Set serial communication speed based on platform

The Postcard can modify its dataPortBaud (2nd port on CH342) independent of the UART2 comm with the ESP32. This allows the platform to set the

Author: nseidle

Firmware/RTK_Everywhere/Begin.ino

@@ -1027,12 +1027,6 @@ void pinGnssUartTask(void *pvParameters)
     if (settings.printTaskStartStop)
         systemPrintln("Task pinGnssUartTask started");
 
-    if (productVariant == RTK_TORCH)
-    {
-        // Override user setting. Required because beginGnssUart() is called before beginBoard().
-        settings.dataPortBaud = 115200;
-    }
-
     if (serialGNSS == nullptr)
         serialGNSS = new HardwareSerial(2); // Use UART2 on the ESP32 for communication with the GNSS module
 
@@ -1042,9 +1036,24 @@ void pinGnssUartTask(void *pvParameters)
     if (pin_GnssUart_RX == -1 || pin_GnssUart_TX == -1)
         reportFatalError("Illegal UART pin assignment.");
 
-    serialGNSS->begin(settings.dataPortBaud, SERIAL_8N1, pin_GnssUart_RX,
-                      pin_GnssUart_TX); // Start UART on platform depedent pins for SPP. The GNSS will be configured
-                                        // to output NMEA over its UART at the same rate.
+    uint32_t platformGnssCommunicationRate =
+        settings.dataPortBaud; // Default to 230400bps for ZED. This limits GNSS fixes at 4Hz but allows SD buffer to be
+                               // reduced to 6k.
+
+    if (productVariant == RTK_TORCH)
+    {
+        // Override user setting. Required because beginGnssUart() is called before beginBoard().
+        platformGnssCommunicationRate = 115200;
+    }
+    else if (productVariant == RTK_POSTCARD)
+    {
+        // LG290P communicates at 460800bps.
+        platformGnssCommunicationRate = 115200 * 4;
+    }
+
+    serialGNSS->begin(platformGnssCommunicationRate, SERIAL_8N1, pin_GnssUart_RX,
+                      pin_GnssUart_TX); // Start UART on platform dependent pins for SPP. The GNSS will be
+                                        // configured to output NMEA over its UART at the same rate.
 
     // Reduce threshold value above which RX FIFO full interrupt is generated
     // Allows more time between when the UART interrupt occurs and when the FIFO buffer overruns