add jpeg_decode conditional

cubesatsim/cubesatsim.ino

@@ -265,7 +265,7 @@ void loop() {
 //      char output_file2[] = "/cam2.bin"; 	  
       char output_file[] = "/cam.bin"; 
 //      jpeg_decode(image_file, output_file, true); // debug_mode);
-      jpeg_decode(input_file, output_file, false); // debug_mode);
+      if (jpeg_decode(input_file, output_file, false)) {  // only transmit if jpeg decode successful
 	      show_dir();	  
 	//      char telem_display[] = " BATT:    STATUS:   TEMP:  ";	  
 
@@ -294,7 +294,7 @@ void loop() {
 
 	      if (debug_mode)	  
 		Serial.println("\nImage sent!");
-	  
+      }  
   } 
   else
       Serial.println("Unknown mode!");