuration (#2386)

cmd/demo.yaml

@@ -115,6 +115,5 @@ site:
 loadpoints:
 - title: Carport
   charger: demo
-  meters:
-    charge: charge
+  meter: charge
   vehicle: demo

core/loadpoint.go

@@ -100,8 +100,9 @@ type LoadPoint struct {
 	ChargerRef  string   `mapstructure:"charger"`  // Charger reference
 	VehicleRef  string   `mapstructure:"vehicle"`  // Vehicle reference
 	VehiclesRef []string `mapstructure:"vehicles"` // Vehicles reference
+	MeterRef    string   `mapstructure:"meter"`    // Charge meter reference
 	Meters      struct {
-		ChargeMeterRef string `mapstructure:"charge"` // Charge meter reference
+		ChargeMeterRef string `mapstructure:"charge"` // deprecated
 	}
 	SoC               SoCConfig
 	OnDisconnect_     interface{} `mapstructure:"onDisconnect"`
@@ -198,8 +199,18 @@ func NewLoadPointFromConfig(log *util.Logger, cp configProvider, other map[strin
 	// store defaults
 	lp.collectDefaults()
 
+	if lp.MeterRef != "" {
+		lp.chargeMeter = cp.Meter(lp.MeterRef)
+	}
+
+	// deprecated
 	if lp.Meters.ChargeMeterRef != "" {
-		lp.chargeMeter = cp.Meter(lp.Meters.ChargeMeterRef)
+		lp.log.WARN.Println("meters: charge: is deprecated. Use meter: instead")
+		if lp.chargeMeter == nil {
+			lp.chargeMeter = cp.Meter(lp.Meters.ChargeMeterRef)
+		} else {
+			lp.log.ERROR.Println("must not have meter: and meters: charge: both")
+		}
 	}
 
 	// multiple vehicles

evcc.dist.yaml

@@ -70,8 +70,7 @@ site:
 loadpoints:
 - title: Garage # display name for UI
   charger: wallbe # charger
-  meters:
-    charge: charge # charge meter
+  meter: charge # charge meter
   vehicle: audi
   # vehicles: # use if multiple vehicles allowed to charge on this loadpoint
   # - ID.3