Configuring AIRS

Pressing the Config tab in the main AIRS view presents you with multiple options for configuring AIRS:

(for versions before Android 3.0)

(versions after Android 3.0)

Selecting Sensors

After pressing Select Sensors, you are presented with the following screen:


This screen shows all the discovered sensors that the device offers for sensing. Each line displays the sensor symbol (e.g., Az) with the description for each sensor in brackets (e.g., Azimuth).

You can select each sensor for sensing by clicking the checkmark next to it. The selection is stored permanently when starting the sensing and will be available at the start of another sensing session or you can save it with the full AIRS configuration as a template (see below). This allows for using the same settings multiple times.





When pressing the Options key of your device, you will see the menu with the following options:

  • Help: shows a brief Help dialog
  • Select All: marks all sensors as selected (careful, this will record a lot of information)
  • Unselect All: marks all sensors as being selected (for a clean selection, for instance)




  • Info: shows a dialogue box with a list of all discovered sensors with description, unit of measurement as well as minimum and maximum expected value for the measurements, such as in this picture.

Once you are done with selecting sensors, go back to the Config menu with the Back key.

General Settings

Pressing the General Settings entry will enable you to configure several options in the following preference screen. You can also display a brief description of each option when selecting the About menu item (press your Android Options key):

Screenshot_2013-10-03-17-41-17 Screenshot_2013-10-03-17-35-16

For the remote sensing sessions, you can configure the following settings:

  • Server Name: this is the DNS name or IP address of your AIRS application server that is being used. Note that the server needs to be publicly accessible in order to be reachable by the AIRS mobile client;
  • Server port: this is the port number being used by the AIRS application server (such as 9000).

For the local sensing sessions, you can configure the following settings:

  • Local Display: a local session always starts a background service that performs the sensing itself. Here you can configure whether or not the background service keeps track of the last value for each sensor being sensed. Otherwise, only the number of sensed values is kept. Battery-wise, there is hardly any impact when enabling this function – this is of course under the assumption that you are not displaying the values themselves, which DOES require additional battery.
  • Local Storage: AIRS can store the sensor values in a SQLite database, which is more secure than individual text files. During the synchronization of the recordings, individual text files are created with a maximum file size being defined in the next setting. These files are stored in /AIRS_temp/ on the internal storage.
  • AIRS Intents: apart from storing locally recorded values in the internal SQLite database, AIRS can also send the sensor value (and the symbol) via an Android broadcast intent. This allows other programs to efficiently listen to recordings of particular sensors without needing to frequently crawl the SQLite database (which in itself is only possible when sharing the userID and certificate with AIRS). This option is used by the AIRS Ruler to trigger certain actions based on values recorded in AIRS. Switch this option off and your recordings will be entirely private!
  • Wakeup: Android devices usually sleep when the screen switches off. This is to preserve battery. With this, however, AIRS will stop sensing most sensor values, too. This can be desired, i.e., in scenarios in which user activity is of interest, not the activity when the device is not used. IF you want to continuously sense values, you will need to keep the device awake (through a so-called wake-lock), which you can enable by this setting.
  • Battery Kill Condition: Allows for setting a battery level for killing AIRS recording (remote or local) in case that the battery falls below that value. This allows for saving spare capacity when you are out and about.

Since AIRS V2.7, you can regularly upload recordings as text files to your Google Drive account (the syntax of the text files is the same as for manual synchronisation). The settings for this regular upload are defined here:

  • Google Account: define the Google account on your device that is used for the upload. After selection, AIRS will try to create a directory called “AIRS recordings” on your drive.
  • Upload Frequency: you can disable the upload here or define a hourly, daily or weekly schedule for the upload
  • Upload via WiFi only: check if you want AIRS to only upload over WiFi connection.

There are also general settings which apply to both remote and local sensing:

  • Reminder interval: AIRS can inform you about an ongoing sensing session through a brief vibration and/or LED notification (on supported devices only). Here, you select the interval for this vibration. If you select ‘0’ as a value, the vibration is switched off. Note that you will always have a notification bar indication that AIRS is running!
  • Vibrate: check if you want a vibration reminder
  • Lights: check if you want a LED/light reminder
  • LED Color: choose from a set of LED colours
  • Debug: AIRS debugs several parts of the program. Here you switch the debugging on and off. Debug messages will be stored in the main directory of the SD card under the file name AIRS_log.txt. Debugging will consume more battery and slightly slow down AIRS!

Handler Settings

AIRS provides settings for various types of inputs, such as device information, environmental, location and so on. There is a small help text under each category.


Device Information


The following settings are provided for device-related input types:

  • Orientation Interval: determines the polling interval for the orientation sensors azimuth, roll, and pitch
  • Proximity Interval: determines the polling interval for the proximity sensor
  • System Poll Interval: determines the polling interval for the system sensors like RAM and task lists
Environmental Sensors


Settings for various environmental sensors, such as phone-internal barometer (if supported), ambient light as well as from Internet-provided weather information:

  • Sensor Interval: sampling frequency [in seconds] for the phone-internal sensors, such as barometer and light
  • Weather Interval: time between weather updates in minutes (less makes little sense)
  • GPS Accuracy: Update weather only when moved more than a given distance since the last weather update. The weather sensors automatically utilize WiFi and cell location since the accuracy can only be set above 1km (less makes little sense since no weather database has more fine grained detail). However, setting the value to zero always determines the weather at the given location, having moved or not! The weather information uses an Internet-provided weather API for your location. If there is no connectivity, the sensor does not perform location determination. If there is no connectivity for longer than the determined interval, the handler sleeps and determines location and weather cca. 2 seconds after connectivity becomes available.
Audio Sampling

The following settings are provided for the ambient noise level:

  • Sampling rate: determines the rate with which the surrounding noise level is sampled – a selection of choices is provided
  • Sampling interval: determines the interval in seconds for repeating the measurements (a sampling lasts for about one second after which the sensor waits for the here defined seconds before sampling again).
  • Sound Pressure Adjustment: sets the adjustment being used for the sound pressure level measurement (AA sensor). This needs to be done based on a calibrated sound meter. Such adjustment is necessary due to the differences in hardware in each phone, such as microphone, DAC and others.


The following settings are provided for the location determination:

  • Enable GPS: decides whether or not the GPS sensors will appear in the discovery dialogue
  • Use Network Location: enables the use of Wifi and cell locations, which can save power if this information is available
  • GPS Interval: determines the GPS polling interval in seconds. If there is a change within the defined accuracy, values can be delivered earlier than defined (e.g., during driving at higher speed)
  • GPS Accuracy: determines the GPS accuracy in meters with which new values new should be reported. If there are no changes within the defined accuracy, no values are reported even if the interval exceeds.
  • AGPS Refresh Interval: on some phones, the ephemeral information for assisted GPS can be forced to be updated frequently. This increases accuracy in times when you travel larger distances as well as in adverse situations (e.g., cloudy). You can specify the interval for a refresh of this information here.
  • Adaptive GPS: the adaptive mode switches off GPS recording when near a set of defined WiFi access points. This greatly saves battery in cases where you are often nearby such WiFis. However, it will introduce a possible delay in GPS recording when you leave the WiFi zone since GPS will need to acquire a fix from the satellites.
  • WiFi Selection: this will bring up the list of WiFi access points that you connected to (the same list you can find in your system settings). You can select those WiFi APs near which you want to disable GPS in the adaptive GPS mode (see last bullet)
  • Most Visited WiFis: this will determine a list of most visited WiFi APs in the last week (you can change this duration to one month after the dialog appears). The APs you already selected as being used for adaptive GPS are marked in the list. You can select any other AP according to their ranking. Long-pressing any of the entries will shown you how often you visited this AP during the past week (or month). Visits here stands for how often the AP was detected when scanning for the WI sensor. Please note that it is not advisable to simply mark all the most visited APs since some of these APs might not be associated with a clear location (e.g., when being the SSID of a WiFi provider such as eduroam or BTWiFi in the list below). Hence, choose WiFi APs that are more clearly associated with a specific location (such as wgb in the list below, the WiFi in the Computer Laboratory of Cambridge University)
  • Enable Wifi: if Wifi is switched off when AIRS starts, this switch can have AIRS switch on Wifi for measurements. Otherwise, no Wifi sensors are provided.
  • Prevent Wifi sleep: this option sets a partial wake lock on the Wifi, preventing a Wifi sleep during the execution of NORS. Typically Wifi is switched off when the screen is off – this setting overrides this! BEWARE: preventing Wifi sleep will increase the battery usage!
  • Wifi Intervaldetermines the Wifi scanning interval – the shorter, the higher the battery usage due to the Wifi scan operation!
Heart Monitor



We currently support integration with the 18_HxMBT-TransparentHxM BT monitor from Zephyr or with BTLE (BT4.0+ or sometimes also called BT Smart) compatible devices such as the Polar P7 or the HxM BT Smart. The following settings are provided:

  • Enable Heartmonitor: enables the use of the monitor. If enabled, the handler will try to connect to the chosen devices when recording is requested
  • Target Device: select the type of device being used, currently supporting the Zephyr HxM BT monitor or BTLE-compatible devices (such as Polar P7). When pressed, a selection dialog appears as shown under the main settings picture on the left.
  • BT Smart Device Selection: Allows for selecting the BTLE-compatible device to be used. For this, you will need to have the device switched on for it to be discovered. After selecting this preference, a window with the list of discovered devices will appear (see image on the left).
  • Zephyr Device selection: allows for selecting the HxM BT monitor device being used. You will need to pair the heart rate monitor beforehand so that the device will show up in the list.
  • Averaging Window: Usually, heart rate values are provided once a second. This will generate many readings when recording over, say a day. To reduce the number of readings, this setting allows for defining a timewindow over which to average the readings, e.g., over 10 seconds.
 BT Beacon

BT is used for determining what and how many BT-enabled devices are around. The following settings are provided:

  • Enable BT: if Bluetooth is switched off when starting AIRS, it can be enabled by AIRS
  • Ask before enabling: if Bluetooth is enabled by AIRS, you can select whether or not the user should be ask before
  • BT interval: the scan interval in seconds before starting another BT scan

AIRS can watch and record calendar events from selected calendars. You can pick the wanted calendars from the list of all of your locally available ones.
IM Notifications


AIRS can record information delivered through notifications from Spotify (through the MP sensor) and from Google Hangout and Skype (through the NO sensor).
In order to be notified about incoming IM notification, you will need to enable the Accessibility service for AIRS under the system setting. This can also be done through the AIRS settings in the IM notifications menu.
Selecting this menu entry will bring you to the system settings. Select the AIRS entry and switch it on. You will see a brief description of the service in the system settings.
Event Button
You can set the maximum number of event descriptions that AIRS will store when you annotate with the AIRS event button widget (sensor EB). You can also enable alphabetical sorting of the event descriptions after you press the Event widget during recording.
Media Folder Watcher
AIRS allows for watching the creation of various media files. Currently, the watching of camera, pictures, videos and music files is supported. In terms of configuration, the handler allows for enabling the various media types being watched. In addition, the user can configure the particular path being used for the watching for each particular type of media. The related recording (delivered as the MW sensor) will provide the media type as well as the file name that has been created.
For the camera path, you can try to use the default path, provided by an Android API. Unfortunately, not all manufacturers implement this API correctly. As a result, you might miss snapshot recordings since the wrong folder is watched. To avoid this, simply select the Camera Path entry and select any of your preferred gallery applications. After the gallery has opened, navigate to the camera directory and select a recently shot picture. After the selection, you will return to AIRS and the path of the  selected image will be stored as the camera path.

Saving the settings


Once you finished with the individual settings, return to the main screen under the Config tab. If you now press the Options key, you are presented with the following screen:

  • Help provides you with a brief set of instructions
  • Save as Template allows for saving your current configuration, including the selection of sensors, as a template