12. AltosDroid¶

AltosDroid provides the same flight monitoring capabilities as AltosUI, but runs on Android devices. AltosDroid is designed to connect to a TeleBT receiver over Bluetooth™ and (on Android devices supporting USB On-the-go) TeleDongle and TeleBT devices over USB. AltosDroid monitors telemetry data, logging it to internal storage in the Android device, and presents that data in a UI similar to the Monitor Flight window in AltosUI.

This manual will explain how to configure AltosDroid, connect to TeleBT or TeleDongle, operate the flight monitoring interface and describe what the displayed data means.

12.1. Installing AltosDroid¶

AltosDroid is available from the Google Play store. To install it on your Android device, open the Google Play Store application and search for “altosdroid”. Make sure you don’t have a space between “altos” and “droid” or you probably won’t find what you want. That should bring you to the right page from which you can download and install the application.

12.2. Charging TeleBT Battery¶

Before using TeleBT with AltosDroid, make sure the internal TeleBT battery is charged. To do this, attach a micro USB cable from a computer or other USB power source to TeleBT. A dual LED on the circuit board should illuminate, showing red while the battery is charging, green when charging is completed, and both red and green on at the same time if there is a battery fault.

12.3. Connecting to TeleBT over Bluetooth™¶

Press the Android Menu button or soft-key to see the configuration options available. Select the Connect a device option and then the Scan for devices entry at the bottom to look for your TeleBT device. Select your device, and when it asks for the code, enter 1234.

Subsequent connections will not require you to enter that code, and your paired device will appear in the list without scanning.

12.4. Connecting to TeleDongle or TeleBT over USB¶

Get a special USB On-the-go adapter cable. These cables have a USB micro-B male connector on one end and a standard A female connector on the other end. Plug in your TeleDongle or TeleBT device to the adapter cable and the adapter cable into your phone and AltosDroid should automatically start up. If it doesn’t, the most likely reason is that your Android device doesn’t support USB On-the-go.

12.5. Configuring AltosDroid¶

There are several configuration and operation parameters available in the AltosDroid menu.

Select radio frequency: This selects which frequency to listen on by bringing up a menu of pre-set radio frequencies. Pick the one which matches your altimeter.
Select data rate: Altus Metrum transmitters can be configured to operate at lower data rates to improve transmission range. If you have configured your device to do this, this menu item allows you to change the receiver to match.
Change units: This toggles between metric and imperial units.
Load maps: Brings up a dialog allowing you to download offline map tiles so that you can have maps available even if you have no network connectivity at the launch site.
Map type: Displays a menu of map types and lets you select one. Hybrid maps include satellite images with a roadmap overlaid. Satellite maps dispense with the roadmap overlay. Roadmap shows just the roads. Terrain includes roads along with shadows indicating changes in elevation, and other geographical features.
Toggle Online/Offline maps: Switches between online and offline maps. Online maps will show a move to current position icon in the upper right corner, while offline maps will have copyright information all over the map. Otherwise, they’re pretty similar.
Select Tracker: Switches the information displays to show data for a different transmitting device. The map will always show all of the devices in view. Trackers are shown and selected by serial number, so make sure you note the serial number of devices in each airframe.
Delete Track: Deletes all information about a transmitting device.

12.6. AltosDroid Flight Monitoring¶

AltosDroid is designed to mimic the AltosUI flight monitoring display, providing separate tabs for each stage of your rocket flight along with a tab containing a map of the local area with icons marking the current location of the altimeter and the Android device.

12.7. Pad¶

The Pad tab shows information used to decide when the rocket is ready for flight. The first elements include red/green indicators, if any of these is red, you’ll want to evaluate whether the rocket is ready to launch.

When the pad tab is selected, the voice responses will include status changes to the igniters and GPS reception, letting you know if the rocket is still ready for launch.

Battery: This indicates whether the Li-Po battery powering the transmitter has sufficient charge to last for the duration of the flight. A value of more than 3.8V is required for a GO status.
Receiver Battery: This indicates whether the Li-Po battery powering the TeleBT has sufficient charge to last for the duration of the flight. A value of more than 3.8V is required for a GO status.
Data Logging: This indicates whether there is space remaining on-board to store flight data for the upcoming flight. If you’ve downloaded data, but failed to erase flights, there may not be any space left. TeleMetrum and TeleMega can store multiple flights, depending on the configured maximum flight log size. TeleGPS logs data continuously. TeleMini stores only a single flight, so it will need to be downloaded and erased after each flight to capture data. This only affects on-board flight logging; the altimeter will still transmit telemetry and fire ejection charges at the proper times.
GPS Locked: For a TeleMetrum or TeleMega device, this indicates whether the GPS receiver is currently able to compute position information. GPS requires at least 4 satellites to compute an accurate position.
GPS Ready: For a TeleMetrum or TeleMega device, this indicates whether GPS has reported at least 10 consecutive positions without losing lock. This ensures that the GPS receiver has reliable reception from the satellites.
Apogee Igniter: This indicates whether the apogee igniter has continuity. If the igniter has a low resistance, then the voltage measured here will be close to the Li-Po battery voltage. A value greater than 3.2V is required for a GO status.
Main Igniter: This indicates whether the main igniter has continuity. If the igniter has a low resistance, then the voltage measured here will be close to the Li-Po battery voltage. A value greater than 3.2V is required for a GO status.
Igniter A-D: This indicates whether the indicated additional pyro channel igniter has continuity. If the igniter has a low resistance, then the voltage measured here will be close to the Li-Po battery voltage. A value greater than 3.2V is required for a GO status.

The Pad tab also shows the location of the Android device.

12.8. Flight¶

The Flight tab shows information used to evaluate and spot a rocket while in flight. It displays speed and height data to monitor the health of the rocket, along with elevation, range and bearing to help locate the rocket in the sky.

While the Flight tab is displayed, the voice announcements will include current speed, height, elevation and bearing information.

Speed: Shows current vertical speed. During descent, the speed values are averaged over a fairly long time to try and make them steadier.
Height: Shows the current height above the launch pad.
Max Speed: Shows the maximum vertical speed seen during the flight.
Max Height: Shows the maximum height above launch pad.
Elevation: This is the angle above the horizon from the android devices current position.
Range: The total distance from the android device to the rocket, including both ground distance and difference in altitude. Use this to gauge how large the rocket is likely to appear in the sky.
Bearing: This is the aziumuth from true north for the rocket from the android device. Use this in combination with the Elevation value to help locate the rocket in the sky, or at least to help point the antenna in the general direction. This is provided in both degrees and a compass point (like West South West). You’ll want to know which direction is true north before launching your rocket.
Ground Distance: This shows the distance across the ground to the lat/lon where the rocket is located. Use this to estimate what is currently under the rocket.
Latitude/Longitude: Displays the last known location of the rocket.
Apogee Igniter: This indicates whether the apogee igniter has continuity. If the igniter has a low resistance, then the voltage measured here will be close to the Li-Po battery voltage. A value greater than 3.2V is required for a GO status.
Main Igniter: This indicates whether the main igniter has continuity. If the igniter has a low resistance, then the voltage measured here will be close to the Li-Po battery voltage. A value greater than 3.2V is required for a GO status.

12.9. Recover¶

The Recover tab shows information used while recovering the rocket on the ground after flight.

While the Recover tab is displayed, the voice announcements will include distance along with either bearing or direction, depending on whether you are moving.

Bearing: This is the aziumuth from true north for the rocket from the android device. Use this in combination with the Elevation value to help locate the rocket in the sky, or at least to help point the antenna in the general direction. This is provided in both degrees and a compass point (like West South West). You’ll want to know which direction is true north before launching your rocket.
Direction: When you are in motion, this provides the angle from your current direction of motion towards the rocket.
Distance: Distance over the ground to the rocket.
Tar Lat/Tar Lon: Displays the last known location of the rocket.
My Lat/My Lon: Displays the location of the Android device.
Max Height: Shows the maximum height above launch pad.
Max Speed: Shows the maximum vertical speed seen during the flight.
Max Accel: Shows the maximum vertical acceleration seen during the flight.

12.10. Map¶

The Map tab shows a map of the area around the rocket being tracked along with information needed to recover it.

On the map itself, icons showing the location of the android device along with the last known location of each tracker. A blue line is drawn from the android device location to the currently selected tracker.

Below the map, the distance and either bearing or direction along with the lat/lon of the target and the android device are shown

The Map tab provides the same voice announcements as the Recover tab.

12.11. Downloading Flight Logs¶

AltosDroid always saves every bit of telemetry data it receives. To download that to a computer for use with AltosUI, remove the SD card from your Android device, or connect your device to your computer’s USB port and browse the files on that device. You will find .telem files in the TeleMetrum directory that will work with AltosUI directly.