1 <?xml version="1.0" encoding="utf-8" ?>
2 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3 "/usr/share/xml/docbook/schema/dtd/4.5/docbookx.dtd">
5 <title>TeleGPS Owner's Manual</title>
6 <subtitle>A recording GPS tracker</subtitle>
9 <firstname>Keith</firstname>
10 <surname>Packard</surname>
14 <holder>Bdale Garbee and Keith Packard</holder>
18 <imagedata fileref="telegps-v1.0-top.jpg" width="4in"/>
23 This document is released under the terms of the
24 <ulink url="http://creativecommons.org/licenses/by-sa/3.0/">
25 Creative Commons ShareAlike 3.0
32 <revnumber>1.4</revnumber>
33 <date>13 June 2014</date>
41 <title>Acknowledgements</title>
43 Have fun using these products, and we hope to meet all of you
44 out on the rocket flight line somewhere.
47 NAR #87103, TRA #12201
50 NAR #88757, TRA #12200
55 <title>Quick Start Guide</title>
57 TeleGPS is designed to be easy to use. Requiring no external
58 components, flying takes just a few steps.
61 First, download and install the software from <ulink
62 url="http://altusmetrum.org/AltOS"/>. This will make sure that
63 you have the right device drivers installed.
66 Next, plug in the battery and USB cable and connect TeleGPS to
67 your computer. This will charge the battery and allow you to
71 Start the TeleGPS application and set the callsign and frequency
72 on your TeleGPS device; refer to the Configure TeleGPS section
73 in the TeleGPS Application chapter for instructions.
76 Unplug TeleGPS when the battery charger light goes green. This
77 will enable the radio and logging portions of the TeleGPS
81 Connect TeleDongle to your computer and start TeleGPS or start
82 AltosDroid on your android device and connect to TeleBT. Set the
83 frequency to match the TeleGPS and you should be receiving telemetry.
87 <title>Handling Precautions</title>
89 All Altus Metrum products are sophisticated electronic devices.
90 When handled gently and properly installed in an air-frame, they
91 will deliver impressive results. However, as with all electronic
92 devices, there are some precautions you must take.
95 The Lithium polymer batteries have an
96 extraordinary power density. This is great because we can fly with
97 much less battery mass... but if they are punctured
98 or their contacts are allowed to short, they can and will release their
100 Thus we recommend that you take some care when handling TeleGPS
101 to keep conductive material from coming in contact with the exposed metal elements.
104 As with all other rocketry electronics, Altus Metrum devices must
105 be protected from exposure to corrosive motor exhaust and ejection
110 <title>TeleGPS Hardware</title>
112 <title>Hooking Up Lithium Polymer Batteries</title>
114 TeleGPS has a two pin JST PH series connector to connect up
115 a single-cell Lithium Polymer cell (3.7V nominal). You can
116 purchase matching batteries from the Altus Metrum store, or
117 other vendors, or you can make your own. Pin 1 of the
118 connector is positive, pin 2 is negative. Spark Fun sells a
119 cable with the connector attached, which they call a <ulink
120 url="https://www.sparkfun.com/products/9914">JST Jumper 2
121 Wire Assembly</ulink>.
124 Many RC vendors also sell lithium polymer batteries with
125 this same connector. All that we have found use the opposite
126 polarity, and if you use them that way, you will damage or
131 <title>On-board Data Recording</title>
133 TeleGPS logs GPS data at a user-configurable rate. Data are
134 logged to a 2MB on-board flash memory part, which can be
135 partitioned into several equal-sized blocks, one for each
136 flight. 64kB of this storage are reserved to hold
137 configuration data, leaving 1984kB for flight data.
140 The on-board flash is partitioned into separate flight logs,
141 each of a fixed maximum size. Increase the maximum size of
142 each log and you reduce the number of flights that can be
143 stored. Decrease the size and you can store more flights.
146 To compute the amount of space needed for a single log, you
147 can divide the expected time (in seconds) by the sample period
148 (by default, 1 second per sample) and then multiply the result
149 by 32 bytes per sample. For instance, a sample period of 1
150 second and a flight lasting one hour will take 32 * 3600 =
151 115200 bytes. TeleGPS does try to reduce log space used by not
152 recording position information when it isn't moving, so actual
153 space consumed may be less than this.
156 The default size allows for four flights of 496kB each, which
157 provides over four hours of logging at 1 sample per second.
160 TeleGPS will not overwrite existing flight data, so be sure to
161 download flight data and erase it from the onboard flash
162 before it fills up. TeleGPS will still report telemetry even
163 if memory is full, so the only thing you will lose is the
168 <title>Installation</title>
170 The battery connectors are a standard 2-pin JST connector and
171 match batteries sold by Spark Fun. These batteries are
172 single-cell Lithium Polymer batteries that nominally provide 3.7
173 volts. Other vendors sell similar batteries for RC aircraft
174 using mating connectors, however the polarity for those is
175 generally reversed from the batteries used by Altus Metrum
176 products. In particular, the Tenergy batteries supplied for use
177 in Featherweight flight computers are not compatible with Altus
178 Metrum flight computers or battery chargers. <emphasis>Check
179 polarity and voltage before connecting any battery not purchased
180 from Altus Metrum or Spark Fun.</emphasis>
183 TeleGPS uses an integrate GPS patch antenna and won't
184 receive GPS signals if installed inside a metal or carbon
185 fiber compartment. Test GPS reception and telemetry
186 transmission with the system installed and all other
187 electronics powered up to verify signal reception and make
188 sure there isn't any interference from other systems.
193 <title>System Operation</title>
195 <title>GFSK Telemetry</title>
197 TeleGPS's native telemetry system doesn't use a 'normal packet
198 radio' mode like APRS because it's not very efficient. The
199 GFSK modulation we use is FSK with the base-band pulses passed
200 through a Gaussian filter before they go into the modulator to
201 limit the transmitted bandwidth. When combined with forward
202 error correction and interleaving, this allows us to have a
203 very robust 19.2 kilobit data link with only 10-40 milliwatts
204 of transmit power, a whip antenna in the rocket, and a
205 hand-held Yagi on the ground. We've had flights to above 21k
206 feet AGL with great reception, and calculations suggest we
207 should be good to well over 40k feet AGL with a 5-element yagi
208 on the ground with our 10mW units and over 100k feet AGL with
215 TeleGPS can send APRS if desired, and the
216 interval between APRS packets can be configured. As each APRS
217 packet takes a full second to transmit, we recommend an
218 interval of at least 5 seconds to avoid consuming too much
219 battery power or radio channel bandwidth. You can configure
220 the APRS interval using AltosUI; that process is described in
221 the Configure Altimeter section of the AltosUI chapter.
224 AltOS uses the APRS compressed position report data format,
225 which provides for higher position precision and shorter
226 packets than the original APRS format. It also includes
227 altitude data, which is invaluable when tracking rockets. We
228 haven't found a receiver which doesn't handle compressed
229 positions, but it's just possible that you have one, so if you
230 have an older device that can receive the raw packets but
231 isn't displaying position information, it's possible that this
235 The APRS packet format includes a comment field that can have
236 arbitrary text in it. AltOS uses this to send status
237 information about the flight computer. It sends four fields as
238 shown in the following table.
241 <title>Altus Metrum APRS Comments</title>
242 <?dbfo keep-together="always"?>
243 <tgroup cols='3' align='center' colsep='1' rowsep='1'>
244 <colspec align='center' colwidth='*' colname='Field'/>
245 <colspec align='center' colwidth='*' colname='Example'/>
246 <colspec align='center' colwidth='4*' colname='Description'/>
249 <entry align='center'>Field</entry>
250 <entry align='center'>Example</entry>
251 <entry align='center'>Description</entry>
258 <entry>GPS Status U for unlocked, L for locked</entry>
263 <entry>Number of Satellites in View</entry>
268 <entry>Battery Voltage</entry>
274 Here's an example of an APRS comment showing GPS lock with 6
275 satellites in view and a battery at 4.0V.
281 Make sure your primary battery is above 3.8V and GPS is locked
282 with at least 5 or 6 satellites in view before starting. If GPS
283 is switching between L and U regularly, then it doesn't have a
284 good lock and you should wait until it becomes stable.
287 If the GPS receiver loses lock, the APRS data transmitted will
288 contain the last position for which GPS lock was
289 available. You can tell that this has happened by noticing
290 that the GPS status character switches from 'L' to 'U'. Before
291 GPS has locked, APRS will transmit zero for latitude,
292 longitude and altitude.
296 <title>Configurable Parameters</title>
298 Configuring TeleGPS is very
299 simple; the few configurable parameters can all be set
300 using the TeleGPS application over USB. Read
301 the Configure TeleGPS section in the TeleGPS Software chapter below
302 for more information.
305 <title>Radio Frequency</title>
307 Altus Metrum boards support radio frequencies in the 70cm
308 band. By default, the configuration interface provides a
309 list of 10 “standard” frequencies in 100kHz channels starting at
310 434.550MHz. However, the firmware supports use of
311 any 50kHz multiple within the 70cm band. At any given
312 launch, we highly recommend coordinating when and by whom each
313 frequency will be used to avoid interference. And of course, both
314 TeleGPS and the receiver must be configured to the same
315 frequency to successfully communicate with each other.
319 <title>Callsign</title>
321 This sets the callsign used for telemetry and APRS to
326 <title>Telemetry/RDF/APRS Enable</title>
328 You can completely disable the radio, if necessary, leaving
329 TeleGPS only logging data to internal memory.
333 <title>APRS Interval</title>
335 This selects how often APRS packets are transmitted. Set
336 this to zero to disable APRS without also disabling the
337 regular telemetry and RDF transmissions. As APRS takes a
338 full second to transmit a single position report, we
339 recommend sending packets no more than once every 5 seconds.
343 <title>Maximum Flight Log</title>
345 Changing this value will set the maximum amount of flight
346 log storage that an individual flight will use. The
347 available storage is divided into as many flights of the
348 specified size as can fit in the available space. You can
349 download and erase individual flight logs. If you fill up
350 the available storage, future flights will not get logged
351 until you erase some of the stored ones.
355 <title>Logging Trigger Motion</title>
357 If TeleGPS moves less than this distance over a long period
358 of time, it will not log that location, saving storage space.
362 <title>Position Reporting Interval</title>
364 This sets how often TeleGPS reports position information via
365 telemetry and to the on-board log. Reducing this value will
366 save power and logging memory consumption.
372 <title>TeleGPS Application</title>
374 The TeleGPS application provides a graphical user interface for
375 interacting with the Altus Metrum product family. TeleGPS can
376 monitor telemetry data, configure devices and many other
377 tasks. The primary interface window is for displaying data
378 received over the telemetry link. There are additional
379 tasks available from the main window menu bar. This chapter
380 is split into sections, each of which documents one of the tasks
381 provided from the top-level toolbar.
384 <title>Telemetry Monitoring</title>
386 This is the window brought up when you start the
387 application. If you have a TeleDongle device connected to the
388 computer, it will automatically be selected for telemetry monitoring
391 All telemetry data received are automatically recorded in
392 suitable log files. The name of the files includes the current
393 date and TeleGPS serial and flight numbers.
396 The radio frequency being monitored by the TeleDongle device
397 is displayed at the top of the window. You can configure the
398 frequency by clicking on the frequency box and selecting the
399 desired frequency. The TeleGPS application remembers the last
400 frequency selected for each TeleDongle and selects that
401 automatically the next time you use that device.
404 Below the TeleDongle frequency selector, the window contains a few
405 significant pieces of information about the altimeter providing
406 the telemetry data stream:
410 <para>The configured call-sign</para>
413 <para>The device serial number</para>
416 <para>The flight number. TeleGPS remembers how many
422 The Received Signal Strength Indicator value. This lets
423 you know how strong a signal TeleDongle is receiving. The
424 radio inside TeleDongle operates down to about -100dBm;
425 weaker signals may not be receivable. The packet link uses
426 error detection and correction techniques which prevent
427 incorrect data from being reported.
432 The age of the displayed data, in seconds since the last
433 successfully received telemetry packet. In normal operation
434 this will stay in the low single digits. If the number starts
435 counting up, then you are no longer receiving data over the radio
436 link from the flight computer.
441 Finally, the largest portion of the window contains a set of
442 tabs, each of which contain some information about the TeleGPS
443 board. The final 'table' tab displays many of the raw telemetry
444 values in one place in a spreadsheet-like format.
449 The Map tab shows the TeleGPS track over time on top of map
450 data making it easy to locate the device.
455 <imagedata fileref="telegps-map.png" width="5.5in"/>
460 The map's default scale is approximately 3m (10ft) per pixel. The map
461 can be dragged using the left mouse button. The map will attempt
462 to keep the rocket roughly centered while data is being received.
465 You can adjust the style of map and the zoom level with
466 buttons on the right side of the map window. You can draw a
467 line on the map by moving the mouse over the map with a
468 button other than the left one pressed, or by pressing the
469 left button while also holding down the shift key. The
470 length of the line in real-world units will be shown at the
474 Images are fetched automatically via the Google Maps Static API,
475 and cached on disk for reuse. If map images cannot be downloaded,
476 the rocket's path will be traced on a dark gray background
480 You can pre-load images for your favorite launch sites
481 before you leave home; check out the 'Preload Maps' section below.
485 <title>Location</title>
487 The Location tab shows the raw GPS data received from TeleGPS.
492 <imagedata fileref="telegps-location.png" width="5.5in"/>
498 <title>Status</title>
500 The Status tab shows data relative to the location of
501 TeleGPS when the application first received telemetry from
507 <imagedata fileref="telegps-status.png" width="5.5in"/>
515 The Table tab shows detailed information about the GPS
521 <imagedata fileref="telegps-table.png" width="5.5in"/>
539 <title>TeleGPS Menus</title>
541 TeleGPS has three or four menus at the top of the window:
547 New Window, Graph Data, Export Data, Load Maps, Preferences, Close and Exit
555 Connect Device, Disconnect and Scan Channels
563 Download Data, Configure Device and Flash Device
568 <term>Frequency</term>
571 This shows the current monitoring frequency with a
572 drop-down menu listing other configured
573 frequencies. You can change the set of frequencies
574 shown here from the Preferences dialog. This menu is
575 only shown when the TeleGPS application is connected
576 to a TeleDongle or TeleBT device.
583 <title>New Window</title>
585 This creates another telemetry monitoring window, in case
586 you have multiple TeleDongle devices connected to the
591 <title>Graph Data</title>
593 This brings up a file dialog to load a saved log, either
594 a .telem file of recorded telemetry or .eeprom of saved
595 data from on-board memory. It looks a bit like the flight
596 monitoring window, using a selection of tabs to show
597 different views of the saved data.
602 The Graph tab shows a plot of the the GPS data
603 collected. The X axis is time in seconds; there are a
604 variety of Y axes available for different kinds of data.
609 <imagedata fileref="telegps-graph-graph.png" width="6in" scalefit="1"/>
615 <title>Configure Graph</title>
619 <imagedata fileref="telegps-graph-configure.png" width="6in" scalefit="1"/>
624 This selects which graph elements to show, and, at the
625 bottom, lets you switch between metric and imperial units
629 <title>Statistics</title>
633 <imagedata fileref="telegps-graph-stats.png" width="6in" scalefit="1"/>
638 Shows overall data computed from the flight.
646 <imagedata fileref="telegps-graph-map.png" width="6in" scalefit="1"/>
651 Shows a map of the area overlaid with the GPS track. As with
652 the telemetry monitoring window, you can select the style
653 of map and zoom level using buttons along the side;
654 you can scroll the map by dragging within the map pressing
655 the left button and you can draw a line to measure
656 distances using either the left button with the shift key,
662 <title>Export Data</title>
664 This tool takes the raw data files and makes them available for
665 external analysis. When you select this button, you are prompted to
666 select a data file, which can be either a .eeprom or .telem.
667 The .eeprom files contain higher resolution and more continuous data,
668 while .telem files contain receiver signal strength information.
669 Next, a second dialog appears which is used to select
670 where to write the resulting file. It has a selector to choose
671 between CSV and KML file formats.
674 <title>Comma Separated Value Format</title>
676 This is a text file containing the data in a form suitable for
677 import into a spreadsheet or other external data analysis
678 tool. The first few lines of the file contain the version and
679 configuration information from TeleGPS, then
680 there is a single header line which labels all of the
681 fields. All of these lines start with a '#' character which
682 many tools can be configured to skip over.
685 The remaining lines of the file contain the data, with each
686 field separated by a comma and at least one space. All of
687 the sensor values are converted to standard units, with the
688 barometric data reported in both pressure, altitude and
689 height above pad units.
693 <title>Keyhole Markup Language (for Google Earth)</title>
695 This is the format used by Google Earth to provide an overlay
696 within that application. With this, you can use Google Earth to
697 see the whole flight path in 3D.
702 <title>Load Maps</title>
706 <imagedata fileref="load-maps.png" width="5.2in" scalefit="1"/>
711 Before using TeleGPS, you can use Load Maps to load map data
712 in case you don't have access to the internet while
716 There's a drop-down menu of rocket launch sites we know
717 about; if your favorites aren't there, please let us know
718 the lat/lon and name of the site. The contents of this list
719 are actually downloaded from our server at run-time, so as
720 new sites are sent in, they'll get automatically added to
721 this list. If the launch site isn't in the list, you can
722 manually enter the lat/lon values
725 There are four different kinds of maps you can view; you can
726 select which to download by selecting as many as you like from
733 A combination of satellite imagery and road data. This
739 <term>Satellite</term>
742 Just the satellite imagery without any annotation.
750 Roads, political boundaries and a few geographic features.
758 Contour intervals and shading that show hills and
766 You can specify the range of zoom levels to download; smaller
767 numbers show more area with less resolution. The default
768 level, 0, shows about 3m/pixel. One zoom level change
769 doubles or halves that number.
772 The Tile Radius value sets how large an area around the center
773 point to download. Each tile is 512x512 pixels, and the
774 'radius' value specifies how many tiles away from the center
775 will be downloaded. Specify a radius of 0 and you get only the
776 center tile. A radius of 1 loads a 3x3 grid, centered on the
780 Clicking the 'Load Map' button will fetch images from Google
781 Maps; note that Google limits how many images you can fetch at
782 once, so if you load more than one launch site, you may get
783 some gray areas in the map which indicate that Google is tired
784 of sending data to you. Try again later.
788 <title>Preferences</title>
792 <imagedata fileref="telegps-preferences.png" width="2.4in" scalefit="1"/>
797 <title>Voice Settings</title>
799 AltosUI provides voice announcements during flight so that you
800 can keep your eyes on the sky and still get information about
801 the current flight status. However, sometimes you don't want
808 <para>Turns all voice announcements on and off</para>
812 <term>Test Voice</term>
815 Plays a short message allowing you to verify
816 that the audio system is working and the volume settings
824 <title>Log Directory</title>
826 AltosUI logs all telemetry data and saves all TeleMetrum flash
827 data to this directory. This directory is also used as the
828 staring point when selecting data files for display or export.
831 Click on the directory name to bring up a directory choosing
832 dialog, select a new directory and click 'Select Directory' to
833 change where AltosUI reads and writes data files.
837 <title>Callsign</title>
839 This value is transmitted in each command packet sent from
840 TeleDongle and received from an altimeter. It is not used in
841 telemetry mode, as the callsign configured in the altimeter board
842 is included in all telemetry packets. Configure this
843 with the AltosUI operators call sign as needed to comply with
844 your local radio regulations.
847 Note that to successfully command a flight computer over the radio
848 (to configure the altimeter, monitor idle, or fire pyro charges),
849 the callsign configured here must exactly match the callsign
850 configured in the flight computer. This matching is case
855 <title>Imperial Units</title>
857 This switches between metric units (meters) and imperial
858 units (feet and miles). This affects the display of values
859 use during flight monitoring, configuration, data graphing
860 and all of the voice announcements. It does not change the
861 units used when exporting to CSV files, those are always
862 produced in metric units.
866 <title>Serial Debug</title>
868 This causes all communication with a connected device to be
869 dumped to the console from which AltosUI was started. If
870 you've started it from an icon or menu entry, the output
871 will simply be discarded. This mode can be useful to debug
872 various serial communication issues.
876 <title>Font Size</title>
878 Selects the set of fonts used in the flight monitor
879 window. Choose between the small, medium and large sets.
883 <title>Look & Feel</title>
885 Adjust the style of the windows. By default, the TeleGPS
886 application attempts to blend in with the native style.
890 <title>Manage Frequencies</title>
892 This brings up a dialog where you can configure the set of
893 frequencies shown in the various frequency menus. You can
894 add as many as you like, or even reconfigure the default
895 set. Changing this list does not affect the frequency
896 settings of any devices, it only changes the set of
897 frequencies shown in the menus.
904 This closes the current window, leaving any other windows
905 open and the application running.
911 This closes all TeleGPS windows and terminates the application.
915 <title>Connect Device</title>
917 Selecting this item brings up a dialog box listing all of
918 the connected TeleDongle devices. When you choose one of
919 these, AltosUI will display telemetry data as received by
920 the selected TeleDongle device.
925 <imagedata fileref="device-selection.png" width="3.1in"/>
931 <title>Disconnect</title>
933 Disconnects the currently connected TeleDongle or TeleBT
937 <title>Scan Channels</title>
939 Scans the configured set of frequencies looking for
940 telemetry signals. A list of all of the discovered signals
941 is show; selecting one of those and clicking on 'Monitor'
942 will select that frequency in the associated TeleGPS
948 <imagedata fileref="telegps-scan.png" width="3.1in"/>
954 <title>Download Data</title>
956 TeleGPS records data to its internal flash memory.
957 On-board data is recorded at the same rate as telemetry
958 but is not subject to radio drop-outs. As
959 such, it generally provides a more complete and precise record.
960 The 'Download Data' menu entry allows you to read the
961 flash memory and write it to disk.
964 Select the 'Download Data' menu entry to bring up a list of
965 connected TeleGPS devices. After the device has been
966 selected, a dialog showing the data stored in the
967 device will be shown allowing you to select which entries to
968 download and which to delete. You must erase flights in order for the space they
969 consume to be reused by another track. This prevents
970 accidentally losing data if you neglect to download
971 data before starting TeleGPS again. Note that if there is no more
972 space available in the device, then no data will be recorded.
975 The file name for each data log is computed automatically
976 from the recorded date, altimeter serial number and flight
981 <title>Configure Device</title>
985 <imagedata fileref="telegps-configure.png" width="3.6in" scalefit="1"/>
990 Select this button and then select any connected TeleGPS
991 device from the list provided.
994 The first few lines of the dialog provide information about the
995 connected device, including the product name,
996 software version and hardware serial number. Below that are the
997 individual configuration entries.
1000 At the bottom of the dialog, there are four buttons:
1007 This writes any changes to the
1008 configuration parameter block in flash memory. If you don't
1009 press this button, any changes you make will be lost.
1017 This resets the dialog to the most recently saved values,
1018 erasing any changes you have made.
1026 This reboots the device. This will restart logging for
1027 a new flight number, if any log information has been
1028 saved for the current flight.
1036 This closes the dialog. Any unsaved changes will be
1043 The rest of the dialog contains the parameters to be configured.
1046 <title>Frequency</title>
1048 This configures which of the frequencies to use for both
1049 telemetry and packet command mode. Note that if you set this
1050 value via packet command mode, the TeleDongle frequency will
1051 also be automatically reconfigured to match so that
1052 communication will continue afterwards.
1056 <title>RF Calibration</title>
1058 The radios in every Altus Metrum device are calibrated at the
1059 factory to ensure that they transmit and receive on the
1060 specified frequency. If you need to you can adjust the calibration
1061 by changing this value. Do not do this without understanding what
1062 the value means, read the appendix on calibration and/or the source
1063 code for more information. To change a TeleDongle's calibration,
1064 you must reprogram the unit completely.
1068 <title>Telemetry/RDF/APRS Enable</title>
1070 Enables the radio for transmission during flight. When
1071 disabled, the radio will not transmit anything during flight
1076 <title>APRS Interval</title>
1078 How often to transmit GPS information via APRS (in
1079 seconds). When set to zero, APRS transmission is
1080 disabled. This option is available on TeleMetrum v2 and
1081 TeleMega boards. TeleMetrum v1 boards cannot transmit APRS
1082 packets. Note that a single APRS packet takes nearly a full
1083 second to transmit, so enabling this option will prevent
1084 sending any other telemetry during that time.
1088 <title>Callsign</title>
1090 This sets the call sign included in each telemetry packet. Set this
1091 as needed to conform to your local radio regulations.
1095 <title>Maximum Log Size</title>
1097 This sets the space (in kilobytes) allocated for each data
1098 log. The available space will be divided into chunks of this
1099 size. A smaller value will allow more logs to be stored,
1100 a larger value will record data for longer times.
1104 <title>Logging Trigger Motion</title>
1106 If TeleGPS moves less than this distance over a long period
1107 of time, it will not log that location, saving storage space.
1111 <title>Position Reporting Interval</title>
1113 This sets how often TeleGPS reports position information via
1114 telemetry and to the on-board log. Reducing this value will
1115 save power and logging memory consumption.
1120 <title>Flash Device</title>
1122 This reprograms TeleGPS devices with new firmware. Please
1123 read the directions for flashing devices in the Updating
1124 Device Firmware chapter below.
1130 <title>Updating Device Firmware</title>
1132 TeleGPS is programmed directly over its USB connectors.
1135 You may wish to begin by ensuring you have current firmware images.
1136 These are distributed as part of the TeleGPS software bundle that
1137 also includes the TeleGPS ground station program. Newer ground
1138 station versions typically work fine with older firmware versions,
1139 so you don't need to update your devices just to try out new
1140 software features. You can always download the most recent
1141 version from <ulink url="http://www.altusmetrum.org/AltOS/"/>.
1145 Updating TeleGPS Firmware
1147 <orderedlist inheritnum='inherit' numeration='arabic'>
1150 Attach a battery and power switch to the target
1151 device. Power up the device.
1156 Using a Micro USB cable, connect the target device to your
1157 computer's USB socket.
1162 Run TeleGPS, and select 'Flash Device' from the Device menu.
1167 Select the target device in the Device Selection dialog.
1172 Select the image you want to flash to the device, which
1173 should have a name in the form
1174 <product>-v<product-version>-<software-version>.ihx, such
1175 as TeleGPS-v1.0-1.4.0.ihx.
1180 Make sure the configuration parameters are reasonable
1181 looking. If the serial number and/or RF configuration
1182 values aren't right, you'll need to change them.
1187 Hit the 'OK' button and the software should proceed to flash
1188 the device with new firmware, showing a progress bar.
1193 Verify that the device is working by using the 'Configure
1194 Altimeter' item to check over the configuration.
1200 <title>Recovering From Self-Flashing Failure</title>
1202 If the firmware loading fails, it can leave the device
1203 unable to boot. Not to worry, you can force the device to
1204 start the boot loader instead, which will let you try to
1205 flash the device again.
1208 On each device, connecting two pins from one of the exposed
1209 connectors will force the boot loader to start, even if the
1210 regular operating system has been corrupted in some way.
1214 <term>TeleMega</term>
1217 Connect pin 6 and pin 1 of the companion connector. Pin 1
1218 can be identified by the square pad around it, and then
1219 the pins could sequentially across the board. Be very
1220 careful to <emphasis>not</emphasis> short pin 8 to
1221 anything as that is connected directly to the battery. Pin
1222 7 carries 3.3V and the board will crash if that is
1223 connected to pin 1, but shouldn't damage the board.
1228 <term>TeleMetrum v2</term>
1231 Connect pin 6 and pin 1 of the companion connector. Pin 1
1232 can be identified by the square pad around it, and then
1233 the pins could sequentially across the board. Be very
1234 careful to <emphasis>not</emphasis> short pin 8 to
1235 anything as that is connected directly to the battery. Pin
1236 7 carries 3.3V and the board will crash if that is
1237 connected to pin 1, but shouldn't damage the board.
1242 <term>EasyMini</term>
1245 Connect pin 6 and pin 1 of the debug connector, which is
1246 the six holes next to the beeper. Pin 1 can be identified
1247 by the square pad around it, and then the pins could
1248 sequentially across the board, making Pin 6 the one on the
1249 other end of the row.
1259 <title>Technical Information</title>
1261 <title>GPS Receiver</title>
1263 TeleGPS uses the u-Blox Max-7Q GPS receiver.
1267 <title>Micro-controller</title>
1269 TeleGPS uses an NXP LPC11U14 micro-controller. This tiny
1270 CPU contains 32kB of flash for the application and 4kB of RAM for
1271 temporary data storage.
1275 <title>Lithium Polymer Battery</title>
1277 Shipping restrictions may prevent us from including a battery
1278 battery with TeleGPS.
1282 <title>Mechanical Considerations</title>
1284 TeleGPS is designed to be rugged enough for typical rocketry
1285 applications. The 4 mounting holes on the board are sized for
1286 use with 4-40 or M3 screws.
1290 <title>On-board data storage</title>
1292 TeleGPS has 2MB of non-volatile storage, separate from the
1293 code storage memory. The TeleGPS firmware uses this to log
1294 information during flight.
1299 <!-- LocalWords: Altusmetrum TeleGPS