Add notes about negative elevation limits

Author: PaulZC

Firmware/RTK_Everywhere/GNSS_Mosaic.ino

@@ -2433,6 +2433,8 @@ bool GNSS_MOSAIC::setDataBaudRate(uint32_t baud)
 // Set the elevation in degrees
 // Inputs:
 //   elevationDegrees: The elevation value in degrees
+// Notes:
+//   mosaic supports negative elevations, but our firmware only support 0-90
 //----------------------------------------
 bool GNSS_MOSAIC::setElevation(uint8_t elevationDegrees)
 {

Firmware/RTK_Everywhere/GNSS_ZED.ino

@@ -406,7 +406,9 @@ bool GNSS_ZED::configureBase()
                                            settings.ubxMessageRatesBase[x]); // UBLOX_CFG UART1 + 2 = USB
         }
 
-        response &= _zed->addCfgValset(UBLOX_CFG_NAVSPG_INFIL_MINELEV, settings.minElev); // Set minimum elevation
+        // Set minimum elevation
+        // Note: ZED supports negative elevations, but our firmware only allows 0-90
+        response &= _zed->addCfgValset(UBLOX_CFG_NAVSPG_INFIL_MINELEV, settings.minElev);
 
         response &= _zed->sendCfgValset(); // Closing value
 

Firmware/RTK_Everywhere/settings.h

@@ -937,7 +937,9 @@ struct Settings
     uint8_t dynamicModel = 254; // Default will be applied by checkGNSSArrayDefaults
     bool enablePrintRoverAccuracy = true;
     int16_t minCNO = 6;   // Minimum satellite signal level for navigation. ZED-F9P default is 6 dBHz
-    uint8_t minElev = 10; // Minimum elevation (in deg) for a GNSS satellite to be used in NAV
+    // Minimum elevation (in deg) for a GNSS satellite to be used in NAV
+    // Note: we use 8-bit unsigned here, but some platforms (ZED, mosaic-X5) support negative elevation limits
+    uint8_t minElev = 10;
 
     // RTC (Real Time Clock)
     bool enablePrintRtcSync = false;