Alphatec: fix enable (#10142)

charger/alphatec.go

@@ -2,7 +2,7 @@ package charger
 
 // LICENSE
 
-// Copyright (c) 2019-2022 andig
+// Copyright (c) 2019-2023 andig, premultiply
 
 // This module is NOT covered by the MIT license. All rights reserved.
 
@@ -32,13 +32,12 @@ import (
 
 // Alphatec charger implementation
 type Alphatec struct {
-	conn   *modbus.Connection
-	status api.ChargeStatus
+	conn *modbus.Connection
+	curr uint16
 }
 
 const (
 	alphatecRegStatus     = 0
-	alphatecRegEnable     = 4
 	alphatecRegAmpsConfig = 5
 )
 
@@ -83,70 +82,86 @@ func NewAlphatec(uri, device, comset string, baudrate int, proto modbus.Protocol
 	conn.Logger(log.TRACE)
 
 	wb := &Alphatec{
-		conn:   conn,
-		status: api.StatusB,
+		conn: conn,
+		curr: 6,
+	}
+
+	// get initial state from charger
+	curr, err := wb.getCurrent()
+	if err != nil {
+		return nil, fmt.Errorf("current limit: %w", err)
+	}
+	if curr > 0 {
+		wb.curr = curr
 	}
 
 	return wb, err
 }
 
+func (wb *Alphatec) setCurrent(current uint16) error {
+	b := make([]byte, 2)
+	binary.BigEndian.PutUint16(b, uint16(current))
+
+	_, err := wb.conn.WriteMultipleRegisters(alphatecRegAmpsConfig, 1, b)
+
+	return err
+}
+
+func (wb *Alphatec) getCurrent() (uint16, error) {
+	b, err := wb.conn.ReadHoldingRegisters(alphatecRegAmpsConfig, 1)
+	if err != nil {
+		return 0, err
+	}
+
+	return binary.BigEndian.Uint16(b), nil
+}
+
 // Status implements the api.Charger interface
 func (wb *Alphatec) Status() (api.ChargeStatus, error) {
 	b, err := wb.conn.ReadHoldingRegisters(alphatecRegStatus, 1)
 	if err != nil {
 		return api.StatusNone, err
 	}
 
-	var res api.ChargeStatus
 	switch u := binary.BigEndian.Uint16(b); u {
 	case 1:
-		res = api.StatusA
+		return api.StatusA, nil
 	case 2:
-		res = api.StatusB
+		return api.StatusB, nil
 	case 3:
-		res = api.StatusC
-	case 8:
-		res = wb.status
-		if wb.status == api.StatusC {
-			res = api.StatusB
-		}
+		return api.StatusC, nil
 	default:
 		return api.StatusNone, fmt.Errorf("invalid status: %d", u)
 	}
-
-	wb.status = res
-
-	return res, nil
 }
 
 // Enabled implements the api.Charger interface
 func (wb *Alphatec) Enabled() (bool, error) {
-	b, err := wb.conn.ReadHoldingRegisters(alphatecRegEnable, 1)
-	if err != nil {
-		return false, err
-	}
+	curr, err := wb.getCurrent()
 
-	return binary.BigEndian.Uint16(b) == 0, nil
+	return curr >= 6, err
 }
 
 // Enable implements the api.Charger interface
 func (wb *Alphatec) Enable(enable bool) error {
-	b := make([]byte, 2)
-	if !enable {
-		binary.BigEndian.PutUint16(b, 1)
+	var curr uint16
+	if enable {
+		curr = wb.curr
 	}
 
-	_, err := wb.conn.WriteMultipleRegisters(alphatecRegEnable, 1, b)
-
-	return err
+	return wb.setCurrent(curr)
 }
 
 // MaxCurrent implements the api.Charger interface
 func (wb *Alphatec) MaxCurrent(current int64) error {
-	b := make([]byte, 2)
-	binary.BigEndian.PutUint16(b, uint16(current))
+	if current < 6 {
+		return fmt.Errorf("invalid current %d", current)
+	}
 
-	_, err := wb.conn.WriteMultipleRegisters(alphatecRegAmpsConfig, 1, b)
+	err := wb.setCurrent(uint16(current))
+	if err == nil {
+		wb.curr = uint16(current)
+	}
 
 	return err
 }