Fixed GPS UART implementation

tracker/software/source/drivers/ublox.c

@@ -49,12 +49,10 @@ bool gps_receive_byte(uint8_t *data) {
 		I2C_read8(UBLOX_MAX_ADDRESS, 0xFF, data);
 		return true;
 	}
-#else
-	if((*data = sdGetTimeout(&SD5, TIME_IMMEDIATE)) != MSG_TIMEOUT) {
-	  return true;
-	}
-#endif
     return false;
+#else
+	return sdReadTimeout(&SD5, data, 1, TIME_IMMEDIATE);
+#endif
 }
 
 /**

tracker/software/source/drivers/ublox.h

@@ -38,7 +38,8 @@ typedef enum {
 #define UBLOX_MAX_ADDRESS	    0x42
 
 // You can either use I2C (TRUE) or UART (FALSE)
-#define UBLOX_USE_I2C           TRUE
+#define UBLOX_USE_I2C           FALSE
+#define UBLOX_USE_UART          TRUE
 
 #define isGPSLocked(pos) ((pos)->type == 3 && (pos)->num_svs >= 4 && (pos)->fixOK == true)