diff --git a/src/main.c b/src/main.c
--- a/src/main.c
+++ b/src/main.c
@@ -23,6 +23,8 @@ enum _state
     SYSTEM_WSPRTX, // Wait for timeslot and actually transmit the message
 };
 
+static void __calc_gridloc(char *dst, double lat, double lon);
+
 
 int main(void)
 {
@@ -124,12 +126,12 @@ int main(void)
                     fix_acq_starttime = 0;
                     state = SYSTEM_WSPRTX;
                 }
-                else if(HAL_GetTick() - fix_acq_starttime > 60000)
+                // If no fix in 2 minutes
+                else if(HAL_GetTick() - fix_acq_starttime > 120000)
                 {
                 	  // Flash error code and go to idle probably? or just try forever?
                 	led_blink(4);
                 }
-
             } break;
 
             
@@ -146,7 +148,13 @@ int main(void)
             	{
             		if(HAL_GetTick() < nextwspr_time + 2000)
             		{
-						wspr_transmit();
+            			volatile double latitude_flt = (double)gps_getdata()->latitude / 10000000.0;
+            			volatile double longitude_flt = (double)gps_getdata()->longitude / 10000000.0;
+            			volatile uint8_t grid_locator[7];
+
+            			__calc_gridloc(grid_locator, latitude_flt, longitude_flt);
+
+						wspr_transmit(grid_locator);
 						last_wspr_tx_time = HAL_GetTick();
 						state = SYSTEM_IDLE;
             		}
@@ -176,5 +184,32 @@ int main(void)
 }
 
 
+static void __calc_gridloc(char *dst, double lat, double lon)
+{
+	int o1, o2, o3;
+	int a1, a2, a3;
+	double remainder;
+	// longitude
+	remainder = lon + 180.0;
+	o1 = (int)(remainder / 20.0);
+	remainder = remainder - (double)o1 * 20.0;
+	o2 = (int)(remainder / 2.0);
+	remainder = remainder - 2.0 * (double)o2;
+	o3 = (int)(12.0 * remainder);
 
+	// latitude
+	remainder = lat + 90.0;
+	a1 = (int)(remainder / 10.0);
+	remainder = remainder - (double)a1 * 10.0;
+	a2 = (int)(remainder);
+	remainder = remainder - (double)a2;
+	a3 = (int)(24.0 * remainder);
+	dst[0] = (char)o1 + 'A';
+	dst[1] = (char)a1 + 'A';
+	dst[2] = (char)o2 + '0';
+	dst[3] = (char)a2 + '0';
+	dst[4] = (char)o3 + 'A';
+	dst[5] = (char)a3 + 'A';
+	dst[6] = (char)0;
+}