Added RMS.

api/modem/gps/nmea.go

@@ -30,7 +30,7 @@ const (
 
 	nmeaFlagsMask = (1 << 18) - 1
 
-	collectTimeout = 2 * time.Second
+	collectTimeout = 1 * time.Second
 )
 
 func secondCountDownTimer(title string, logger *log.Logger, t time.Duration) {

api/modem/gps/status.go

@@ -7,10 +7,11 @@ import (
 )
 
 type Status struct {
-	GotResponses         bool `json:"gotResponses"`
-	IsValidData          bool `json:"isValidData"`
-	FoundSatelitesCount  int  `json:"foundSatelitesCount"`
-	ActiveSatelitesCount int  `json:"activeSatelitesCount"`
+	GotResponses         bool    `json:"gotResponses"`
+	IsValidData          bool    `json:"isValidData"`
+	FoundSatelitesCount  int     `json:"foundSatelitesCount"`
+	ActiveSatelitesCount int     `json:"activeSatelitesCount"`
+	Rms                  float32 `json:"rms"` // Root mean square
 }
 
 var StatusNil = Status{
@@ -18,6 +19,7 @@ var StatusNil = Status{
 	IsValidData:          false,
 	FoundSatelitesCount:  0,
 	ActiveSatelitesCount: 0,
+	Rms:                  0,
 }
 
 func (g *gps) GetStatus() (Status, error) {
@@ -46,7 +48,7 @@ checkLoop:
 			return StatusNil, fmt.Errorf("nmea invalid sentence: %s", s)
 		}
 		switch values[0][3:] { // Switch by content
-		case "GSV":
+		case "GSV": // Any satelites
 			g.logger.Println("check GSV")
 			// Check len
 			if len(values) < 17 {
@@ -80,7 +82,7 @@ checkLoop:
 				continue checkLoop
 			}
 			st.FoundSatelitesCount = satCount
-		case "GSA":
+		case "GSA": // Active satelites
 			g.logger.Println("check GSA")
 
 			// Check len
@@ -104,7 +106,7 @@ checkLoop:
 				}
 			}
 			st.ActiveSatelitesCount = max(st.ActiveSatelitesCount, count)
-		case "RMC":
+		case "RMC": // Minimum GPS data
 			g.logger.Println("check RMC")
 			// Check len
 			if len(values) < 12 {
@@ -118,10 +120,30 @@ checkLoop:
 			// 2 - is data valid or not
 			// 3: - other data
 
-			// Msg index
+			// Is valid value
 			if values[2] == "A" {
 				st.IsValidData = true
 			}
+		case "GST":
+			g.logger.Println("check GST")
+			// Check len
+			if len(values) < 8 {
+				g.logger.Println("GST too small values")
+				continue checkLoop
+			}
+
+			// Decode
+			// 0 - msg type
+			// 1 - time
+			// 2 - Root Mean Square
+			// 3: - other data
+
+			rms, err := strconv.ParseFloat(values[2], 32)
+			if err != nil {
+				g.logger.Println("RMS decode:", err.Error())
+				continue checkLoop
+			}
+			st.Rms = float32(rms)
 		}
 	}