DaheimLaden: fix firmware init (#33032)

charger/daheimladen.go

@@ -363,17 +363,24 @@ func (wb *DaheimLaden) getPhases() (int, error) {
 }
 
 func (wb *DaheimLaden) checkStation() error {
-	// first call for fw init
-	if _, err := wb.conn.ReadHoldingRegisters(dlRegEvseMaxCurrent, 22); err != nil {
-		return err
-	}
+	// map may still be zero right after the wake-up call- poll briefly until populated
+	for range 5 {
 		b, err := wb.conn.ReadHoldingRegisters(dlRegEvseMaxCurrent, 22)
 		if err != nil {
-		return api.ErrSponsorRequired
+			return err
 		}
-	// station id starts (dlRegStationId-dlRegEvseMaxCurrent) registers into the block
+
 		s, err := utf16BEBytesAsString(b[2*(dlRegStationId-dlRegEvseMaxCurrent):])
-	if err != nil || s == "" {
+		if err != nil {
+			return err
+		}
+
+		if len(s) == 0 {
+			time.Sleep(200 * time.Millisecond)
+			continue
+		}
+
+		if strings.Contains(strings.ToLower(s), "heidelbridge") {
 			return api.ErrSponsorRequired
 		}
 
@@ -383,11 +390,10 @@ func (wb *DaheimLaden) checkStation() error {
 			}
 		}
 
-	if strings.Contains(strings.ToLower(s), "heidelbridge") {
-		return api.ErrSponsorRequired
+		return nil
 	}
 
-	return nil
+	return api.ErrSponsorRequired
 }
 
 var _ api.Diagnosis = (*DaheimLaden)(nil)