<?xml version="1.0" encoding="utf-8" ?>
-<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
+<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"/usr/share/xml/docbook/schema/dtd/4.5/docbookx.dtd">
<article>
</revision>
</revhistory>
</articleinfo>
- <section>
- <title>History and Motivation</title>
- <para>
- The original AltoOS telemetry mechanism encoded everything
- available piece of information on the TeleMetrum hardware into a
- single unified packet. Initially, the packets contained very
- little data—some raw sensor readings along with the current GPS
- coordinates when a GPS receiver was connected. Over time, the
- amount of data grew to include sensor calibration data, GPS
- satellite information and a host of internal state information
- designed to help diagnose flight failures in case of a loss of
- the on-board flight data.
- </para>
- <para>
- Because every packet contained all of the data, packets were
- huge—95 bytes long. Much of the information was also specific to
- the TeleMetrum hardware. With the introduction of the TeleMini
- flight computer, most of the data contained in the telemetry
- packets was unavailable. Initially, a shorter, but still
- comprehensive packet was implemented. This required that the
- ground station be pre-configured as to which kind of packet to
- expect.
- </para>
- <para>
- The development of several companion boards also made the
- shortcomings evident—each companion board would want to include
- telemetry data in the radio link; with the original design, the
- packet would have to hold the new data as well, requiring
- additional TeleMetrum and ground station changes.
- </para>
- </section>
<section>
<title>Packet Format Design</title>
<para>
</section>
<section>
<title>Packet Formats</title>
- This section first defines the packet header common to all packets
- and then the per-packet data layout.
+ <para>
+ This section first defines the packet header common to all packets
+ and then the per-packet data layout.
+ </para>
<section>
<title>Packet Header</title>
<table frame='all'>
<title>Telemetry Packet Header</title>
<tgroup cols='4' align='center' colsep='1' rowsep='1'>
- <colspec align='right' colwidth='*' colname='Offset'/>
+ <colspec align='center' colwidth='*' colname='Offset'/>
<colspec align='center' colwidth='3*' colname='Data Type'/>
<colspec align='left' colwidth='3*' colname='Name'/>
<colspec align='left' colwidth='9*' colname='Description'/>
that the receiver knows which data values are valid and which
are undefined.
</para>
+ <para>
+ Sensor Data packets are transmitted once per second on the
+ ground, 10 times per second during ascent and once per second
+ during descent and landing
+ </para>
<table frame='all'>
<title>Sensor Packet Contents</title>
<tgroup cols='4' align='center' colsep='1' rowsep='1'>
- <colspec align='right' colwidth='*' colname='Offset'/>
+ <colspec align='center' colwidth='*' colname='Offset'/>
<colspec align='center' colwidth='3*' colname='Data Type'/>
<colspec align='left' colwidth='3*' colname='Name'/>
<colspec align='left' colwidth='9*' colname='Description'/>
<entry>16</entry><entry>int16_t</entry><entry>sense_m</entry><entry>main continuity sense (TM/Tm)</entry>
</row>
<row>
- <entry>18</entry><entry>int16_t</entry><entry>accel</entry><entry>m/s² * 16</entry>
+ <entry>18</entry><entry>int16_t</entry><entry>acceleration</entry><entry>m/s² * 16</entry>
</row>
<row>
<entry>20</entry><entry>int16_t</entry><entry>speed</entry><entry>m/s * 16</entry>
<entry>22</entry><entry>int16_t</entry><entry>height</entry><entry>m</entry>
</row>
<row>
- <entry>24</entry><entry>int16_t</entry><entry>ground_accel</entry><entry>TM</entry>
+ <entry>24</entry><entry>int16_t</entry><entry>ground_pres</entry><entry>Average barometer reading on ground</entry>
</row>
<row>
- <entry>26</entry><entry>int16_t</entry><entry>ground_pres</entry><entry>Average barometer reading on ground</entry>
+ <entry>26</entry><entry>int16_t</entry><entry>ground_accel</entry><entry>TM</entry>
</row>
<row>
<entry>28</entry><entry>int16_t</entry><entry>accel_plus_g</entry><entry>TM</entry>
</tbody>
</tgroup>
</informaltable>
+ <para>
+ This provides a description of the software installed on the
+ flight computer as well as any user-specified configuration data.
+ </para>
+ <para>
+ Configuration data packets are transmitted once per second
+ during all phases of the flight
+ </para>
<table frame='all'>
<title>Sensor Packet Contents</title>
<tgroup cols='4' align='center' colsep='1' rowsep='1'>
- <colspec align='right' colwidth='*' colname='Offset'/>
+ <colspec align='center' colwidth='*' colname='Offset'/>
<colspec align='center' colwidth='3*' colname='Data Type'/>
<colspec align='left' colwidth='3*' colname='Name'/>
<colspec align='left' colwidth='9*' colname='Description'/>
<entry>9</entry><entry>uint8_t</entry><entry>config_minor</entry><entry>Config minor version</entry>
</row>
<row>
- <entry>10</entry><entry>uint16_t</entry><entry>main_deploy</entry><entry>Main deploy alt in meters</entry>
+ <entry>10</entry><entry>uint16_t</entry><entry>apogee_delay</entry>
+ <entry>Apogee deploy delay in seconds</entry>
</row>
<row>
- <entry>12</entry><entry>uint32_t</entry><entry>flight_log_max</entry><entry>Maximum flight log size (B)</entry>
+ <entry>12</entry><entry>uint16_t</entry><entry>main_deploy</entry><entry>Main deploy alt in meters</entry>
+ </row>
+ <row>
+ <entry>14</entry><entry>uint16_t</entry><entry>flight_log_max</entry>
+ <entry>Maximum flight log size (kB)</entry>
</row>
<row>
<entry>16</entry><entry>char</entry><entry>callsign[8]</entry><entry>Radio operator identifier</entry>
</tbody>
</tgroup>
</informaltable>
+ <para>
+ This packet provides all of the information available from the
+ Venus SkyTraq GPS receiver—position, time, speed and precision
+ estimates.
+ </para>
+ <para>
+ GPS Location packets are transmitted once per second during
+ all phases of the flight
+ </para>
<table frame='all'>
<title>GPS Location Packet Contents</title>
<tgroup cols='4' align='center' colsep='1' rowsep='1'>
- <colspec align='right' colwidth='*' colname='Offset'/>
+ <colspec align='center' colwidth='*' colname='Offset'/>
<colspec align='center' colwidth='3*' colname='Data Type'/>
<colspec align='left' colwidth='3*' colname='Name'/>
<colspec align='left' colwidth='9*' colname='Description'/>
</thead>
<tbody>
<row>
- <entry>5</entry><entry>uint8_t</entry><entry>flags</entry><entry>GPS Flags (see below)</entry>
+ <entry>5</entry><entry>uint8_t</entry><entry>flags</entry>
+ <entry>See GPS Flags table below</entry>
</row>
<row>
<entry>6</entry><entry>int16_t</entry><entry>altitude</entry><entry>m</entry>
<entry>24</entry><entry>uint8_t</entry><entry>vdop</entry><entry>* 5</entry>
</row>
<row>
- <entry>25</entry><entry>uint8_t</entry><entry>mode</entry><entry>N, A, D, E, M, S</entry>
+ <entry>25</entry><entry>uint8_t</entry><entry>mode</entry>
+ <entry>See GPS Mode table below</entry>
</row>
<row>
<entry>26</entry><entry>uint16_t</entry><entry>ground_speed</entry><entry>cm/s</entry>
</row>
<row>
- <entry>28</entry><entry>uint8_t</entry><entry>course</entry><entry>/ 2</entry>
+ <entry>28</entry><entry>int16_t</entry><entry>climb_rate</entry><entry>cm/s</entry>
</row>
<row>
- <entry>29</entry><entry>uint8_t</entry><entry>unused[2]</entry>
+ <entry>30</entry><entry>uint8_t</entry><entry>course</entry><entry>/ 2</entry>
+ </row>
+ <row>
+ <entry>31</entry><entry>uint8_t</entry><entry>unused[1]</entry>
</row>
<row>
<entry>32</entry>
</tbody>
</tgroup>
</table>
+ <para>
+ Packed into a one byte field are status flags and the count of
+ satellites used to compute the position fix. Note that this
+ number may be lower than the number of satellites being
+ tracked; the receiver will not use information from satellites
+ with weak signals or which are close enough to the horizon to
+ have significantly degraded position accuracy.
+ </para>
+ <table frame='all'>
+ <title>GPS Flags</title>
+ <tgroup cols='3' colsep='1' rowsep='1'>
+ <colspec align='center' colwidth='*' colname='bits'/>
+ <colspec align='left' colwidth='2*' colname='name'/>
+ <colspec align='left' colwidth='7*' colname='description'/>
+ <thead>
+ <row>
+ <entry align='center'>Bits</entry>
+ <entry align='center'>Name</entry>
+ <entry align='center'>Description</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>0-3</entry>
+ <entry>nsats</entry>
+ <entry>Number of satellites in solution</entry>
+ </row>
+ <row>
+ <entry>4</entry>
+ <entry>valid</entry>
+ <entry>GPS solution is valid</entry>
+ </row>
+ <row>
+ <entry>5</entry>
+ <entry>running</entry>
+ <entry>GPS receiver is operational</entry>
+ </row>
+ <row>
+ <entry>6</entry>
+ <entry>date_valid</entry>
+ <entry>Reported date is valid</entry>
+ </row>
+ <row>
+ <entry>7</entry>
+ <entry>course_valid</entry>
+ <entry>ground speed, course and climb rates are valid</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <para>
+ Here are all of the valid GPS operational modes. Altus Metrum
+ products will only ever report 'N' (not valid), 'A'
+ (Autonomous) modes or 'E' (Estimated). The remaining modes
+ are either testing modes or require additional data.
+ </para>
+ <table frame='all'>
+ <title>GPS Mode</title>
+ <tgroup cols='3' colsep='1' rowsep='1'>
+ <colspec align='center' colwidth='*' colname='value'/>
+ <colspec align='center' colwidth='3*' colname='name'/>
+ <colspec align='left' colwidth='7*' colname='description'/>
+ <thead>
+ <row>
+ <entry align='center'>Mode</entry>
+ <entry align='center'>Name</entry>
+ <entry align='center'>Decsription</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>N</entry>
+ <entry>Not Valid</entry>
+ <entry>All data are invalid</entry>
+ </row>
+ <row>
+ <entry>A</entry>
+ <entry>Autonomous mode</entry>
+ <entry>Data are derived from satellite data</entry>
+ </row>
+ <row>
+ <entry>D</entry>
+ <entry>Differential Mode</entry>
+ <entry>
+ Data are augmented with differential data from a
+ known ground station. The SkyTraq unit in TeleMetrum
+ does not support this mode
+ </entry>
+ </row>
+ <row>
+ <entry>E</entry>
+ <entry>Estimated</entry>
+ <entry>
+ Data are estimated using dead reckoning from the
+ last known data
+ </entry>
+ </row>
+ <row>
+ <entry>M</entry>
+ <entry>Manual</entry>
+ <entry>Data were entered manually</entry>
+ </row>
+ <row>
+ <entry>S</entry>
+ <entry>Simulated</entry>
+ <entry>GPS receiver testing mode</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
</section>
<section>
<title>GPS Satellite Data</title>
</tbody>
</tgroup>
</informaltable>
+ <para>
+ This packet provides space vehicle identifiers and signal
+ quality information in the form of a C/N1 number for up to 12
+ satellites. The order of the svids is not specified.
+ </para>
+ <para>
+ GPS Satellite data are transmitted once per second during all
+ phases of the flight.
+ </para>
<table frame='all'>
<title>GPS Satellite Data Contents</title>
<tgroup cols='4' align='center' colsep='1' rowsep='1'>
<tbody>
<row>
<entry>5</entry><entry>uint8_t</entry><entry>channels</entry>
+ <entry>Number of reported satellite information</entry>
</row>
<row>
- <entry>6</entry><entry>uint8_t</entry><entry>sat_0_id</entry>
+ <entry>6</entry><entry>sat_info_t</entry><entry>sats[12]</entry>
+ <entry>See Per-Satellite data table below</entry>
</row>
<row>
- <entry>7</entry><entry>uint8_t</entry><entry>sat_0_c_n_1</entry>
+ <entry>30</entry><entry>uint8_t</entry><entry>unused[2]</entry>
</row>
<row>
- <entry>8</entry><entry>uint8_t</entry><entry>sat_1_id</entry>
- </row>
- <row>
- <entry>9</entry><entry>uint8_t</entry><entry>sat_1_c_n_1</entry>
- </row>
- <row>
- <entry>10</entry><entry>uint8_t</entry><entry>sat_2_id</entry>
- </row>
- <row>
- <entry>11</entry><entry>uint8_t</entry><entry>sat_2_c_n_1</entry>
- </row>
- <row>
- <entry>12</entry><entry>uint8_t</entry><entry>sat_3_id</entry>
- </row>
- <row>
- <entry>13</entry><entry>uint8_t</entry><entry>sat_3_c_n_1</entry>
- </row>
- <row>
- <entry>14</entry><entry>uint8_t</entry><entry>sat_4_id</entry>
- </row>
- <row>
- <entry>15</entry><entry>uint8_t</entry><entry>sat_4_c_n_1</entry>
- </row>
- <row>
- <entry>16</entry><entry>uint8_t</entry><entry>sat_5_id</entry>
- </row>
- <row>
- <entry>17</entry><entry>uint8_t</entry><entry>sat_5_c_n_1</entry>
- </row>
- <row>
- <entry>18</entry><entry>uint8_t</entry><entry>sat_6_id</entry>
+ <entry>32</entry>
</row>
+ </tbody>
+ </tgroup>
+ </table>
+ <table frame='all'>
+ <title>GPS Per-Satellite data (sat_info_t)</title>
+ <tgroup cols='4' align='center' colsep='1' rowsep='1'>
+ <colspec align='right' colwidth='*' colname='Offset'/>
+ <colspec align='center' colwidth='3*' colname='Data Type'/>
+ <colspec align='left' colwidth='3*' colname='Name'/>
+ <colspec align='left' colwidth='9*' colname='Description'/>
+ <thead>
<row>
- <entry>19</entry><entry>uint8_t</entry><entry>sat_6_c_n_1</entry>
+ <entry align='center'>Offset</entry>
+ <entry align='center'>Data Type</entry>
+ <entry align='center'>Name</entry>
+ <entry align='center'>Description</entry>
</row>
+ </thead>
+ <tbody>
<row>
- <entry>20</entry><entry>uint8_t</entry><entry>sat_7_id</entry>
+ <entry>0</entry><entry>uint8_t</entry><entry>svid</entry>
+ <entry>Space Vehicle Identifier</entry>
</row>
<row>
- <entry>21</entry><entry>uint8_t</entry><entry>sat_7_c_n_1</entry>
+ <entry>1</entry><entry>uint8_t</entry><entry>c_n_1</entry>
+ <entry>C/N1 signal quality indicator</entry>
</row>
<row>
- <entry>22</entry><entry>uint8_t</entry><entry>sat_8_id</entry>
+ <entry>2</entry>
</row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ </section>
+ <section>
+ <title>Data Transmission</title>
+ <para>
+ Altus Metrum devices use the Texas Instruments CC1111
+ microcontroller which includes an integrated sub-GHz digital
+ transceiver. This transceiver is used to both transmit and
+ receive the telemetry packets. This section discusses what
+ modulation scheme is used and how this device is configured.
+ </para>
+ <section>
+ <title>Modulation Scheme</title>
+ <para>
+ Texas Instruments provides a tool for computing modulation
+ parameters given a desired modulation format and basic bit
+ rate. For AltOS, the basic bit rate was specified as 38 kBaud,
+ resulting in the following signal parmeters:
+ </para>
+ <table>
+ <title>Modulation Scheme</title>
+ <tgroup cols='3'>
+ <colspec align="center" colwidth="*" colname="parameter"/>
+ <colspec align="center" colwidth="*" colname="value"/>
+ <colspec align="center" colwidth="*" colname="description"/>
+ <thead>
<row>
- <entry>23</entry><entry>uint8_t</entry><entry>sat_8_c_n_1</entry>
+ <entry align='center'>Parameter</entry>
+ <entry align='center'>Value</entry>
+ <entry align='center'>Description</entry>
</row>
+ </thead>
+ <tbody>
<row>
- <entry>24</entry><entry>uint8_t</entry><entry>sat_9_id</entry>
+ <entry>Modulation</entry>
+ <entry>GFSK</entry>
+ <entry>Gaussian Frequency Shift Keying</entry>
</row>
<row>
- <entry>25</entry><entry>uint8_t</entry><entry>sat_9_c_n_1</entry>
+ <entry>Deviation</entry>
+ <entry>20.507812 kHz</entry>
+ <entry>Frequency modulation</entry>
</row>
<row>
- <entry>26</entry><entry>uint8_t</entry><entry>sat_10_id</entry>
+ <entry>Data rate</entry>
+ <entry>38.360596 kBaud</entry>
+ <entry>Raw bit rate</entry>
</row>
<row>
- <entry>27</entry><entry>uint8_t</entry><entry>sat_10_c_n_1</entry>
+ <entry>RX Filter Bandwidth</entry>
+ <entry>93.75 kHz</entry>
+ <entry>Receiver Band pass filter bandwidth</entry>
</row>
<row>
- <entry>28</entry><entry>uint8_t</entry><entry>sat_11_id</entry>
+ <entry>IF Frequency</entry>
+ <entry>140.62 kHz</entry>
+ <entry>Receiver intermediate frequency</entry>
</row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section>
+ <title>Error Correction</title>
+ <para>
+ The cc1111 provides forward error correction in hardware,
+ which AltOS uses to improve reception of weak signals. The
+ overall effect of this is to halve the available bandwidth for
+ data from 38 kBaud to 19 kBaud.
+ </para>
+ <table>
+ <title>Error Correction</title>
+ <tgroup cols='3'>
+ <colspec align="center" colwidth="*" colname="parameter"/>
+ <colspec align="center" colwidth="*" colname="value"/>
+ <colspec align="center" colwidth="*" colname="description"/>
+ <thead>
<row>
- <entry>29</entry><entry>uint8_t</entry><entry>sat_11_c_n_1</entry>
+ <entry align='center'>Parameter</entry>
+ <entry align='center'>Value</entry>
+ <entry align='center'>Description</entry>
</row>
+ </thead>
+ <tbody>
<row>
- <entry>30</entry><entry>uin8_t</entry><entry>unused30</entry>
+ <entry>Error Correction</entry>
+ <entry>Convolutional coding</entry>
+ <entry>1/2 rate, constraint length m=4</entry>
</row>
<row>
- <entry>31</entry><entry>uin8_t</entry><entry>unused31</entry>
+ <entry>Interleaving</entry>
+ <entry>4 x 4</entry>
+ <entry>Reduce effect of noise burst</entry>
</row>
<row>
- <entry>32</entry>
+ <entry>Data Whitening</entry>
+ <entry>XOR with 9-bit PNR</entry>
+ <entry>Rotate right with bit 8 = bit 0 xor bit 5, initial
+ value 111111111</entry>
</row>
</tbody>
</tgroup>
</table>
</section>
</section>
+ <section>
+ <title>TeleDongle packet format</title>
+ <para>
+ TeleDongle does not do any interpretation of the packet data,
+ instead it is configured to receive packets of a specified
+ length (32 bytes in this case). For each received packet,
+ TeleDongle produces a single line of text. This line starts with
+ the string "TELEM " and is followed by a list of hexadecimal
+ encoded bytes.
+ </para>
+ <programlisting>TELEM 224f01080b05765e00701f1a1bbeb8d7b60b070605140c000600000000000000003fa988</programlisting>
+ <para>
+ The hexadecimal encoded string of bytes contains a length byte,
+ the packet data, two bytes added by the cc1111 radio receiver
+ hardware and finally a checksum so that the host software can
+ validate that the line was transmitted without any errors.
+ </para>
+ <table>
+ <title>Packet Format</title>
+ <tgroup cols='4'>
+ <colspec align="center" colwidth="2*" colname="offset"/>
+ <colspec align="center" colwidth="*" colname="name"/>
+ <colspec align="center" colwidth="*" colname="value"/>
+ <colspec align="center" colwidth="5*" colname="description"/>
+ <thead>
+ <row>
+ <entry align='center'>Offset</entry>
+ <entry align='center'>Name</entry>
+ <entry align='center'>Example</entry>
+ <entry align='center'>Description</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry>0</entry>
+ <entry>length</entry>
+ <entry>22</entry>
+ <entry>Total length of data bytes in the line. Note that
+ this includes the added RSSI and status bytes</entry>
+ </row>
+ <row>
+ <entry>1 ·· length-3</entry>
+ <entry>packet</entry>
+ <entry>4f ·· 00</entry>
+ <entry>Bytes of actual packet data</entry>
+ </row>
+ <row>
+ <entry>length-2</entry>
+ <entry>rssi</entry>
+ <entry>3f</entry>
+ <entry>Received signal strength. dBm = rssi / 2 - 74</entry>
+ </row>
+ <row>
+ <entry>length-1</entry>
+ <entry>lqi</entry>
+ <entry>a9</entry>
+ <entry>Link Quality Indicator and CRC status. Bit 7
+ is set when the CRC is correct</entry>
+ </row>
+ <row>
+ <entry>length</entry>
+ <entry>checksum</entry>
+ <entry>88</entry>
+ <entry>(0x5a + sum(bytes 1 ·· length-1)) % 256</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ </section>
+ <section>
+ <title>History and Motivation</title>
+ <para>
+ The original AltoOS telemetry mechanism encoded everything
+ available piece of information on the TeleMetrum hardware into a
+ single unified packet. Initially, the packets contained very
+ little data—some raw sensor readings along with the current GPS
+ coordinates when a GPS receiver was connected. Over time, the
+ amount of data grew to include sensor calibration data, GPS
+ satellite information and a host of internal state information
+ designed to help diagnose flight failures in case of a loss of
+ the on-board flight data.
+ </para>
+ <para>
+ Because every packet contained all of the data, packets were
+ huge—95 bytes long. Much of the information was also specific to
+ the TeleMetrum hardware. With the introduction of the TeleMini
+ flight computer, most of the data contained in the telemetry
+ packets was unavailable. Initially, a shorter, but still
+ comprehensive packet was implemented. This required that the
+ ground station be pre-configured as to which kind of packet to
+ expect.
+ </para>
+ <para>
+ The development of several companion boards also made the
+ shortcomings evident—each companion board would want to include
+ telemetry data in the radio link; with the original design, the
+ packet would have to hold the new data as well, requiring
+ additional TeleMetrum and ground station changes.
+ </para>
+ </section>
</article>
-
-<!--
-
-
-
-
- Rethinking this (over IRC), and thinking about telemetry from a
- companion board, it looks like 32 bytes per packet would be better (12
- channels of A/D from telescience would require 24 bytes).
-
- Packet type 0x06: GPS satellites
- 1 packet per second.
-
-
- TeleScience
-
-<entry>5</entry><entry>uint8_t</entry><entry>channels</entry>
-<entry>6</entry><entry>uint16_t</entry><entry>data[12]</entry>
-<entry>30</entry><entry>uint8_t</entry><entry>unused[2]</entry>
-<entry>32</entry>
-
- [ 2-line signature. Click/Enter to show. ]
- - -
- keith.packard@intel.com
- [ application/pgp-signature ]
- Keith Packard <keithp@keithp.com> (Mon. 18:59) (me sent)
- Subject: Re: New telemetry ideas
- To: bdale@gag.com
- Date: Mon, 27 Jun 2011 18:59:08 -0700
-
- [ multipart/signed ]
- [ text/plain ]
- On Mon, 27 Jun 2011 14:25:00 -0700, Keith Packard <keithp@keithp.com> wrote:
- Non-text part: multipart/signed
-
- > Packet type 0x05: GPS location
- > 1 packet per second
- >
- > 5 uint8_t flags
-
- Let's add another field here:
-
-<entry>6</entry><entry>int16_t</entry><entry>gps_tick</entry><entry>tick when GPS data was received</entry>
-
- That leaves a single byte unused
--->
\ No newline at end of file
projects / fw / altos / blobdiff