+ </itemizedlist>
+ <para>
+ Finally, the largest portion of the window contains a set of
+ tabs, each of which contain some information about the rocket.
+ They're arranged in 'flight order' so that as the flight
+ progresses, the selected tab automatically switches to display
+ data relevant to the current state of the flight. You can select
+ other tabs at any time. The final 'table' tab displays all of
+ the raw telemetry values in one place in a spreadsheet-like format.
+ </para>
+ <section>
+ <title>Launch Pad</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="launch-pad.png" width="5.5in"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ The 'Launch 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:
+ <variablelist>
+ <varlistentry>
+ <term>Battery Voltage</term>
+ <listitem>
+ <para>
+ This indicates whether the Li-Po battery powering the
+ flight computer has sufficient charge to last for
+ the duration of the flight. A value of more than
+ 3.8V is required for a 'GO' status.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Apogee Igniter Voltage</term>
+ <listitem>
+ <para>
+ 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.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Main Igniter Voltage</term>
+ <listitem>
+ <para>
+ 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.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>On-board Data Logging</term>
+ <listitem>
+ <para>
+ 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. Most of our flight computers can store multiple
+ flights, depending on the configured maximum flight log
+ size. TeleMini v1.0 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 even if the flight
+ data storage is full.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>GPS Locked</term>
+ <listitem>
+ <para>
+ 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.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>GPS Ready</term>
+ <listitem>
+ <para>
+ 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.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+ <para>
+ The Launchpad tab also shows the computed launch pad position
+ and altitude, averaging many reported positions to improve the
+ accuracy of the fix.
+ </para>
+ </section>
+ <section>
+ <title>Ascent</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="ascent.png" width="5.5in"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ This tab is shown during Boost, Fast and Coast
+ phases. The information displayed here helps monitor the
+ rocket as it heads towards apogee.
+ </para>
+ <para>
+ The height, speed, acceleration and tilt are shown along
+ with the maximum values for each of them. This allows you to
+ quickly answer the most commonly asked questions you'll hear
+ during flight.
+ </para>
+ <para>
+ The current latitude and longitude reported by the GPS are
+ also shown. Note that under high acceleration, these values
+ may not get updated as the GPS receiver loses position
+ fix. Once the rocket starts coasting, the receiver should
+ start reporting position again.
+ </para>
+ <para>
+ Finally, the current igniter voltages are reported as in the
+ Launch Pad tab. This can help diagnose deployment failures
+ caused by wiring which comes loose under high acceleration.
+ </para>
+ </section>
+ <section>
+ <title>Descent</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="descent.png" width="5.5in"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ Once the rocket has reached apogee and (we hope) activated the
+ apogee charge, attention switches to tracking the rocket on
+ the way back to the ground, and for dual-deploy flights,
+ waiting for the main charge to fire.
+ </para>
+ <para>
+ To monitor whether the apogee charge operated correctly, the
+ current descent rate is reported along with the current
+ height. Good descent rates vary based on the choice of recovery
+ components, but generally range from 15-30m/s on drogue and should
+ be below 10m/s when under the main parachute in a dual-deploy flight.
+ </para>
+ <para>
+ With GPS-equipped flight computers, you can locate the rocket in the
+ sky using the elevation and bearing information to figure
+ out where to look. Elevation is in degrees above the
+ horizon. Bearing is reported in degrees relative to true
+ north. Range can help figure out how big the rocket will
+ appear. Ground Distance shows how far it is to a point
+ directly under the rocket and can help figure out where the
+ rocket is likely to land. Note that all of these values are
+ relative to the pad location. If the elevation is near 90°,
+ the rocket is over the pad, not over you.
+ </para>
+ <para>
+ Finally, the igniter voltages are reported in this tab as
+ well, both to monitor the main charge as well as to see what
+ the status of the apogee charge is. Note that some commercial
+ e-matches are designed to retain continuity even after being
+ fired, and will continue to show as green or return from red to
+ green after firing.
+ </para>
+ </section>
+ <section>
+ <title>Landed</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="landed.png" width="5.5in"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ Once the rocket is on the ground, attention switches to
+ recovery. While the radio signal is often lost once the
+ rocket is on the ground, the last reported GPS position is
+ generally within a short distance of the actual landing location.
+ </para>
+ <para>
+ The last reported GPS position is reported both by
+ latitude and longitude as well as a bearing and distance from
+ the launch pad. The distance should give you a good idea of
+ whether to walk or hitch a ride. Take the reported
+ latitude and longitude and enter them into your hand-held GPS
+ unit and have that compute a track to the landing location.
+ </para>
+ <para>
+ Our flight computers will continue to transmit RDF
+ tones after landing, allowing you to locate the rocket by
+ following the radio signal if necessary. You may need to get
+ away from the clutter of the flight line, or even get up on
+ a hill (or your neighbor's RV roof) to receive the RDF signal.
+ </para>
+ <para>
+ The maximum height, speed and acceleration reported
+ during the flight are displayed for your admiring observers.
+ The accuracy of these immediate values depends on the quality
+ of your radio link and how many packets were received.
+ Recovering the on-board data after flight may yield
+ more precise results.
+ </para>
+ <para>
+ To get more detailed information about the flight, you can
+ click on the 'Graph Flight' button which will bring up a
+ graph window for the current flight.
+ </para>
+ </section>
+ <section>
+ <title>Table</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="table.png" width="5.5in"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ The table view shows all of the data available from the
+ flight computer. Probably the most useful data on
+ this tab is the detailed GPS information, which includes
+ horizontal dilution of precision information, and
+ information about the signal being received from the satellites.
+ </para>
+ </section>
+ <section>
+ <title>Site Map</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="site-map.png" width="5.5in"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ When the TeleMetrum has a GPS fix, the Site Map tab will map
+ the rocket's position to make it easier for you to locate the
+ rocket, both while it is in the air, and when it has landed. The
+ rocket's state is indicated by color: white for pad, red for
+ boost, pink for fast, yellow for coast, light blue for drogue,
+ dark blue for main, and black for landed.
+ </para>
+ <para>
+ The map's scale is approximately 3m (10ft) per pixel. The map
+ can be dragged using the left mouse button. The map will attempt
+ to keep the rocket roughly centered while data is being received.
+ </para>
+ <para>
+ Images are fetched automatically via the Google Maps Static API,
+ and cached on disk for reuse. If map images cannot be downloaded,
+ the rocket's path will be traced on a dark gray background
+ instead.
+ </para>
+ <para>
+ You can pre-load images for your favorite launch sites
+ before you leave home; check out the 'Preload Maps' section below.
+ </para>
+ </section>
+ </section>
+ <section>
+ <title>Save Flight Data</title>
+ <para>
+ The altimeter records flight data to its internal flash memory.
+ TeleMetrum data is recorded at a much higher rate than the telemetry
+ system can handle, and is not subject to radio drop-outs. As
+ such, it provides a more complete and precise record of the
+ flight. The 'Save Flight Data' button allows you to read the
+ flash memory and write it to disk.
+ </para>
+ <para>
+ Clicking on the 'Save Flight Data' button brings up a list of
+ connected flight computers and TeleDongle devices. If you select a
+ flight computer, the flight data will be downloaded from that
+ device directly. If you select a TeleDongle device, flight data
+ will be downloaded from a flight computer over radio link via the
+ specified TeleDongle. See the chapter on Controlling An Altimeter
+ Over The Radio Link for more information.
+ </para>
+ <para>
+ After the device has been selected, a dialog showing the
+ flight data saved in the device will be shown allowing you to
+ select which flights to download and which to delete. With
+ version 0.9 or newer firmware, you must erase flights in order
+ for the space they consume to be reused by another
+ flight. This prevents accidentally losing flight data
+ if you neglect to download data before flying again. Note that
+ if there is no more space available in the device, then no
+ data will be recorded during the next flight.
+ </para>
+ <para>
+ The file name for each flight log is computed automatically
+ from the recorded flight date, altimeter serial number and
+ flight number information.
+ </para>
+ </section>
+ <section>
+ <title>Replay Flight</title>
+ <para>
+ Select this button and you are prompted to select a flight
+ record file, either a .telem file recording telemetry data or a
+ .eeprom file containing flight data saved from the altimeter
+ flash memory.
+ </para>
+ <para>
+ Once a flight record is selected, the flight monitor interface
+ is displayed and the flight is re-enacted in real time. Check
+ the Monitor Flight chapter above to learn how this window operates.
+ </para>
+ </section>
+ <section>
+ <title>Graph Data</title>
+ <para>
+ Select this button and you are prompted to select a flight
+ record file, either a .telem file recording telemetry data or a
+ .eeprom file containing flight data saved from
+ flash memory.
+ </para>
+ <para>
+ Note that telemetry files will generally produce poor graphs
+ due to the lower sampling rate and missed telemetry packets.
+ Use saved flight data in .eeprom files for graphing where possible.
+ </para>
+ <para>
+ Once a flight record is selected, a window with multiple tabs is
+ opened.
+ </para>
+ <section>
+ <title>Flight Graph</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="graph.png" width="6in" scalefit="1"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ By default, the graph contains acceleration (blue),
+ velocity (green) and altitude (red).
+ </para>
+ <para>
+ The graph can be zoomed into a particular area by clicking and
+ dragging down and to the right. Once zoomed, the graph can be
+ reset by clicking and dragging up and to the left. Holding down
+ control and clicking and dragging allows the graph to be panned.
+ The right mouse button causes a pop-up menu to be displayed, giving
+ you the option save or print the plot.
+ </para>
+ </section>
+ <section>
+ <title>Configure Graph</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="graph-configure.png" width="6in" scalefit="1"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ This selects which graph elements to show, and, at the
+ very bottom, lets you switch between metric and
+ imperial units
+ </para>
+ </section>
+ <section>
+ <title>Flight Statistics</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="graph-stats.png" width="6in" scalefit="1"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ Shows overall data computed from the flight.
+ </para>
+ </section>
+ <section>
+ <title>Map</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="graph-map.png" width="6in" scalefit="1"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ Shows a satellite image of the flight area overlaid
+ with the path of the flight. The red concentric
+ circles mark the launch pad, the black concentric
+ circles mark the landing location.
+ </para>
+ </section>
+ </section>
+ <section>
+ <title>Export Data</title>
+ <para>
+ This tool takes the raw data files and makes them available for
+ external analysis. When you select this button, you are prompted to
+ select a flight data file, which can be either a .eeprom or .telem.
+ The .eeprom files contain higher resolution and more continuous data,
+ while .telem files contain receiver signal strength information.
+ Next, a second dialog appears which is used to select
+ where to write the resulting file. It has a selector to choose
+ between CSV and KML file formats.
+ </para>
+ <section>
+ <title>Comma Separated Value Format</title>
+ <para>
+ This is a text file containing the data in a form suitable for
+ import into a spreadsheet or other external data analysis
+ tool. The first few lines of the file contain the version and
+ configuration information from the altimeter, then
+ there is a single header line which labels all of the
+ fields. All of these lines start with a '#' character which
+ many tools can be configured to skip over.
+ </para>
+ <para>
+ The remaining lines of the file contain the data, with each
+ field separated by a comma and at least one space. All of
+ the sensor values are converted to standard units, with the
+ barometric data reported in both pressure, altitude and
+ height above pad units.
+ </para>
+ </section>
+ <section>
+ <title>Keyhole Markup Language (for Google Earth)</title>
+ <para>
+ This is the format used by Google Earth to provide an overlay
+ within that application. With this, you can use Google Earth to
+ see the whole flight path in 3D.
+ </para>
+ </section>
+ </section>
+ <section>
+ <title>Configure Altimeter</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="configure-altimeter.png" width="3.6in" scalefit="1"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ Select this button and then select either an altimeter or
+ TeleDongle Device from the list provided. Selecting a TeleDongle
+ device will use the radio link to configure a remote altimeter.
+ </para>
+ <para>
+ The first few lines of the dialog provide information about the
+ connected device, including the product name,
+ software version and hardware serial number. Below that are the
+ individual configuration entries.
+ </para>
+ <para>
+ At the bottom of the dialog, there are four buttons:
+ </para>
+ <variablelist>
+ <varlistentry>
+ <term>Save</term>
+ <listitem>
+ <para>
+ This writes any changes to the
+ configuration parameter block in flash memory. If you don't
+ press this button, any changes you make will be lost.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Reset</term>
+ <listitem>
+ <para>
+ This resets the dialog to the most recently saved values,
+ erasing any changes you have made.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Reboot</term>
+ <listitem>
+ <para>
+ This reboots the device. Use this to
+ switch from idle to pad mode by rebooting once the rocket is
+ oriented for flight, or to confirm changes you think you saved
+ are really saved.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Close</term>
+ <listitem>
+ <para>
+ This closes the dialog. Any unsaved changes will be
+ lost.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ <para>
+ The rest of the dialog contains the parameters to be configured.
+ </para>
+ <section>
+ <title>Main Deploy Altitude</title>
+ <para>
+ This sets the altitude (above the recorded pad altitude) at
+ which the 'main' igniter will fire. The drop-down menu shows
+ some common values, but you can edit the text directly and
+ choose whatever you like. If the apogee charge fires below
+ this altitude, then the main charge will fire two seconds
+ after the apogee charge fires.
+ </para>
+ </section>
+ <section>
+ <title>Apogee Delay</title>
+ <para>
+ When flying redundant electronics, it's often important to
+ ensure that multiple apogee charges don't fire at precisely
+ the same time, as that can over pressurize the apogee deployment
+ bay and cause a structural failure of the air-frame. The Apogee
+ Delay parameter tells the flight computer to fire the apogee
+ charge a certain number of seconds after apogee has been
+ detected.
+ </para>
+ </section>
+ <section>
+ <title>Radio Frequency</title>
+ <para>
+ This configures which of the frequencies to use for both
+ telemetry and packet command mode. Note that if you set this
+ value via packet command mode, the TeleDongle frequency will
+ also be automatically reconfigured to match so that
+ communication will continue afterwards.
+ </para>
+ </section>
+ <section>
+ <title>RF Calibration</title>
+ <para>
+ The radios in every Altus Metrum device are calibrated at the
+ factory to ensure that they transmit and receive on the
+ specified frequency. If you need to you can adjust the calibration
+ by changing this value. Do not do this without understanding what
+ the value means, read the appendix on calibration and/or the source
+ code for more information. To change a TeleDongle's calibration,
+ you must reprogram the unit completely.
+ </para>
+ </section>
+ <section>
+ <title>Telemetry/RDF/APRS Enable</title>
+ <para>
+ Enables the radio for transmission during flight. When
+ disabled, the radio will not transmit anything during flight
+ at all.
+ </para>
+ </section>
+ <section>
+ <title>APRS Interval</title>
+ <para>
+ How often to transmit GPS information via APRS (in
+ seconds). When set to zero, APRS transmission is
+ disabled. This option is available on TeleMetrum v2 and
+ TeleMega boards. TeleMetrum v1 boards cannot transmit APRS
+ packets. Note that a single APRS packet takes nearly a full
+ second to transmit, so enabling this option will prevent
+ sending any other telemetry during that time.
+ </para>
+ </section>
+ <section>
+ <title>Callsign</title>
+ <para>
+ This sets the call sign included in each telemetry packet. Set this
+ as needed to conform to your local radio regulations.
+ </para>
+ </section>
+ <section>
+ <title>Maximum Flight Log Size</title>
+ <para>
+ This sets the space (in kilobytes) allocated for each flight
+ log. The available space will be divided into chunks of this
+ size. A smaller value will allow more flights to be stored,
+ a larger value will record data from longer flights.
+ </para>
+ </section>
+ <section>
+ <title>Ignite Mode</title>
+ <para>
+ TeleMetrum and TeleMini provide two igniter channels as they
+ were originally designed as dual-deploy flight
+ computers. This configuration parameter allows the two
+ channels to be used in different configurations.
+ </para>
+ <variablelist>
+ <varlistentry>
+ <term>Dual Deploy</term>
+ <listitem>
+ <para>
+ This is the usual mode of operation; the
+ 'apogee' channel is fired at apogee and the 'main'
+ channel at the height above ground specified by the
+ 'Main Deploy Altitude' during descent.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Redundant Apogee</term>
+ <listitem>
+ <para>
+ This fires both channels at
+ apogee, the 'apogee' channel first followed after a two second
+ delay by the 'main' channel.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Redundant Main</term>
+ <listitem>
+ <para>
+ This fires both channels at the
+ height above ground specified by the Main Deploy
+ Altitude setting during descent. The 'apogee'
+ channel is fired first, followed after a two second
+ delay by the 'main' channel.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </section>
+ <section>
+ <title>Pad Orientation</title>
+ <para>
+ Because they include accelerometers, TeleMetrum and
+ TeleMega are sensitive to the orientation of the board. By
+ default, they expect the antenna end to point forward. This
+ parameter allows that default to be changed, permitting the
+ board to be mounted with the antenna pointing aft instead.
+ </para>
+ <variablelist>
+ <varlistentry>
+ <term>Antenna Up</term>
+ <listitem>
+ <para>
+ In this mode, the antenna end of the
+ flight computer must point forward, in line with the
+ expected flight path.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Antenna Down</term>
+ <listitem>
+ <para>
+ In this mode, the antenna end of the
+ flight computer must point aft, in line with the
+ expected flight path.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </section>
+ <section>
+ <title>Configure Pyro Channels</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="configure-pyro.png" width="6in" scalefit="1"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ This opens a separate window to configure the additional
+ pyro channels available on TeleMega. One column is
+ presented for each channel. Each row represents a single
+ parameter, if enabled the parameter must meet the specified
+ test for the pyro channel to be fired. See the Pyro Channels
+ section in the System Operation chapter above for a
+ description of these parameters.
+ </para>
+ <para>
+ Select conditions and set the related value; the pyro
+ channel will be activated when <emphasis>all</emphasis> of the
+ conditions are met. Each pyro channel has a separate set of
+ configuration values, so you can use different values for
+ the same condition with different channels.
+ </para>
+ <para>
+ Once you have selected the appropriate configuration for all
+ of the necessary pyro channels, you can save the pyro
+ configuration along with the rest of the flight computer
+ configuration by pressing the 'Save' button in the main
+ Configure Flight Computer window.
+ </para>
+ </section>
+ </section>
+ <section>
+ <title>Configure AltosUI</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="configure-altosui.png" width="2.4in" scalefit="1"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ This button presents a dialog so that you can configure the AltosUI global settings.
+ </para>
+ <section>
+ <title>Voice Settings</title>
+ <para>
+ AltosUI provides voice announcements during flight so that you
+ can keep your eyes on the sky and still get information about
+ the current flight status. However, sometimes you don't want
+ to hear them.
+ </para>
+ <variablelist>
+ <varlistentry>
+ <term>Enable</term>
+ <listitem>
+ <para>Turns all voice announcements on and off</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Test Voice</term>
+ <listitem>
+ <para>
+ Plays a short message allowing you to verify
+ that the audio system is working and the volume settings
+ are reasonable
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </section>
+ <section>
+ <title>Log Directory</title>
+ <para>
+ AltosUI logs all telemetry data and saves all TeleMetrum flash
+ data to this directory. This directory is also used as the
+ staring point when selecting data files for display or export.
+ </para>
+ <para>
+ Click on the directory name to bring up a directory choosing
+ dialog, select a new directory and click 'Select Directory' to
+ change where AltosUI reads and writes data files.
+ </para>
+ </section>
+ <section>
+ <title>Callsign</title>
+ <para>
+ This value is transmitted in each command packet sent from
+ TeleDongle and received from an altimeter. It is not used in
+ telemetry mode, as the callsign configured in the altimeter board
+ is included in all telemetry packets. Configure this
+ with the AltosUI operators call sign as needed to comply with
+ your local radio regulations.
+ </para>
+ <para>
+ Note that to successfully command a flight computer over the radio
+ (to configure the altimeter, monitor idle, or fire pyro charges),
+ the callsign configured here must exactly match the callsign
+ configured in the flight computer. This matching is case
+ sensitive.
+ </para>
+ </section>
+ <section>
+ <title>Imperial Units</title>
+ <para>
+ This switches between metric units (meters) and imperial
+ units (feet and miles). This affects the display of values
+ use during flight monitoring, configuration, data graphing
+ and all of the voice announcements. It does not change the
+ units used when exporting to CSV files, those are always
+ produced in metric units.
+ </para>
+ </section>
+ <section>
+ <title>Font Size</title>
+ <para>
+ Selects the set of fonts used in the flight monitor
+ window. Choose between the small, medium and large sets.
+ </para>
+ </section>
+ <section>
+ <title>Serial Debug</title>
+ <para>
+ This causes all communication with a connected device to be
+ dumped to the console from which AltosUI was started. If
+ you've started it from an icon or menu entry, the output
+ will simply be discarded. This mode can be useful to debug
+ various serial communication issues.
+ </para>
+ </section>
+ <section>
+ <title>Manage Frequencies</title>
+ <para>
+ This brings up a dialog where you can configure the set of
+ frequencies shown in the various frequency menus. You can
+ add as many as you like, or even reconfigure the default
+ set. Changing this list does not affect the frequency
+ settings of any devices, it only changes the set of
+ frequencies shown in the menus.
+ </para>
+ </section>
+ </section>
+ <section>
+ <title>Configure Groundstation</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="configure-groundstation.png" width="3.1in" scalefit="1"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ Select this button and then select a TeleDongle Device from the list provided.
+ </para>
+ <para>
+ The first few lines of the dialog provide information about the
+ connected device, including the product name,
+ software version and hardware serial number. Below that are the
+ individual configuration entries.
+ </para>
+ <para>
+ Note that the TeleDongle itself doesn't save any configuration
+ data, the settings here are recorded on the local machine in
+ the Java preferences database. Moving the TeleDongle to
+ another machine, or using a different user account on the same
+ machine will cause settings made here to have no effect.
+ </para>
+ <para>
+ At the bottom of the dialog, there are three buttons:
+ </para>
+ <variablelist>
+ <varlistentry>
+ <term>Save</term>
+ <listitem>
+ <para>
+ This writes any changes to the
+ local Java preferences file. If you don't
+ press this button, any changes you make will be lost.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Reset</term>
+ <listitem>
+ <para>
+ This resets the dialog to the most recently saved values,
+ erasing any changes you have made.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Close</term>
+ <listitem>
+ <para>
+ This closes the dialog. Any unsaved changes will be
+ lost.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ <para>
+ The rest of the dialog contains the parameters to be configured.
+ </para>
+ <section>
+ <title>Frequency</title>
+ <para>
+ This configures the frequency to use for both telemetry and
+ packet command mode. Set this before starting any operation
+ involving packet command mode so that it will use the right
+ frequency. Telemetry monitoring mode also provides a menu to
+ change the frequency, and that menu also sets the same Java
+ preference value used here.
+ </para>
+ </section>
+ <section>
+ <title>Radio Calibration</title>
+ <para>
+ The radios in every Altus Metrum device are calibrated at the
+ factory to ensure that they transmit and receive on the
+ specified frequency. To change a TeleDongle's calibration,
+ you must reprogram the unit completely, so this entry simply
+ shows the current value and doesn't allow any changes.
+ </para>
+ </section>
+ </section>
+ <section>
+ <title>Flash Image</title>
+ <para>
+ This reprograms Altus Metrum devices with new
+ firmware. TeleMetrum v1.x, TeleDongle, TeleMini and TeleBT are
+ all reprogrammed by using another similar unit as a
+ programming dongle (pair programming). TeleMega, TeleMetrum v2
+ and EasyMini are all programmed directly over their USB ports
+ (self programming). Please read the directions for flashing
+ devices in the Updating Device Firmware chapter below.
+ </para>
+ </section>
+ <section>
+ <title>Fire Igniter</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="fire-igniter.png" width="1.2in" scalefit="1"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ This activates the igniter circuits in the flight computer to help
+ test recovery systems deployment. Because this command can operate
+ over the Packet Command Link, you can prepare the rocket as
+ for flight and then test the recovery system without needing
+ to snake wires inside the air-frame.
+ </para>
+ <para>
+ Selecting the 'Fire Igniter' button brings up the usual device
+ selection dialog. Pick the desired device. This brings up another
+ window which shows the current continuity test status for all
+ of the pyro channels.
+ </para>
+ <para>
+ Next, select the desired igniter to fire. This will enable the
+ 'Arm' button.
+ </para>
+ <para>
+ Select the 'Arm' button. This enables the 'Fire' button. The
+ word 'Arm' is replaced by a countdown timer indicating that
+ you have 10 seconds to press the 'Fire' button or the system
+ will deactivate, at which point you start over again at
+ selecting the desired igniter.
+ </para>
+ </section>
+ <section>
+ <title>Scan Channels</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="scan-channels.png" width="3.2in" scalefit="1"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ This listens for telemetry packets on all of the configured
+ frequencies, displaying information about each device it
+ receives a packet from. You can select which of the three
+ telemetry formats should be tried; by default, it only listens
+ for the standard telemetry packets used in v1.0 and later
+ firmware.
+ </para>
+ </section>
+ <section>
+ <title>Load Maps</title>
+ <informalfigure>
+ <mediaobject>
+ <imageobject>
+ <imagedata fileref="load-maps.png" width="5.2in" scalefit="1"/>
+ </imageobject>
+ </mediaobject>
+ </informalfigure>
+ <para>
+ Before heading out to a new launch site, you can use this to
+ load satellite images in case you don't have internet
+ connectivity at the site. This loads a fairly large area
+ around the launch site, which should cover any flight you're likely to make.
+ </para>
+ <para>
+ There's a drop-down menu of launch sites we know about; if
+ your favorites aren't there, please let us know the lat/lon
+ and name of the site. The contents of this list are actually
+ downloaded from our server at run-time, so as new sites are sent
+ in, they'll get automatically added to this list.
+ </para>
+ <para>
+ If the launch site isn't in the list, you can manually enter the lat/lon values
+ </para>
+ <para>
+ Clicking the 'Load Map' button will fetch images from Google
+ Maps; note that Google limits how many images you can fetch at
+ once, so if you load more than one launch site, you may get
+ some gray areas in the map which indicate that Google is tired
+ of sending data to you. Try again later.
+ </para>
+ </section>
+ <section>
+ <title>Monitor Idle</title>
+ <para>
+ This brings up a dialog similar to the Monitor Flight UI,
+ except it works with the altimeter in “idle” mode by sending
+ query commands to discover the current state rather than
+ listening for telemetry packets. Because this uses command
+ mode, it needs to have the TeleDongle and flight computer
+ callsigns match exactly. If you can receive telemetry, but
+ cannot manage to run Monitor Idle, then it's very likely that
+ your callsigns are different in some way.
+ </para>
+ </section>
+ </chapter>
+ <chapter>
+ <title>AltosDroid</title>
+ <para>
+ AltosDroid provides the same flight monitoring capabilities as
+ AltosUI, but runs on Android devices and is designed to connect
+ to a TeleBT receiver over Bluetooth™. AltosDroid monitors
+ telemetry data, logging it to internal storage in the Android
+ device, and presents that data in a UI the same way the 'Monitor
+ Flight' window does in AltosUI.
+ </para>
+ <para>
+ This manual will explain how to configure AltosDroid, connect
+ to TeleBT, operate the flight monitoring interface and describe
+ what the displayed data means.
+ </para>
+ <section>
+ <title>Installing AltosDroid</title>
+ <para>
+ 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.
+ </para>
+ </section>
+ <section>
+ <title>Connecting to TeleBT</title>
+ <para>
+ 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'.
+ </para>
+ <para>
+ Subsequent connections will not require you to enter that
+ code, and your 'paired' device will appear in the list without
+ scanning.
+ </para>
+ </section>
+ <section>
+ <title>Configuring AltosDroid</title>
+ <para>
+ The only configuration option available for AltosDroid is
+ which frequency to listen on. Press the Android 'Menu' button
+ or soft-key and pick the 'Select radio frequency' entry. That
+ brings up a menu of pre-set radio frequencies; pick the one
+ which matches your altimeter.
+ </para>
+ </section>
+ <section>
+ <title>AltosDroid Flight Monitoring</title>
+ <para>
+ 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.
+ </para>
+ <section>
+ <title>Pad</title>
+ <para>
+ The 'Launch 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:
+ <variablelist>
+ <varlistentry>
+ <term>Battery Voltage</term>
+ <listitem>
+ <para>
+ This indicates whether the Li-Po battery
+ powering the TeleMetrum has sufficient charge to last for
+ the duration of the flight. A value of more than
+ 3.8V is required for a 'GO' status.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Apogee Igniter Voltage</term>
+ <listitem>
+ <para>
+ 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.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>Main Igniter Voltage</term>
+ <listitem>
+ <para>
+ 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.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>On-board Data Logging</term>
+ <listitem>
+ <para>
+ 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 can store multiple flights, depending
+ on the configured maximum flight log size. 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.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>GPS Locked</term>
+ <listitem>
+ <para>
+ 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.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term>GPS Ready</term>
+ <listitem>
+ <para>
+ 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.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+ <para>
+ The Launchpad tab also shows the computed launch pad position
+ and altitude, averaging many reported positions to improve the
+ accuracy of the fix.
+ </para>
+ </section>
+ </section>
+ <section>
+ <title>Downloading Flight Logs</title>
+ <para>
+ AltosDroid always saves every bit of telemetry data it
+ receives. To download that to a computer for use with AltosUI,
+ simply 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.
+ </para>
+ </section>
+ </chapter>
+ <chapter>
+ <title>Using Altus Metrum Products</title>
+ <section>
+ <title>Being Legal</title>
+ <para>
+ First off, in the US, you need an <ulink url="http://www.altusmetrum.org/Radio/">amateur radio license</ulink> or
+ other authorization to legally operate the radio transmitters that are part
+ of our products.
+ </para>
+ </section>
+ <section>
+ <title>In the Rocket</title>
+ <para>
+ In the rocket itself, you just need a flight computer and
+ a single-cell, 3.7 volt nominal Li-Po rechargeable battery. An
+ 850mAh battery weighs less than a 9V alkaline battery, and will
+ run a TeleMetrum or TeleMega for hours.
+ A 110mAh battery weighs less than a triple A battery and is a good
+ choice for use with TeleMini.
+ </para>
+ <para>
+ By default, we ship flight computers with a simple wire antenna.
+ If your electronics bay or the air-frame it resides within is made
+ of carbon fiber, which is opaque to RF signals, you may prefer to
+ install an SMA connector so that you can run a coaxial cable to an
+ antenna mounted elsewhere in the rocket. However, note that the
+ GPS antenna is fixed on all current products, so you really want
+ to install the flight computer in a bay made of RF-transparent
+ materials if at all possible.
+ </para>
+ </section>
+ <section>
+ <title>On the Ground</title>
+ <para>
+ To receive the data stream from the rocket, you need an antenna and short
+ feed-line connected to one of our <ulink url="http://www.altusmetrum.org/TeleDongle/">TeleDongle</ulink> units. If possible, use an SMA to BNC
+ adapter instead of feedline between the antenna feedpoint and
+ TeleDongle, as this will give you the best performance. The
+ TeleDongle in turn plugs directly into the USB port on a notebook
+ computer. Because TeleDongle looks like a simple serial port, your computer
+ does not require special device drivers... just plug it in.
+ </para>
+ <para>
+ The GUI tool, AltosUI, is written in Java and runs across
+ Linux, Mac OS and Windows. There's also a suite of C tools
+ for Linux which can perform most of the same tasks.
+ </para>
+ <para>
+ Alternatively, a TeleBT attached with an SMA to BNC adapter at the
+ feed point of a hand-held yagi used in conjunction with an Android
+ device running AltosDroid makes an outstanding ground station.
+ </para>
+ <para>
+ After the flight, you can use the radio link to extract the more detailed data
+ logged in either TeleMetrum or TeleMini devices, or you can use a mini USB cable to plug into the
+ TeleMetrum board directly. Pulling out the data without having to open up
+ the rocket is pretty cool! A USB cable is also how you charge the Li-Po
+ battery, so you'll want one of those anyway... the same cable used by lots
+ of digital cameras and other modern electronic stuff will work fine.
+ </para>
+ <para>
+ If your rocket lands out of sight, you may enjoy having a hand-held
+ GPS receiver, so that you can put in a way-point for the last
+ reported rocket position before touch-down. This makes looking for
+ your rocket a lot like Geo-Caching... just go to the way-point and
+ look around starting from there. AltosDroid on an Android device
+ with GPS receiver works great for this, too!
+ </para>
+ <para>
+ You may also enjoy having a ham radio “HT” that covers the 70cm band... you
+ can use that with your antenna to direction-find the rocket on the ground
+ the same way you can use a Walston or Beeline tracker. This can be handy
+ if the rocket is hiding in sage brush or a tree, or if the last GPS position
+ doesn't get you close enough because the rocket dropped into a canyon, or
+ the wind is blowing it across a dry lake bed, or something like that... Keith
+ currently uses a Yaesu VX-7R, Bdale has a Baofung UV-5R
+ which isn't as nice, but was a whole lot cheaper.
+ </para>
+ <para>
+ So, to recap, on the ground the hardware you'll need includes:
+ <orderedlist inheritnum='inherit' numeration='arabic'>
+ <listitem>
+ <para>
+ an antenna and feed-line or adapter
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ a TeleDongle
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ a notebook computer
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ optionally, a hand-held GPS receiver
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ optionally, an HT or receiver covering 435 MHz
+ </para>
+ </listitem>
+ </orderedlist>
+ </para>
+ <para>
+ The best hand-held commercial directional antennas we've found for radio
+ direction finding rockets are from
+ <ulink url="http://www.arrowantennas.com/" >
+ Arrow Antennas.
+ </ulink>
+ The 440-3 and 440-5 are both good choices for finding a
+ TeleMetrum- or TeleMini- equipped rocket when used with a suitable
+ 70cm HT. TeleDongle and an SMA to BNC adapter fit perfectly
+ between the driven element and reflector of Arrow antennas.
+ </para>
+ </section>
+ <section>
+ <title>Data Analysis</title>
+ <para>
+ Our software makes it easy to log the data from each flight, both the
+ telemetry received during the flight itself, and the more
+ complete data log recorded in the flash memory on the altimeter
+ board. Once this data is on your computer, our post-flight tools make it
+ easy to quickly get to the numbers everyone wants, like apogee altitude,
+ max acceleration, and max velocity. You can also generate and view a
+ standard set of plots showing the altitude, acceleration, and
+ velocity of the rocket during flight. And you can even export a TeleMetrum data file
+ usable with Google Maps and Google Earth for visualizing the flight path
+ in two or three dimensions!
+ </para>
+ <para>
+ Our ultimate goal is to emit a set of files for each flight that can be
+ published as a web page per flight, or just viewed on your local disk with
+ a web browser.
+ </para>
+ </section>
+ <section>
+ <title>Future Plans</title>
+ <para>
+ We've designed a simple GPS based radio tracker called TeleGPS.
+ If all goes well, we hope to introduce this in the first
+ half of 2014.
+ </para>
+ <para>
+ We have designed and prototyped several “companion boards” that
+ can attach to the companion connector on TeleMetrum and TeleMega
+ flight computers to collect more data, provide more pyro channels,
+ and so forth. We do not yet know if or when any of these boards
+ will be produced in enough quantity to sell. If you have specific
+ interests for data collection or control of events in your rockets
+ beyond the capabilities of our existing productions, please let
+ us know!
+ </para>
+ <para>
+ Because all of our work is open, both the hardware designs and the
+ software, if you have some great idea for an addition to the current
+ Altus Metrum family, feel free to dive in and help! Or let us know
+ what you'd like to see that we aren't already working on, and maybe
+ we'll get excited about it too...
+ </para>
+ <para>
+ Watch our
+ <ulink url="http://altusmetrum.org/">web site</ulink> for more news
+ and information as our family of products evolves!
+ </para>
+ </section>
+ </chapter>
+ <chapter>
+ <title>Altimeter Installation Recommendations</title>
+ <para>
+ Building high-power rockets that fly safely is hard enough. Mix
+ in some sophisticated electronics and a bunch of radio energy
+ and some creativity and/or compromise may be required. This chapter
+ contains some suggestions about how to install Altus Metrum
+ products into a rocket air-frame, including how to safely and
+ reliably mix a variety of electronics into the same air-frame.
+ </para>
+ <section>
+ <title>Mounting the Altimeter</title>
+ <para>
+ The first consideration is to ensure that the altimeter is
+ securely fastened to the air-frame. For most of our products, we
+ prefer nylon standoffs and nylon screws; they're good to at least 50G
+ and cannot cause any electrical issues on the board. Metal screws
+ and standoffs are fine, too, just be careful to avoid electrical
+ shorts! For TeleMini v1.0, we usually cut small pieces of 1/16 inch
+ balsa to fit
+ under the screw holes, and then take 2x56 nylon screws and
+ screw them through the TeleMini mounting holes, through the
+ balsa and into the underlying material.
+ </para>
+ <orderedlist inheritnum='inherit' numeration='arabic'>
+ <listitem>
+ <para>
+ Make sure accelerometer-equipped products like TeleMetrum and
+ TeleMega are aligned precisely along the axis of
+ acceleration so that the accelerometer can accurately
+ capture data during the flight.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Watch for any metal touching components on the
+ board. Shorting out connections on the bottom of the board
+ can cause the altimeter to fail during flight.
+ </para>
+ </listitem>
+ </orderedlist>
+ </section>
+ <section>
+ <title>Dealing with the Antenna</title>
+ <para>
+ The antenna supplied is just a piece of solid, insulated,
+ wire. If it gets damaged or broken, it can be easily
+ replaced. It should be kept straight and not cut; bending or
+ cutting it will change the resonant frequency and/or
+ impedance, making it a less efficient radiator and thus
+ reducing the range of the telemetry signal.
+ </para>
+ <para>
+ Keeping metal away from the antenna will provide better range
+ and a more even radiation pattern. In most rockets, it's not
+ entirely possible to isolate the antenna from metal
+ components; there are often bolts, all-thread and wires from other
+ electronics to contend with. Just be aware that the more stuff
+ like this around the antenna, the lower the range.
+ </para>
+ <para>
+ Make sure the antenna is not inside a tube made or covered
+ with conducting material. Carbon fiber is the most common
+ culprit here -- CF is a good conductor and will effectively
+ shield the antenna, dramatically reducing signal strength and
+ range. Metallic flake paint is another effective shielding
+ material which should be avoided around any antennas.
+ </para>
+ <para>
+ If the ebay is large enough, it can be convenient to simply
+ mount the altimeter at one end and stretch the antenna out
+ inside. Taping the antenna to the sled can keep it straight
+ under acceleration. If there are metal rods, keep the
+ antenna as far away as possible.
+ </para>
+ <para>
+ For a shorter ebay, it's quite practical to have the antenna
+ run through a bulkhead and into an adjacent bay. Drill a small
+ hole in the bulkhead, pass the antenna wire through it and
+ then seal it up with glue or clay. We've also used acrylic
+ tubing to create a cavity for the antenna wire. This works a
+ bit better in that the antenna is known to stay straight and
+ not get folded by recovery components in the bay. Angle the
+ tubing towards the side wall of the rocket and it ends up
+ consuming very little space.
+ </para>
+ <para>
+ If you need to place the UHF antenna at a distance from the
+ altimeter, you can replace the antenna with an edge-mounted
+ SMA connector, and then run 50Ω coax from the board to the
+ antenna. Building a remote antenna is beyond the scope of this
+ manual.
+ </para>
+ </section>
+ <section>
+ <title>Preserving GPS Reception</title>
+ <para>
+ The GPS antenna and receiver used in TeleMetrum and TeleMega is
+ highly sensitive and normally have no trouble tracking enough
+ satellites to provide accurate position information for
+ recovering the rocket. However, there are many ways the GPS signal
+ can end up attenuated, negatively affecting GPS performance.
+ <orderedlist inheritnum='inherit' numeration='arabic'>
+ <listitem>
+ <para>
+ Conductive tubing or coatings. Carbon fiber and metal
+ tubing, or metallic paint will all dramatically attenuate the
+ GPS signal. We've never heard of anyone successfully
+ receiving GPS from inside these materials.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Metal components near the GPS patch antenna. These will
+ de-tune the patch antenna, changing the resonant frequency
+ away from the L1 carrier and reduce the effectiveness of the
+ antenna. You can place as much stuff as you like beneath the
+ antenna as that's covered with a ground plane. But, keep
+ wires and metal out from above the patch antenna.
+ </para>
+ </listitem>
+ </orderedlist>
+ </para>
+ </section>
+ <section>
+ <title>Radio Frequency Interference</title>
+ <para>
+ Any altimeter will generate RFI; the digital circuits use
+ high-frequency clocks that spray radio interference across a
+ wide band. Altus Metrum altimeters generate intentional radio
+ signals as well, increasing the amount of RF energy around the board.
+ </para>
+ <para>
+ Rocketry altimeters also use precise sensors measuring air
+ pressure and acceleration. Tiny changes in voltage can cause
+ these sensor readings to vary by a huge amount. When the
+ sensors start mis-reporting data, the altimeter can either
+ fire the igniters at the wrong time, or not fire them at all.
+ </para>
+ <para>
+ Voltages are induced when radio frequency energy is
+ transmitted from one circuit to another. Here are things that
+ influence the induced voltage and current:
+ </para>
+ <itemizedlist>
+ <listitem>
+ <para>
+ Keep wires from different circuits apart. Moving circuits
+ further apart will reduce RFI.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Avoid parallel wires from different circuits. The longer two
+ wires run parallel to one another, the larger the amount of
+ transferred energy. Cross wires at right angles to reduce
+ RFI.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Twist wires from the same circuits. Two wires the same
+ distance from the transmitter will get the same amount of
+ induced energy which will then cancel out. Any time you have
+ a wire pair running together, twist the pair together to
+ even out distances and reduce RFI. For altimeters, this
+ includes battery leads, switch hookups and igniter
+ circuits.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Avoid resonant lengths. Know what frequencies are present
+ in the environment and avoid having wire lengths near a
+ natural resonant length. Altus Metrum products transmit on the
+ 70cm amateur band, so you should avoid lengths that are a
+ simple ratio of that length; essentially any multiple of ¼
+ of the wavelength (17.5cm).
+ </para>
+ </listitem>
+ </itemizedlist>
+ </section>
+ <section>
+ <title>The Barometric Sensor</title>
+ <para>
+ Altusmetrum altimeters measure altitude with a barometric
+ sensor, essentially measuring the amount of air above the
+ rocket to figure out how high it is. A large number of
+ measurements are taken as the altimeter initializes itself to
+ figure out the pad altitude. Subsequent measurements are then
+ used to compute the height above the pad.
+ </para>
+ <para>
+ To accurately measure atmospheric pressure, the ebay
+ containing the altimeter must be vented outside the
+ air-frame. The vent must be placed in a region of linear
+ airflow, have smooth edges, and away from areas of increasing or
+ decreasing pressure.
+ </para>
+ <para>
+ All barometric sensors are quite sensitive to chemical damage from
+ the products of APCP or BP combustion, so make sure the ebay is
+ carefully sealed from any compartment which contains ejection
+ charges or motors.
+ </para>
+ </section>
+ <section>
+ <title>Ground Testing</title>
+ <para>
+ The most important aspect of any installation is careful
+ ground testing. Bringing an air-frame up to the LCO table which
+ hasn't been ground tested can lead to delays or ejection
+ charges firing on the pad, or, even worse, a recovery system
+ failure.
+ </para>
+ <para>
+ Do a 'full systems' test that includes wiring up all igniters
+ without any BP and turning on all of the electronics in flight
+ mode. This will catch any mistakes in wiring and any residual
+ RFI issues that might accidentally fire igniters at the wrong
+ time. Let the air-frame sit for several minutes, checking for
+ adequate telemetry signal strength and GPS lock. If any igniters
+ fire unexpectedly, find and resolve the issue before loading any
+ BP charges!
+ </para>
+ <para>
+ Ground test the ejection charges. Prepare the rocket for
+ flight, loading ejection charges and igniters. Completely
+ assemble the air-frame and then use the 'Fire Igniters'
+ interface through a TeleDongle to command each charge to
+ fire. Make sure the charge is sufficient to robustly separate
+ the air-frame and deploy the recovery system.
+ </para>
+ </section>
+ </chapter>
+ <chapter>
+ <title>Updating Device Firmware</title>
+ <para>
+ TeleMega, TeleMetrum v2 and EasyMini are all programmed directly
+ over their USB connectors (self programming). TeleMetrum v1, TeleMini and
+ TeleDongle are all programmed by using another device as a
+ programmer (pair programming). It's important to recognize which
+ kind of devices you have before trying to reprogram them.
+ </para>
+ <para>
+ You may wish to begin by ensuring you have current firmware images.
+ These are distributed as part of the AltOS software bundle that
+ also includes the AltosUI ground station program. Newer ground
+ station versions typically work fine with older firmware versions,
+ so you don't need to update your devices just to try out new
+ software features. You can always download the most recent
+ version from <ulink url="http://www.altusmetrum.org/AltOS/"/>.
+ </para>
+ <para>
+ If you need to update the firmware on a TeleDongle, we recommend
+ updating the altimeter first, before updating TeleDongle. However,
+ note that TeleDongle rarely need to be updated. Any firmware version
+ 1.0.1 or later will work, version 1.2.1 may have improved receiver
+ performance slightly.
+ </para>
+ <para>
+ Self-programmable devices (TeleMega, TeleMetrum v2 and EasyMini)
+ are reprogrammed by connecting them to your computer over USB
+ </para>
+ <section>
+ <title>
+ Updating TeleMega, TeleMetrum v2 or EasyMini Firmware
+ </title>
+ <orderedlist inheritnum='inherit' numeration='arabic'>
+ <listitem>
+ <para>
+ Attach a battery and power switch to the target
+ device. Power up the device.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Using a Micro USB cable, connect the target device to your
+ computer's USB socket.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Run AltosUI, and select 'Flash Image' from the File menu.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Select the target device in the Device Selection dialog.
+ </para>
+ </listitem>
+ <listitem>
+ <para>
+ Select the image you want to flash to the device, which
+ should have a name in the form
+ <product>-v<product-version>-<software-version>.ihx, such
+ as TeleMega-v1.0-1.3.0.ihx.
+ </para>
+ </listitem>