Add support for querying S meter overflow

README.md

@@ -85,7 +85,8 @@ kappanhang displays a "realtime" status bar (when the audio/serial connection
 is up) with the following info:
 
 - First status bar line:
-  - `S meter`: periodically refreshed S meter value
+  - `S meter`: periodically refreshed S meter value, OVF is displayed on
+    overflow
 
 - Second status bar line:
   - `state`: RX/TX/TUNE depending on the PTT status
@@ -108,7 +109,7 @@ is up) with the following info:
   - `lost`: lost audio/serial packet count from the server
 
 Data for the first 2 status bar lines are acquired by monitoring CiV traffic
-in the serial stream. S value is queried periodically.
+in the serial stream. S value and OVF are queried periodically.
 
 `retx` and `lost` are displayed in a 1 minute window, which means they will be
 reset to 0 if they don't increase for 1 minute. A `retx` value other than 0

civcontrol.go

@@ -105,7 +105,7 @@ func (s *civControlStruct) decode(d []byte) {
 	case 0x10:
 		s.decodeTS(payload)
 	case 0x1a:
-		s.decodeDataMode(payload)
+		s.decodeDataModeAndOVF(payload)
 	case 0x14:
 		s.decodePower(payload)
 	case 0x1c:
@@ -218,23 +218,35 @@ func (s *civControlStruct) decodeTS(d []byte) {
 	statusLog.reportTS(s.state.ts)
 }
 
-func (s *civControlStruct) decodeDataMode(d []byte) {
-	if len(d) < 3 || d[0] != 0x06 {
+func (s *civControlStruct) decodeDataModeAndOVF(d []byte) {
+	if len(d) < 2 {
 		return
 	}
 
-	var dataMode string
-	var filter string
-	if d[1] == 1 {
-		dataMode = "-D"
-		s.state.dataMode = true
-		s.state.filterIdx = s.decodeFilterValueToFilterIdx(d[2])
-		filter = civFilters[s.state.filterIdx].name
-	} else {
-		s.state.dataMode = false
-	}
+	switch d[0] {
+	case 0x06:
+		if len(d) < 3 {
+			return
+		}
+		var dataMode string
+		var filter string
+		if d[1] == 1 {
+			dataMode = "-D"
+			s.state.dataMode = true
+			s.state.filterIdx = s.decodeFilterValueToFilterIdx(d[2])
+			filter = civFilters[s.state.filterIdx].name
+		} else {
+			s.state.dataMode = false
+		}
 
-	statusLog.reportDataMode(dataMode, filter)
+		statusLog.reportDataMode(dataMode, filter)
+	case 0x09:
+		if d[1] != 0 {
+			statusLog.reportOVF(true)
+		} else {
+			statusLog.reportOVF(false)
+		}
+	}
 }
 
 func (s *civControlStruct) decodePower(d []byte) {
@@ -539,6 +551,10 @@ func (s *civControlStruct) getS() error {
 	return s.st.send([]byte{254, 254, civAddress, 224, 0x15, 0x02, 253})
 }
 
+func (s *civControlStruct) getOVF() error {
+	return s.st.send([]byte{254, 254, civAddress, 224, 0x1a, 0x09, 253})
+}
+
 func (s *civControlStruct) getTS() error {
 	return s.st.send([]byte{254, 254, civAddress, 224, 0x10, 253})
 }
@@ -551,6 +567,7 @@ func (s *civControlStruct) loop() {
 			return
 		case <-time.After(sReadInterval):
 			_ = s.getS()
+			_ = s.getOVF()
 		case <-s.resetSReadTimer:
 		}
 	}
@@ -585,6 +602,9 @@ func (s *civControlStruct) init(st *serialStream) error {
 	if err := s.getS(); err != nil {
 		return err
 	}
+	if err := s.getOVF(); err != nil {
+		return err
+	}
 	if err := s.getTS(); err != nil {
 		return err
 	}

statuslog.go

@@ -24,6 +24,7 @@ type statusLogData struct {
 	vd        string
 	txPower   string
 	s         string
+	ovf       bool
 	ts        string
 
 	startTime time.Time
@@ -55,6 +56,8 @@ type statusLogStruct struct {
 			monOn string
 			rec   string
 		}
+
+		ovf string
 	}
 
 	data *statusLogData
@@ -168,6 +171,16 @@ func (s *statusLogStruct) reportS(sValue string) {
 	s.data.s = sValue
 }
 
+func (s *statusLogStruct) reportOVF(ovf bool) {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+
+	if s.data == nil {
+		return
+	}
+	s.data.ovf = ovf
+}
+
 func (s *statusLogStruct) reportTS(ts uint) {
 	s.mutex.Lock()
 	defer s.mutex.Unlock()
@@ -249,7 +262,11 @@ func (s *statusLogStruct) update() {
 	s.mutex.Lock()
 	defer s.mutex.Unlock()
 
-	s.data.line1 = fmt.Sprint(s.data.s)
+	var ovfStr string
+	if s.data.ovf {
+		ovfStr = " " + s.preGenerated.ovf
+	}
+	s.data.line1 = fmt.Sprint(s.data.s, ovfStr)
 
 	var tsStr string
 	if s.data.ts != "" {
@@ -396,6 +413,10 @@ func (s *statusLogStruct) initIfNeeded() {
 	s.preGenerated.stateStr.tune = c.Sprint(" TUNE ")
 	s.preGenerated.audioStateStr.rec = c.Sprint("  REC  ")
 
+	c = color.New(color.FgHiWhite)
+	c.Add(color.BgRed)
+	s.preGenerated.ovf = c.Sprint(" OVF ")
+
 	s.preGenerated.retransmitsColor = color.New(color.FgHiWhite)
 	s.preGenerated.retransmitsColor.Add(color.BgYellow)
 	s.preGenerated.lostColor = color.New(color.FgHiWhite)