Changed PM polling frequency for Open Air to 2s

examples/Open_Air/Open_Air.ino

@@ -98,7 +98,7 @@ enum {
 #define SENSOR_CO2_CALIB_COUNTDOWN_MAX 5     /** sec */
 #define SENSOR_TVOC_UPDATE_INTERVAL 1000     /** ms */
 #define SENSOR_CO2_UPDATE_INTERVAL 5000      /** ms */
-#define SENSOR_PM_UPDATE_INTERVAL 5000       /** ms */
+#define SENSOR_PM_UPDATE_INTERVAL 2000       /** ms */
 #define SENSOR_TEMP_HUM_UPDATE_INTERVAL 2000 /** ms */
 #define DISPLAY_DELAY_SHOW_CONTENT_MS 2000   /** ms */
 #define WIFI_HOTSPOT_PASSWORD_DEFAULT                                          \