</para>
</chapter>
<chapter>
- <title>Hardware Overview</title>
- <para>
- TeleMetrum is a 1 inch by 2¾ inch circuit board. It was designed to
- fit inside coupler for 29mm air-frame tubing, but using it in a tube that
- small in diameter may require some creativity in mounting and wiring
- to succeed! The presence of an accelerometer means TeleMetrum should
- be aligned along the flight axis of the airframe, and by default the 1/4
- wave UHF wire antenna should be on the nose-cone end of the board. The
- antenna wire is about 7 inches long, and wiring for a power switch and
- the e-matches for apogee and main ejection charges depart from the
- fin can end of the board, meaning an ideal "simple" avionics
- bay for TeleMetrum should have at least 10 inches of interior length.
- </para>
- <para>
- TeleMini v1.0 is a ½ inch by 1½ inch circuit board. It was designed to
- fit inside an 18mm air-frame tube, but using it in a tube that
- small in diameter may require some creativity in mounting and wiring
- to succeed! Since there is no accelerometer, TeleMini can be mounted
- in any convenient orientation. The default ¼
- wave UHF wire antenna attached to the center of one end of
- the board is about 7 inches long, and wiring for a power switch and
- the e-matches for apogee and main ejection charges depart from the
- other end of the board, meaning an ideal "simple" avionics
- bay for TeleMini should have at least 9 inches of interior length.
- </para>
- <para>
- TeleMini v2.0 and EasyMini are both built on a 0.8 inch by 1½
- inch circuit board. They're designed to fit in a 24mm coupler
- tube. TeleMini has an antenna, which must be run straight out
- fro the board. Bending or folding it will dramatically reduce RF
- performance. For smaller rockets, it's often best to drill a
- hole in the bulkhead forward of TeleMini and run the antenna
- wire through that and alongside any recovery components
- there. Be careful to seal the hole to prevent ejection gasses
- from passing through the hole and damaging the electronics.
- </para>
- <para>
- TeleMega is a 1¼ inch by 3¼ inch circuit board. It was
- designed to easily fit in a 38mm coupler. Like TeleMetrum,
- TeleMega has an accelerometer and so it must be mounted so that
- the board is aligned with the flight axis. It can be mounted
- either antenna up or down.
- </para>
- <para>
- A typical installation involves attaching
- only a suitable battery, a single pole switch for
- power on/off, and two pairs of wires connecting e-matches for the
- apogee and main ejection charges. All Altus Metrum products are
- designed for use with single-cell batteries with 3.7 volts
- nominal. TeleMini v2.0 and EasyMini may also be used with other
- batteries as long as they supply between 4 and 12 volts.
- </para>
- <para>
- The battery connectors are a standard 2-pin JST connector and
- match batteries sold by Spark Fun. These batteries are
- single-cell Lithium Polymer batteries that nominally provide 3.7
- volts. Other vendors sell similar batteries for RC aircraft
- using mating connectors, however the polarity for those is
- generally reversed from the batteries used by Altus Metrum
- products. In particular, the Tenergy batteries supplied for use
- in Featherweight flight computers are not compatible with Altus
- Metrum flight computers or battery chargers. <emphasis>Check
- polarity and voltage before connecting any battery not purchased
- from Altus Metrum or Spark Fun.</emphasis>
- </para>
- <para>
- By default, we use the unregulated output of the battery directly
- to fire ejection charges. This works marvelously with standard
- low-current e-matches like the J-Tek from MJG Technologies, and with
- Quest Q2G2 igniters. However, if you want or need to use a separate
- pyro battery, check out the "External Pyro Battery" section in this
- manual for instructions on how to wire that up. The altimeters are
- designed to work with an external pyro battery of no more than 15 volts.
- </para>
- <para>
- Ejection charges are wired directly to the screw terminal block
- at the aft end of the altimeter. You'll need a very small straight
- blade screwdriver for these screws, such as you might find in a
- jeweler's screwdriver set.
- </para>
- <para>
- Except for TeleMini v1.0, the flight computers also use the
- screw terminal block for the power switch leads. On TeleMini v1.0,
- the power switch leads are soldered directly to the board and
- can be connected directly to a switch.
- </para>
- <para>
- For most air-frames, the integrated antennas are more than
- adequate. However, if you are installing in a carbon-fiber or
- metal electronics bay which is opaque to RF signals, you may need to
- use off-board external antennas instead. In this case, you can
- order an altimeter with an SMA connector for the UHF antenna
- connection, and, on TeleMetrum v1, you can unplug the integrated GPS
- antenna and select an appropriate off-board GPS antenna with
- cable terminating in a U.FL connector.
- </para>
+ <title>Altus Metrum Hardware</title>
+ <section>
+ <title>Overview</title>
+ <para>
+ Here's the full set of Altus Metrum products, both in
+ production and retired.
+ </para>
+ <table frame='all'>
+ <title>Altus Metrum Electronics</title>
+ <tgroup cols='8' align='center' colsep='1' rowsep='1'>
+ <colspec align='center' colwidth='*' colname='Device'/>
+ <colspec align='center' colwidth='*' colname='Barometer'/>
+ <colspec align='center' colwidth='*' colname='Z-axis accelerometer'/>
+ <colspec align='center' colwidth='*' colname='GPS'/>
+ <colspec align='center' colwidth='*' colname='3D sensors'/>
+ <colspec align='center' colwidth='*' colname='Storage'/>
+ <colspec align='center' colwidth='*' colname='RF'/>
+ <colspec align='center' colwidth='*' colname='Battery'/>
+ <thead>
+ <row>
+ <entry align='center'>Device</entry>
+ <entry align='center'>Barometer</entry>
+ <entry align='center'>Z-axis accelerometer</entry>
+ <entry align='center'>GPS</entry>
+ <entry align='center'>3D sensors</entry>
+ <entry align='center'>Storage</entry>
+ <entry align='center'>RF Output</entry>
+ <entry align='center'>Battery</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>TeleMetrum v1.0</entry>
+ <entry><para>MP3H6115 10km (33k')</para></entry>
+ <entry><para>MMA2202 50g</para></entry>
+ <entry>SkyTraq</entry>
+ <entry>-</entry>
+ <entry>1MB</entry>
+ <entry>10mW</entry>
+ <entry>3.7V</entry>
+ </row>
+ <row>
+ <entry>TeleMetrum v1.1</entry>
+ <entry><para>MP3H6115 10km (33k')</para></entry>
+ <entry><para>MMA2202 50g</para></entry>
+ <entry>SkyTraq</entry>
+ <entry>-</entry>
+ <entry>2MB</entry>
+ <entry>10mW</entry>
+ <entry>3.7V</entry>
+ </row>
+ <row>
+ <entry>TeleMetrum v1.2</entry>
+ <entry><para>MP3H6115 10km (33k')</para></entry>
+ <entry><para>ADXL78 70g</para></entry>
+ <entry>SkyTraq</entry>
+ <entry>-</entry>
+ <entry>2MB</entry>
+ <entry>10mW</entry>
+ <entry>3.7V</entry>
+ </row>
+ <row>
+ <entry>TeleMetrum v2.0</entry>
+ <entry><para>MS5607 30km (100k')</para></entry>
+ <entry><para>MMA6555 102g</para></entry>
+ <entry>uBlox Max-7Q</entry>
+ <entry>-</entry>
+ <entry>8MB</entry>
+ <entry>40mW</entry>
+ <entry>3.7V</entry>
+ </row>
+ <row>
+ <entry><para>TeleMini <?linebreak?>v1.0</para></entry>
+ <entry><para>MP3H6115 10km (33k')</para></entry>
+ <entry>-</entry>
+ <entry>-</entry>
+ <entry>-</entry>
+ <entry>5kB</entry>
+ <entry>10mW</entry>
+ <entry>3.7V</entry>
+ </row>
+ <row>
+ <entry>TeleMini <?linebreak?>v2.0</entry>
+ <entry><para>MS5607 30km (100k')</para></entry>
+ <entry>-</entry>
+ <entry>-</entry>
+ <entry>-</entry>
+ <entry>1MB</entry>
+ <entry>10mW</entry>
+ <entry>3.7-12V</entry>
+ </row>
+ <row>
+ <entry>EasyMini <?linebreak?>v1.0</entry>
+ <entry><para>MS5607 30km (100k')</para></entry>
+ <entry>-</entry>
+ <entry>-</entry>
+ <entry>-</entry>
+ <entry>1MB</entry>
+ <entry>-</entry>
+ <entry>3.7-12V</entry>
+ </row>
+ <row>
+ <entry>TeleMega <?linebreak?>v1.0</entry>
+ <entry><para>MS5607 30km (100k')</para></entry>
+ <entry><para>MMA6555 102g</para></entry>
+ <entry>uBlox Max-7Q</entry>
+ <entry><para>MPU6000 HMC5883</para></entry>
+ <entry>8MB</entry>
+ <entry>40mW</entry>
+ <entry>3.7V</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <table frame='all'>
+ <title>Altus Metrum Boards</title>
+ <tgroup cols='6' align='center' colsep='1' rowsep='1'>
+ <colspec align='center' colwidth='*' colname='Device'/>
+ <colspec align='center' colwidth='*' colname='Connectors'/>
+ <colspec align='center' colwidth='*' colname='Screw Terminals'/>
+ <colspec align='center' colwidth='*' colname='Width'/>
+ <colspec align='center' colwidth='*' colname='Length'/>
+ <colspec align='center' colwidth='*' colname='Tube Size'/>
+ <thead>
+ <row>
+ <entry align='center'>Device</entry>
+ <entry align='center'>Connectors</entry>
+ <entry align='center'>Screw Terminals</entry>
+ <entry align='center'>Width</entry>
+ <entry align='center'>Length</entry>
+ <entry align='center'>Tube Size</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>TeleMetrum</entry>
+ <entry><para>
+ Antenna<?linebreak?>
+ Debug<?linebreak?>
+ Companion<?linebreak?>
+ USB<?linebreak?>
+ Battery
+ </para></entry>
+ <entry><para>Apogee pyro <?linebreak?>Main pyro <?linebreak?>Switch</para></entry>
+ <entry>1 inch (2.54cm)</entry>
+ <entry>2 ¾ inch (6.99cm)</entry>
+ <entry>29mm coupler</entry>
+ </row>
+ <row>
+ <entry><para>TeleMini <?linebreak?>v1.0</para></entry>
+ <entry><para>
+ Antenna<?linebreak?>
+ Debug<?linebreak?>
+ Battery
+ </para></entry>
+ <entry><para>
+ Apogee pyro <?linebreak?>
+ Main pyro
+ </para></entry>
+ <entry>½ inch (1.27cm)</entry>
+ <entry>1½ inch (3.81cm)</entry>
+ <entry>18mm aiframe</entry>
+ </row>
+ <row>
+ <entry>TeleMini <?linebreak?>v2.0</entry>
+ <entry><para>
+ Antenna<?linebreak?>
+ Debug<?linebreak?>
+ USB<?linebreak?>
+ Battery
+ </para></entry>
+ <entry><para>
+ Apogee pyro <?linebreak?>
+ Main pyro <?linebreak?>
+ Battery <?linebreak?>
+ Switch
+ </para></entry>
+ <entry>0.8 inch (2.03cm)</entry>
+ <entry>1½ inch (3.81cm)</entry>
+ <entry>24mm coupler</entry>
+ </row>
+ <row>
+ <entry>EasyMini</entry>
+ <entry><para>
+ Debug<?linebreak?>
+ USB<?linebreak?>
+ Battery
+ </para></entry>
+ <entry><para>
+ Apogee pyro <?linebreak?>
+ Main pyro <?linebreak?>
+ Battery <?linebreak?>
+ Switch
+ </para></entry>
+ <entry>0.8 inch (2.03cm)</entry>
+ <entry>1½ inch (3.81cm)</entry>
+ <entry>24mm coupler</entry>
+ </row>
+ <row>
+ <entry>TeleMega</entry>
+ <entry><para>
+ Antenna<?linebreak?>
+ Debug<?linebreak?>
+ Companion<?linebreak?>
+ USB<?linebreak?>
+ Battery
+ </para></entry>
+ <entry><para>
+ Apogee pyro <?linebreak?>
+ Main pyro<?linebreak?>
+ Pyro A-D<?linebreak?>
+ Switch<?linebreak?>
+ Pyro battery
+ </para></entry>
+ <entry>1¼ inch (3.18cm)</entry>
+ <entry>3¼ inch (8.26cm)</entry>
+ <entry>38mm coupler</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section>
+ <title>TeleMetrum</title>
+ <para>
+ TeleMetrum is a 1 inch by 2¾ inch circuit board. It was designed to
+ fit inside coupler for 29mm air-frame tubing, but using it in a tube that
+ small in diameter may require some creativity in mounting and wiring
+ to succeed! The presence of an accelerometer means TeleMetrum should
+ be aligned along the flight axis of the airframe, and by default the 1/4
+ wave UHF wire antenna should be on the nose-cone end of the board. The
+ antenna wire is about 7 inches long, and wiring for a power switch and
+ the e-matches for apogee and main ejection charges depart from the
+ fin can end of the board, meaning an ideal "simple" avionics
+ bay for TeleMetrum should have at least 10 inches of interior length.
+ </para>
+ </section>
+ <section>
+ <title>TeleMini</title>
+ <para>
+ TeleMini v1.0 is ½ inches by 1½ inches. It was
+ designed to fit inside an 18mm air-frame tube, but using it in
+ a tube that small in diameter may require some creativity in
+ mounting and wiring to succeed! Since there is no
+ accelerometer, TeleMini can be mounted in any convenient
+ orientation. The default ¼ wave UHF wire antenna attached to
+ the center of one end of the board is about 7 inches long. Two
+ wires for the power switch are connected to holes in the
+ middle of the board. Screw terminals for the e-matches for
+ apogee and main ejection charges depart from the other end of
+ the board, meaning an ideal "simple" avionics bay for TeleMini
+ should have at least 9 inches of interior length.
+ </para>
+ <para>
+ TeleMini v2.0 is 0.8 inches by 1½ inches. It adds more
+ on-board data logging memory, a built-in USB connector and
+ screw terminals for the battery and power switch. The larger
+ board fits in a 24mm coupler. There's also a battery connector
+ for a LiPo battery if you want to use one of those.
+ </para>
+ </section>
+ <section>
+ <title>EasyMini</title>
+ <para>
+ EasyMini is built on a 0.8 inch by 1½ inch circuit board. It's
+ designed to fit in a 24mm coupler tube. The connectors and
+ screw terminals match TeleMini, so you can swap an EasyMini
+ with a TeleMini.
+ </para>
+ </section>
+ <section>
+ <title>TeleMega</title>
+ <para>
+ TeleMega is a 1¼ inch by 3¼ inch circuit board. It was
+ designed to easily fit in a 38mm coupler. Like TeleMetrum,
+ TeleMega has an accelerometer and so it must be mounted so that
+ the board is aligned with the flight axis. It can be mounted
+ either antenna up or down.
+ </para>
+ </section>
+ <section>
+ <title>Flight Data Recording</title>
+ <para>
+ Each flight computer logs data at 100 samples per second
+ during ascent and 10 samples per second during descent, except
+ for TeleMini v1.0, which records ascent at 10 samples per
+ second and descent at 1 sample per second. Data are logged to
+ an on-board flash memory part, which can be partitioned into
+ several equal-sized blocks, one for each flight.
+ </para>
+ <table frame='all'>
+ <title>Data Storage on Altus Metrum altimeters</title>
+ <tgroup cols='4' align='center' colsep='1' rowsep='1'>
+ <colspec align='center' colwidth='*' colname='Device'/>
+ <colspec align='center' colwidth='*' colname='Bytes per sample'/>
+ <colspec align='center' colwidth='*' colname='Total storage'/>
+ <colspec align='center' colwidth='*' colname='Minutes of
+ full-rate'/>
+ <thead>
+ <row>
+ <entry align='center'>Device</entry>
+ <entry align='center'>Bytes per Sample</entry>
+ <entry align='center'>Total Storage</entry>
+ <entry align='center'>Minutes at Full Rate</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>TeleMetrum v1.0</entry>
+ <entry>8</entry>
+ <entry>1MB</entry>
+ <entry>20</entry>
+ </row>
+ <row>
+ <entry>TeleMetrum v1.1 v1.2</entry>
+ <entry>8</entry>
+ <entry>2MB</entry>
+ <entry>40</entry>
+ </row>
+ <row>
+ <entry>TeleMetrum v2.0</entry>
+ <entry>16</entry>
+ <entry>8MB</entry>
+ <entry>80</entry>
+ </row>
+ <row>
+ <entry>TeleMini v1.0</entry>
+ <entry>2</entry>
+ <entry>5kB</entry>
+ <entry>4</entry>
+ </row>
+ <row>
+ <entry>TeleMini v2.0</entry>
+ <entry>16</entry>
+ <entry>1MB</entry>
+ <entry>10</entry>
+ </row>
+ <row>
+ <entry>EasyMini</entry>
+ <entry>16</entry>
+ <entry>1MB</entry>
+ <entry>10</entry>
+ </row>
+ <row>
+ <entry>TeleMega</entry>
+ <entry>32</entry>
+ <entry>8MB</entry>
+ <entry>40</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <para>
+ The on-board flash is partitioned into separate flight logs,
+ each of a fixed maximum size. Increase the maximum size of
+ each log and you reduce the number of flights that can be
+ stored. Decrease the size and you can store more flights.
+ </para>
+ <para>
+ Configuration data is also stored in the flash memory on
+ TeleMetrum v1.x, TeleMini and EasyMini. This consumes 64kB
+ of flash space. This configuration space is not available
+ for storing flight log data. TeleMetrum v2.0 and TeleMega
+ store configuration data in a bit of eeprom available within
+ the processor chip, leaving that space available in flash for
+ more flight data.
+ </para>
+ <para>
+ To compute the amount of space needed for a single flight, you
+ can multiply the expected ascent time (in seconds) by 100
+ times bytes-per-sample, multiply the expected descent time (in
+ seconds) by 10 times the bytes per sample and add the two
+ together. That will slightly under-estimate the storage (in
+ bytes) needed for the flight. For instance, a TeleMetrum v2.0 flight spending
+ 20 seconds in ascent and 150 seconds in descent will take
+ about (20 * 1600) + (150 * 160) = 56000 bytes of storage. You
+ could store dozens of these flights in the on-board flash.
+ </para>
+ <para>
+ The default size allows for several flights on each flight
+ computer, except for TeleMini v1.0, which only holds data for a
+ single flight. You can adjust the size.
+ </para>
+ <para>
+ Altus Metrum flight computers will not overwrite existing
+ flight data, so be sure to download flight data and erase it
+ from the flight computer before it fills up. The flight
+ computer will still successfully control the flight even if it
+ cannot log data, so the only thing you will lose is the data.
+ </para>
+ </section>
+ <section>
+ <title>Installation</title>
+ <para>
+ A typical installation involves attaching
+ only a suitable battery, a single pole switch for
+ power on/off, and two pairs of wires connecting e-matches for the
+ apogee and main ejection charges. All Altus Metrum products are
+ designed for use with single-cell batteries with 3.7 volts
+ nominal. TeleMini v2.0 and EasyMini may also be used with other
+ batteries as long as they supply between 4 and 12 volts.
+ </para>
+ <para>
+ The battery connectors are a standard 2-pin JST connector and
+ match batteries sold by Spark Fun. These batteries are
+ single-cell Lithium Polymer batteries that nominally provide 3.7
+ volts. Other vendors sell similar batteries for RC aircraft
+ using mating connectors, however the polarity for those is
+ generally reversed from the batteries used by Altus Metrum
+ products. In particular, the Tenergy batteries supplied for use
+ in Featherweight flight computers are not compatible with Altus
+ Metrum flight computers or battery chargers. <emphasis>Check
+ polarity and voltage before connecting any battery not purchased
+ from Altus Metrum or Spark Fun.</emphasis>
+ </para>
+ <para>
+ By default, we use the unregulated output of the battery directly
+ to fire ejection charges. This works marvelously with standard
+ low-current e-matches like the J-Tek from MJG Technologies, and with
+ Quest Q2G2 igniters. However, if you want or need to use a separate
+ pyro battery, check out the "External Pyro Battery" section in this
+ manual for instructions on how to wire that up. The altimeters are
+ designed to work with an external pyro battery of no more than 15 volts.
+
+ </para>
+ <para>
+ Ejection charges are wired directly to the screw terminal block
+ at the aft end of the altimeter. You'll need a very small straight
+ blade screwdriver for these screws, such as you might find in a
+ jeweler's screwdriver set.
+ </para>
+ <para>
+ Except for TeleMini v1.0, the flight computers also use the
+ screw terminal block for the power switch leads. On TeleMini v1.0,
+ the power switch leads are soldered directly to the board and
+ can be connected directly to a switch.
+ </para>
+ <para>
+ For most air-frames, the integrated antennas are more than
+ adequate. However, if you are installing in a carbon-fiber or
+ metal electronics bay which is opaque to RF signals, you may need to
+ use off-board external antennas instead. In this case, you can
+ order an altimeter with an SMA connector for the UHF antenna
+ connection, and, on TeleMetrum v1, you can unplug the integrated GPS
+ antenna and select an appropriate off-board GPS antenna with
+ cable terminating in a U.FL connector.
+ </para>
+ </section>
</chapter>
<chapter>
<title>System Operation</title>
data later...
</para>
<para>
- We don't generally use a 'normal packet radio' mode like APRS because they're
- just too inefficient. The GFSK modulation we use is FSK with the
- base-band pulses passed through a
- Gaussian filter before they go into the modulator to limit the
- transmitted bandwidth. When combined with the hardware forward error
- correction support in the cc1111 chip, this allows us to have a very
- robust 38.4 kilobit data link with only 10 milliwatts of transmit
- power, a whip antenna in the rocket, and a hand-held Yagi on the
- ground. We've had flights to above 21k feet AGL with great reception,
- and calculations suggest we should be good to well over 40k feet AGL
- with a 5-element yagi on the ground. We hope to fly boards to higher
- altitudes over time, and would of course appreciate customer feedback
- on performance in higher altitude flights!
- </para>
- <para>
- However, TeleMetrum v2.0 and TeleMega can send APRS if
- desired, the interval between APRS packets can be
- configured. As each APRS packet takes a full second to
- transmit, we recommend an interval of at least 5 seconds.
+ We don't generally use a 'normal packet radio' mode like APRS
+ because they're just too inefficient. The GFSK modulation we
+ use is FSK with the base-band pulses passed through a Gaussian
+ filter before they go into the modulator to limit the
+ transmitted bandwidth. When combined with forward error
+ correction and interleaving, this allows us to have a very
+ robust 19.2 kilobit data link with only 10-40 milliwatts of
+ transmit power, a whip antenna in the rocket, and a hand-held
+ Yagi on the ground. We've had flights to above 21k feet AGL
+ with great reception, and calculations suggest we should be
+ good to well over 40k feet AGL with a 5-element yagi on the
+ ground with our 10mW units and over 100k feet AGL with the
+ 40mW devices. We hope to fly boards to higher altitudes over
+ time, and would of course appreciate customer feedback on
+ performance in higher altitude flights!
+ </para>
+ <para>
+ TeleMetrum v2.0 and TeleMega can send APRS if desired, the
+ interval between APRS packets can be configured. As each APRS
+ packet takes a full second to transmit, we recommend an
+ interval of at least 5 seconds to avoid consuming too much
+ battery power or radio channel bandwidth.
</para>
</section>
<section>
<section>
<title>Maximum Flight Log</title>
<para>
- TeleMetrum version 1.1 and 1.2 have 2MB of on-board flash storage,
- enough to hold over 40 minutes of data at full data rate
- (100 samples/second). TeleMetrum 1.0 has 1MB of on-board
- storage. As data are stored at a reduced rate during descent
- (10 samples/second), there's plenty of space to store many
- flights worth of data.
- </para>
- <para>
- TeleMetrum v2.0 and TeleMega have 8MB of on-board flash stroage, enough to hold
+ Each flight computer logs data at 100 samples per second
+ during ascent and 10 samples per second during descent. Data
+ are logged to an on-board flash memory part, which can be
+ partitioned into several equal-sized blocks, one for each
+ flight.
</para>
+ <table frame='all'>
+ <title>Data Storage on Altus Metrum altimeters</title>
+ <tgroup cols='4' align='center' colsep='1' rowsep='1'>
+ <colspec align='center' colwidth='*' colname='Device'/>
+ <colspec align='center' colwidth='*' colname='Bytes per sample'/>
+ <colspec align='center' colwidth='*' colname='Total storage'/>
+ <colspec align='center' colwidth='*' colname='Minutes of
+ full-rate'/>
+ <thead>
+ <row>
+ <entry align='center'>Device</entry>
+ <entry align='center'>Bytes per Sample</entry>
+ <entry align='center'>Total Storage</entry>
+ <entry align='center'>Minutes at Full Rate</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>TeleMetrum v1.x</entry>
+ <entry>8</entry>
+ <entry>2MB</entry>
+ <entry>40</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
<para>
The on-board flash is partitioned into separate flight logs,
each of a fixed maximum size. Increase the maximum size of
flights.
</para>
<para>
- All of the configuration data is also stored in the flash
- memory, which consumes 64kB on TeleMetrum v1.1/v1.2 and 256B on
- TeleMetrum v1.0. This configuration space is not available
- for storing flight log data.
+ Configuration data is also stored in the flash memory on
+ TeleMetrum v1.x, TeleMini and EasyMini. This consumes 64kB
+ of flash space. This configuration space is not available
+ for storing flight log data. TeleMetrum v2.0 and TeleMega
+ store configuration data in a bit of eeprom available within
+ the processor chip.
</para>
<para>
To compute the amount of space needed for a single flight,
you can multiply the expected ascent time (in seconds) by
- 800, multiply the expected descent time (in seconds) by 80
- and add the two together. That will slightly under-estimate
- the storage (in bytes) needed for the flight. For instance,
- a flight spending 20 seconds in ascent and 150 seconds in
- descent will take about (20 * 800) + (150 * 80) = 28000
- bytes of storage. You could store dozens of these flights in
- the on-board flash.
+ 100 times bytes-per-sample (8 for TeleMetrum v1.x, 16 for
+ TeleMetrum v2.0 and 32 for TeleMega), multiply the expected
+ descent time (in seconds) by 80 and add the two
+ together. That will slightly under-estimate the storage (in
+ bytes) needed for the flight. For instance, a flight
+ spending 20 seconds in ascent and 150 seconds in descent
+ will take about (20 * 800) + (150 * 80) = 28000 bytes of
+ storage. You could store dozens of these flights in the
+ on-board flash.
</para>
<para>
The default size, 192kB, allows for 10 flights of storage on
a fixed height above the ground, you can configure the
altimeter to fire both at apogee or both during
descent. This was added to support an airframe that has two
- TeleMetrum computers, one in the fin can and one in the
+ altimeters, one in the fin can and one in the
nose.
</para>
<para>
<section>
<title>Pad Orientation</title>
<para>
- TeleMetrum measures acceleration along the axis of the
- board. Which way the board is oriented affects the sign of
- the acceleration value. Instead of trying to guess which way
- the board is mounted in the air frame, TeleMetrum must be
- explicitly configured for either Antenna Up or Antenna
- Down. The default, Antenna Up, expects the end of the
- TeleMetrum board connected to the 70cm antenna to be nearest
- the nose of the rocket, with the end containing the screw
+ TeleMetrum and TeleMega measure acceleration along the axis
+ of the board. Which way the board is oriented affects the
+ sign of the acceleration value. Instead of trying to guess
+ which way the board is mounted in the air frame, the
+ altimeter must be explicitly configured for either Antenna
+ Up or Antenna Down. The default, Antenna Up, expects the end
+ of the board connected to the 70cm antenna to be nearest the
+ nose of the rocket, with the end containing the screw
terminals nearest the tail.
</para>
</section>
+ <section>
+ <title>Pyro Channels</title>
+ <para>
+ TeleMega
+ </para>
+ </section>
</section>
</chapter>
projects / fw / altos / blobdiff