Sensors Page

This page is used to select which sensors the app uses to tell what is happening in the area. There are five main sources to select from:

• Internal GPS - enables using the Android device's internal GPS receiver to determine position information.
  
• Bluetooth GPS/ADS-B - enables receiving GPS and/or ADS-B information from an external device over a Bluetooth connection. There are two selections available so you can have two bluetooth devices (eg, one GPS and one ADS-B).
  • The very first time you are going to use a particular device with this Android, you must pair it by going to the Android's settings page, then find Bluetooth (possibly under Wireless & Networks). You may then have to click some button to get the new device to show up. Then follow the prompts to get it to pair up. Once successfully paired, it does not need to be paired up again.
  • Once the device is paired up, select it from the (select) box. If the device isn't listed there, try clicking the Refresh button at the bottom of the selection box.
  • The Secure checkbox is provided for those devices that require a secure connection. If you aren't sure which you need, try one then the other.
  • Once the device is selected and you have set the Secure checkbox one way or the other, check the checkbox by the Bluetooth GPS/ADS-B message and it should connect assuming it is in range and operating.
  • Bluetooth can be picky about connecting so you may have to restart the app after a connection failure to get it to work. To restart the app, click on the Android's menu button then select Exit then re-open the app. It may also help to turn the device you are trying to connect with off then back on.
  • Once the device starts sending data to the app, the status message below the Secure checkbox will start counting the number of bytes received.
  
• WiFi UDP GPS/ADS-B - enables receiving GPS and/or ADS-B information from an external device over a WiFi UDP port. More than one external device can send information to the app at a time using the same UDP port. There are two selections available so you can have two different UDP ports if necessary.
  • Enter the port number your device will be sending on in the port box. For example, Stratux seems to like port 4000.
  • Check the checkbox next to the WiFi UDP GPS/ADS-B message and it should start listening for inbound packets.
  • There is no connection as such as there is with Bluetooth or TCP, but the status message below the port number box should start counting bytes as it receives packets.
  
• WiFi TCP GPS/ADS-B - enables receiving GPS and/or ADS-B information from an external device over a WiFi TCP connection. More than one external device can send information to the app at a time using the same TCP port. There are two selections available so you can have two different TCP ports if necessary.
  • Enter the port number your device will be sending on in the port box.
  • Check the checkbox next to the WiFi TCP GPS/ADS-B message and it should start listening for inbound connections.
  • The status message box below the port number will indicate how many inbound connections have been established, so you can see if your device has connected or not.
• Simulator - generates GPS positions from a given starting point, speed, heading, altitude, turn rate and climb rate. Overrides all other GPS sources when enabled, and flashes the border in yellow. Updates only when page other than Sensors is open.

NOTE: You should only have just one source of GPS information enabled at a time so the app doesn't receive closely spaced (distance-wise and time-wise) readings.

The Bluetooth and WiFi types accept dump1090, dump978, GDL-90 and NMEA packets in any mix.

• dump1090 is a program available on the Internet that decodes ADS-B packets received from an SDR (software defined radio). The author has successfully used it with a Linux-based Raspberry PI. The computer (Raspberry PI) runs the dump1090 program then pipes the data to an Android WiFi TCP port using nc (netcat) or similar program. It can either literally use WiFi or can use adb forward to send the data over a USB cable between the laptop and the Android device as the WiFi may be unreliable.
• dump978 is a program available on the Internet that decodes ADS-B packets received from an SDR (software defined radio). The author has successfully used it with a Windows-based laptop and with a Linux-based Raspberry PI. The computer (laptop or Raspberry PI) runs the rtl_sdr and dump978 programs then pipes the data to an Android WiFi TCP port using nc (netcat) or similar program. It can either literally use WiFi or can use adb forward to send the data over a USB cable between the laptop and the Android device as the WiFi may be unreliable. WairToNow currently processes basic, long and uplink message types.
• GDL-90 is a protocol used by ADS-B equipment to send ADS-B information to display devices. WairToNow currently processes basic, heartbeat, long, ownship, ownship/geoalt, traffic, and uplink messages.
• NMEA is a protocol used by GPS equipment to send GPS position information to display devices. WairToNow currently processes GGA, GSV, RMC, RTM and VTG messages.