Add periodic S meter readout and display

README.md

@@ -94,6 +94,7 @@ is up) with the following info:
   - `txpwr`: current transmit power setting in percent
   - `audio`: current status of the audio monitor (see the *Hotkeys* section
     in this README for more information about this feature)
+  - `S meter`: periodically refreshed S meter value
 
 - Second status bar line:
   - `up`: how long the audio/serial connection is active

civcontrol.go

@@ -6,6 +6,7 @@ import (
 )
 
 const civAddress = 0xa4
+const sReadInterval = time.Second
 
 type civOperatingMode struct {
 	name string
@@ -61,7 +62,10 @@ var civBands = []civBand{
 }
 
 type civControlStruct struct {
-	st *serialStream
+	st              *serialStream
+	deinitNeeded    chan bool
+	deinitFinished  chan bool
+	resetSReadTimer chan bool
 
 	state struct {
 		freq             uint
@@ -102,7 +106,7 @@ func (s *civControlStruct) decode(d []byte) {
 	case 0x1c:
 		s.decodeTransmitStatus(payload)
 	case 0x15:
-		s.decodeVd(payload)
+		s.decodeVdAndS(payload)
 	case 0x16:
 		s.decodePreamp(payload)
 	}
@@ -232,16 +236,15 @@ func (s *civControlStruct) decodeTransmitStatus(d []byte) {
 	statusLog.reportPTT(s.state.ptt, s.state.tune)
 }
 
-func (s *civControlStruct) decodeVd(d []byte) {
-	if len(d) < 2 {
+func (s *civControlStruct) decodeVdAndS(d []byte) {
+	if len(d) < 3 {
 		return
 	}
 
 	switch d[0] {
+	case 0x02:
+		statusLog.reportS(int(math.Round(((float64(int(d[1])<<8) + float64(d[2])) / 0x0241) * 18)))
 	case 0x15:
-		if len(d) < 3 {
-			return
-		}
 		statusLog.reportVd(((float64(int(d[1])<<8) + float64(d[2])) / 0x0241) * 16)
 	}
 }
@@ -453,6 +456,23 @@ func (s *civControlStruct) getVd() error {
 	return s.st.send([]byte{254, 254, civAddress, 224, 0x15, 0x15, 253})
 }
 
+func (s *civControlStruct) getS() error {
+	return s.st.send([]byte{254, 254, civAddress, 224, 0x15, 0x02, 253})
+}
+
+func (s *civControlStruct) loop() {
+	for {
+		select {
+		case <-s.deinitNeeded:
+			s.deinitFinished <- true
+			return
+		case <-time.After(sReadInterval):
+			_ = s.getS()
+		case <-s.resetSReadTimer:
+		}
+	}
+}
+
 func (s *civControlStruct) init(st *serialStream) error {
 	s.st = st
 
@@ -479,5 +499,21 @@ func (s *civControlStruct) init(st *serialStream) error {
 	if err := s.getVd(); err != nil {
 		return err
 	}
+	if err := s.getS(); err != nil {
+		return err
+	}
+
+	s.deinitNeeded = make(chan bool)
+	s.deinitFinished = make(chan bool)
+	s.resetSReadTimer = make(chan bool)
+	go s.loop()
 	return nil
 }
+
+func (s *civControlStruct) deinit() {
+	if s.deinitNeeded != nil {
+		s.deinitNeeded <- true
+		<-s.deinitFinished
+	}
+	s.deinitNeeded = nil
+}

serialstream.go

@@ -270,7 +270,10 @@ func (s *serialStream) deinit() {
 		s.deinitNeededChan <- true
 		<-s.deinitFinishedChan
 	}
-	civControl = nil
+	if civControl != nil {
+		civControl.deinit()
+		civControl = nil
+	}
 	s.common.deinit()
 	s.rxSeqBuf.deinit()
 }

statuslog.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"math"
 	"os"
 	"sync"
 	"time"
@@ -22,6 +23,7 @@ type statusLogData struct {
 	preamp     string
 	vd         string
 	txPowerStr string
+	s          string
 
 	startTime time.Time
 	rttStr    string
@@ -155,6 +157,28 @@ func (s *statusLogStruct) reportVd(voltage float64) {
 	s.data.vd = fmt.Sprintf("%.1fV", voltage)
 }
 
+func (s *statusLogStruct) reportS(sValue int) {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+
+	if s.data == nil {
+		return
+	}
+	s.data.s = "S"
+	if sValue <= 9 {
+		s.data.s += fmt.Sprint(sValue)
+	} else {
+		s.data.s += "9+"
+
+		if sValue > 18 {
+			s.data.s += "60"
+		} else {
+			dB := (float64((sValue - 9)) / 9) * 60
+			s.data.s += fmt.Sprint(int(math.Round(dB/10) * 10))
+		}
+	}
+}
+
 func (s *statusLogStruct) reportPTT(ptt, tune bool) {
 	s.mutex.Lock()
 	defer s.mutex.Unlock()
@@ -233,8 +257,12 @@ func (s *statusLogStruct) update() {
 	if s.data.txPowerStr != "" {
 		txPowerStr = " txpwr " + s.data.txPowerStr
 	}
+	var sStr string
+	if s.data.s != "" {
+		sStr = " " + s.data.s
+	}
 	s.data.line1 = fmt.Sprint(s.data.stateStr, " ", fmt.Sprintf("%.6f", float64(s.data.frequency)/1000000),
-		modeStr, filterStr, preampStr, vdStr, txPowerStr, " audio ", s.data.audioStateStr)
+		modeStr, filterStr, preampStr, vdStr, txPowerStr, " audio ", s.data.audioStateStr, sStr)
 
 	up, down, lost, retransmits := netstat.get()
 	lostStr := "0"