Add Shelly pseudo charger (#1028)

README.md

@@ -13,7 +13,7 @@ EVCC is an extensible EV Charge Controller with PV integration implemented in [G
 - simple and clean user interface
 - multiple [chargers](#charger):
   - Wallbe, Phoenix (includes ESL Walli), go-eCharger, NRGkick (direct Bluetooth or via Connect device), SimpleEVSE, EVSEWifi, KEBA/BMW, openWB, Mobile Charger Connect and any other charger using scripting
-  - Smart-Home outlets: FritzDECT, Tasmota, TP-Link
+  - Smart-Home outlets: FritzDECT, Shelly, Tasmota, TP-Link
 - multiple [meters](#meter): ModBus (Eastron SDM, MPM3PM, SBC ALE3 and many more), Discovergy (using HTTP plugin), SMA Sunny Home Manager and Energy Meter, KOSTAL Smart Energy Meter (KSEM, EMxx), any Sunspec-compatible inverter or home battery devices (Fronius, SMA, SolarEdge, KOSTAL, STECA, E3DC, ...), Tesla PowerWall
 - wide support of vendor-specific [vehicles](#vehicle) interfaces (remote charge, battery and preconditioning status): Audi, BMW, Ford, Hyundai, Kia, Nissan, Niu, Porsche, Renault, Seat, Skoda, Tesla, Volkswagen, Volvo and any other connected vehicle using scripting
 - [plugins](#plugins) for integrating with hardware devices and home automation: Modbus (meters and grid inverters), HTTP, MQTT, Javascript, WebSockets and shell scripts
@@ -188,6 +188,7 @@ Available charger implementations are:
 
 Smart-Home outlet charger implementations:
 - `fritzdect`: Fritz!DECT 200/210 outlets
+- `shelly`: Shelly outlets 
 - `tasmota`: Tasmota outlets
 - `tplink`: TP-Link HSXXX series outlets
 

detect/definitions.go

@@ -38,6 +38,7 @@ const (
 	taskMeter        = "meter"
 	taskFronius      = "fronius"
 	taskTasmota      = "tasmota"
+	taskShelly       = "shelly"
 	// taskTPLink       = "tplink"
 )
 
@@ -252,7 +253,7 @@ func init() {
 		Type:    tasks.Http,
 		Depends: TaskHttp,
 		Config: map[string]interface{}{
-			"path": "//cm?cmnd=Module",
+			"path": "/cm?cmnd=Module",
 			"jq":   ".Module",
 		},
 	})
@@ -277,4 +278,14 @@ func init() {
 			"jq":   ".version",
 		},
 	})
+
+	taskList.Add(tasks.Task{
+		ID:      taskShelly,
+		Type:    tasks.Http,
+		Depends: TaskHttp,
+		Config: map[string]interface{}{
+			"path": "/shelly",
+			"jq":   ".type",
+		},
+	})
 }

internal/charger/shelly.go

@@ -0,0 +1,129 @@
+package charger
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/andig/evcc/api"
+	"github.com/andig/evcc/util"
+	"github.com/andig/evcc/util/request"
+)
+
+// Shelly api homepage
+// https://shelly-api-docs.shelly.cloud/#common-http-api
+
+// shellyRelayResponse provides the evcc shelly charger enabled information
+type shellyRelayResponse struct {
+	Ison bool `json:"ison,omitempty"`
+}
+
+// shellyStatusResponse provides the evcc shelly charger current power information
+type shellyStatusResponse struct {
+	Meters []struct {
+		Power float64 `json:"power,omitempty"`
+	} `json:"meters,omitempty"`
+}
+
+// Shelly charger implementation
+type Shelly struct {
+	*request.Helper
+	uri          string
+	channel      int
+	standbypower float64
+}
+
+func init() {
+	registry.Add("shelly", NewShellyFromConfig)
+}
+
+// NewShellyFromConfig creates a Shelly charger from generic config
+func NewShellyFromConfig(other map[string]interface{}) (api.Charger, error) {
+	cc := struct {
+		URI          string
+		Channel      int
+		StandbyPower float64
+	}{}
+
+	if err := util.DecodeOther(other, &cc); err != nil {
+		return nil, err
+	}
+
+	if cc.URI == "" {
+		return nil, errors.New("missing uri")
+	}
+
+	return NewShelly(cc.URI, cc.Channel, cc.StandbyPower)
+}
+
+// NewShelly creates Shelly charger
+func NewShelly(uri string, channel int, standbypower float64) (*Shelly, error) {
+	c := &Shelly{
+		Helper:       request.NewHelper(util.NewLogger("shelly")),
+		uri:          strings.TrimRight(uri, "/"),
+		channel:      channel,
+		standbypower: standbypower,
+	}
+
+	return c, nil
+}
+
+// Enabled implements the api.Charger interface
+func (c *Shelly) Enabled() (bool, error) {
+	var resp shellyRelayResponse
+	err := c.GetJSON(fmt.Sprintf("%s/relay/%d", c.uri, c.channel), &resp)
+
+	return resp.Ison, err
+}
+
+// Enable implements the api.Charger interface
+func (c *Shelly) Enable(enable bool) error {
+	var resp shellyRelayResponse
+	onoff := map[bool]string{true: "on", false: "off"}
+	err := c.GetJSON(fmt.Sprintf("%s/relay/%d?turn=%s", c.uri, c.channel, onoff[enable]), &resp)
+
+	switch {
+	case err != nil:
+		return err
+	case enable && !resp.Ison:
+		return errors.New("switchOn failed")
+	case !enable && resp.Ison:
+		return errors.New("switchOff failed")
+	default:
+		return nil
+	}
+}
+
+// MaxCurrent implements the api.Charger interface
+func (c *Shelly) MaxCurrent(current int64) error {
+	return nil
+}
+
+// Status implements the api.Charger interface
+func (c *Shelly) Status() (api.ChargeStatus, error) {
+	power, err := c.CurrentPower()
+	if power > 0 {
+		return api.StatusC, err
+	}
+	return api.StatusB, err
+}
+
+var _ api.Meter = (*Shelly)(nil)
+
+// CurrentPower implements the api.Meter interface
+func (c *Shelly) CurrentPower() (float64, error) {
+	var resp shellyStatusResponse
+	err := c.GetJSON(fmt.Sprintf("%s/%s", c.uri, "status"), &resp)
+	
+	if c.channel >= len(resp.Meters) {
+		return 0, errors.New("invalid channel, power meter missing")
+	}
+	power := resp.Meters[c.channel].Power
+
+	// ignore standby power
+	if power < c.standbypower {
+		power = 0
+	}
+
+	return power, err
+}