Add UART1 read function to get GNSS data

main.c

@@ -39,3 +39,9 @@ void GPIO_PORT_B_init(void)
     UART1_CTL_R |= 0x301;                     // Enable UART1, RX, and TX
 
 }
+
+char UART1_READ(void)
+{
+    while (UART1_FR_R & 0x10);                // Wait until RX FIFO is not empty
+    return (char)UART1_DR_R;                  // Return received data
+}