Add enableGnssToUsbSerial setting and toggle code in menuSystem

The default value of false causes status and debug messages to be sent
to the USB serial port (previous behavior).  Setting this value to true
stops the USB serial port from outputting status and debug messages and
instead the USB serial port outputs GNSS data.

Later PRs will implement the behavior described above. This PR
introduces the setting, displays the setting upon menuSystem entry and
changes to setting.enableGnssToUsbSerial in the operations menu.

Author: LeeLeahy2

Firmware/RTK_Everywhere/menuSystem.ino

@@ -156,6 +156,13 @@ void menuSystem()
         systemPrintf("Filtered by parser: %d NMEA / %d RTCM / %d UBX\r\n", failedParserMessages_NMEA,
                      failedParserMessages_RTCM, failedParserMessages_UBX);
 
+        // Display the USB serial output status
+        menuSystemDisplayUsbSerialOutput(settings.enableGnssToUsbSerial);
+
+        //---------------------------
+        // Start of menu
+        //---------------------------
+
         systemPrintln();
         systemPrintln("Menu: System");
         // Separate the menu from the status
@@ -916,6 +923,9 @@ void menuOperation()
         // ZED
         systemPrintln("10) Mirror ZED-F9x's UART1 settings to USB");
 
+        // USB Serial
+        systemPrintln("11) Output GNSS data to USB serial");
+
         systemPrintln("----  Interrupts  ----");
         systemPrint("30) Bluetooth Interrupts Core: ");
         systemPrintln(settings.bluetoothInterruptsCore);
@@ -1017,6 +1027,12 @@ void menuOperation()
                 systemPrintln(F("USB messages successfully enabled"));
         }
 
+        else if (incoming == 11)
+        {
+            settings.enableGnssToUsbSerial ^= 1;
+            menuSystemDisplayUsbSerialOutput(settings.enableGnssToUsbSerial);
+        }
+
         else if (incoming == 30)
         {
             getNewSetting("Not yet implemented! - Enter Core used for Bluetooth Interrupts", 0, 1,
@@ -1069,6 +1085,15 @@ void menuOperation()
     clearBuffer(); // Empty buffer of any newline chars
 }
 
+// Display the USB serial output
+void menuSystemDisplayUsbSerialOutput(bool gnssData)
+{
+    if (gnssData)
+        systemPrintln("USB Serial output is GNSS data");
+    else
+        systemPrintln("USB Serial output is status and debug messages");
+}
+
 // Toggle periodic print message enables
 void menuPeriodicPrint()
 {

Firmware/RTK_Everywhere/settings.h

@@ -976,7 +976,7 @@ typedef struct
     const uint32_t frequency; // L-Band frequency, Hz, if supported. 0 if not supported
 } Regional_Information;
 
-const Regional_Information Regional_Information_Table[] = 
+const Regional_Information Regional_Information_Table[] =
 {
     { "US", "us", { 50.0,  25.0, -60.0, -125.0}, 1556290000 },
     { "EU", "eu", { 72.0,  36.0,  32.0,  -11.0}, 1545260000 },
@@ -1323,6 +1323,8 @@ struct Settings
     bool enableEspNow = false;
     uint8_t wifiChannel = 1; //Valid channels are 1 to 14
 
+    bool enableGnssToUsbSerial = false;
+
     // Add new settings above <------------------------------------------------------------>
     // Then also add to rtkSettingsEntries below
 
@@ -1625,6 +1627,8 @@ const RTK_Settings_Entry rtkSettingsEntries[] = {
     { & settings.enableEspNow, "enableEspNow", _bool, 0, false, true, true },
     { & settings.wifiChannel, "wifiChannel", _uint8_t, 0, false, true, true },
 
+    { & settings.enableGnssToUsbSerial, "enableGnssToUsbSerial", _bool, 0, false, true, true },
+
     // Add new settings above <------------------------------------------------------------>
     /*
     { & settings., "", , 0, false, true },