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[Firebug-cvs] firebug/web gps_driver.html,1.4,1.5
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From: <cs...@us...> - 2003-06-09 17:45:49
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Update of /cvsroot/firebug/firebug/web
In directory sc8-pr-cvs1:/tmp/cvs-serv2212
Modified Files:
gps_driver.html
Log Message:
added topo links to gps_driver
Index: gps_driver.html
===================================================================
RCS file: /cvsroot/firebug/firebug/web/gps_driver.html,v
retrieving revision 1.4
retrieving revision 1.5
diff -C2 -d -r1.4 -r1.5
*** gps_driver.html 23 May 2003 15:15:21 -0000 1.4
--- gps_driver.html 9 Jun 2003 17:45:46 -0000 1.5
***************
*** 13,64 ****
</head>
!
!
! <body>
<h1>FireBug --- GPS Driver</h1>
! <p> FireBug uses the <tt>gps</tt> driver to interface with a GPS
! receiver and handle location information. </p>
<h2>Introduction</h2>
! <p> The current driver implements standard NMEA protocol to interact
! with an AXIOM GPS receiver. Running <tt>gpsM.nc</tt> on the client
! mote initializes the receiver for GPS Fix Data (GGA) reception. Incoming
! GGA data is checked by the client for validity, parsed, and then stored
! in its EEPROM flash memory. </p>
<h2>How <tt>gps</tt> works</h2>
! <p> GPS receivers provide location and time information in a variety
! of data formats. At initialization, the client's UART is set to
! the same baud rate as the GPS receiver. Next, <tt>clearGPS()</tt> is
! called, which commands the receiver to block all output. The receiver
! requires several seconds before it can start processing NMEA commands
! following power on. For this reason, the first command in <tt>clearGPS()</tt>
! is sent 100 times until the receiver has warmed up.</p>
! <p>For this application, a single GGA message is required. To acquire this,
! <tt>getGPS()</tt> is called, which requests GGA data at 1 Hz. The
! number of satellites used in constructing each GGA message is then determined.
! When this number exceeds three, the corresponding message is parsed
! and stored in the client's EEPROM.</p>
! <p> Values stored in the client's memory can the be retrieved and broadcasted
! over the radio at any time with <tt>GenericBase</tt>. Instructions
! on this are given at the end of this guide. </p>
<h2>Sending Commands to the Receiver</h2>
<p> Communication between the client and receiver is handled by <tt>
! gpsM.nc</tt>. After the client's second UART (UART1) is
! set to 4800 baud, NMEA commands may be sent to the gps receiver. For
! SiRF chips, these generally have the form:</p>
<center>
<p>$PSRF,103,<b>Message type</b>,00,<b>Rate</b>,01,*<b>Checksum</b></p>
</center>
! <p>followed by a carriage return ('\r') and linefeed ('\n'). There are six
! message types: </p>
<center>
<p>GGA=00, GLL=01, GSA=02, GSV=03, RMC=04, VTG=05</p>
</center>
! <p> To block output of a certain message type, set Rate = 00. Rate = 01
! corresponds to a 1 Hz output. Finally, the checksum is computed by performing
! an XOR on all characters, including the comma delimiters, between $ and *.
! Each character of the above string is contained as an element in the array
! <tt> cmd_msg</tt>, which is used throughout <tt>gpsM.nc</tt>. By changing
! array entries, different commands can be sent to the receiver, as shown
! below:</p>
<center>
<table class="code">
--- 13,63 ----
</head>
! <body>
<h1>FireBug --- GPS Driver</h1>
! <p> FireBug uses the <tt>gps</tt> driver to interface with a GPS receiver
! and handle location information. </p>
<h2>Introduction</h2>
! <p> The current driver implements standard NMEA protocol to interact
! with an AXIOM GPS receiver. Running <tt>gpsM.nc</tt> on the
! client mote initializes the receiver for GPS Fix Data (GGA) reception.
! Incoming GGA data is checked by the client for validity, parsed,
! and then stored in its EEPROM flash memory. </p>
<h2>How <tt>gps</tt> works</h2>
! <p> GPS receivers provide location and time information in a variety
! of data formats. At initialization, the client's UART is set
! to the same baud rate as the GPS receiver. Next, <tt>clearGPS()</tt>
! is called, which commands the receiver to block all output.
! The receiver requires several seconds before it can start processing
! NMEA commands following power on. For this reason, the first command
! in <tt>clearGPS()</tt> is sent 100 times until the receiver has
! warmed up.</p>
! <p>For this application, a single GGA message is required. To acquire this,
! <tt>getGPS()</tt> is called, which requests GGA data at 1 Hz.
! The number of satellites used in constructing each GGA message
! is then determined. When this number exceeds three, the corresponding
! message is parsed and stored in the client's EEPROM.</p>
! <p> Values stored in the client's memory can the be retrieved and broadcasted
! over the radio at any time with <tt>GenericBase</tt>. Instructions
! on this are given at the end of this guide. </p>
<h2>Sending Commands to the Receiver</h2>
<p> Communication between the client and receiver is handled by <tt>
! gpsM.nc</tt>. After the client's second UART
! (UART1) is set to 4800 baud, NMEA commands may be sent to the gps
! receiver. For SiRF chips, these generally have the form:</p>
<center>
<p>$PSRF,103,<b>Message type</b>,00,<b>Rate</b>,01,*<b>Checksum</b></p>
</center>
! <p>followed by a carriage return ('\r') and linefeed ('\n'). There are six
! message types: </p>
<center>
<p>GGA=00, GLL=01, GSA=02, GSV=03, RMC=04, VTG=05</p>
</center>
! <p> To block output of a certain message type, set Rate = 00. Rate = 01 corresponds
! to a 1 Hz output. Finally, the checksum is computed by performing an XOR
! on all characters, including the comma delimiters, between $ and *. Each
! character of the above string is contained as an element in the array <tt>
! cmd_msg</tt>, which is used throughout <tt>gpsM.nc</tt>. By changing
! array entries, different commands can be sent to the receiver, as shown
! below:</p>
<center>
<table class="code">
***************
*** 73,92 ****
</center>
<p>Here, the command outb(UDR1,cmd_msg[i]) sends the byte at entry <i>i</i>
! of <tt>cmd_msg</tt> out to UART1. </p>
<h2>Receiving Data from GPS Module</h2>
! <p>Data enters into the client from the receiver via UART1. Messages from
! the receiver are collected byte by byte with the command <tt>inp(UDR1)</tt>
! and temporarily stored in an array, <tt>rxBuffer</tt>. Data is
! collected only after the GGA start sequence, <tt>$GPGGA</tt>, is completed.
! Collection stops when the * delimiter is reached, after which point,
! the 40th and 41st entries of the buffer are combined to determine the number
! of satellites, i.e.</p>
<center>
<p>num_satellites = 10*(rxBuffer[40] - '0') + (rxBuffer[41] - '0');</p>
</center>
! <p>If <tt>num_satellite</tt> < 4, <tt>rxBuffer</tt> is cleared and the
! client waits again for the GGA start sequence to pass in the subsequent
! message until it resumes data collection. Otherwise, the data stored in
! the buffer is parsed and stored in EEPRROM using <tt>logGPS</tt>.</p>
<center>
<table class="code">
--- 72,92 ----
</center>
<p>Here, the command outb(UDR1,cmd_msg[i]) sends the byte at entry <i>i</i>
! of <tt>cmd_msg</tt> out to UART1. </p>
<h2>Receiving Data from GPS Module</h2>
! <p>Data enters into the client from the receiver via UART1. Messages from
! the receiver are collected byte by byte with the command <tt>inp(UDR1)</tt>
! and temporarily stored in an array, <tt>rxBuffer</tt>.
! Data is collected only after the GGA start sequence, <tt>$GPGGA</tt>
! , is completed. Collection stops when the * delimiter is reached,
! after which point, the 40th and 41st entries of the buffer are combined
! to determine the number of satellites, i.e.</p>
<center>
<p>num_satellites = 10*(rxBuffer[40] - '0') + (rxBuffer[41] - '0');</p>
</center>
! <p>If <tt>num_satellite</tt> < 4, <tt>rxBuffer</tt> is cleared and the
! client waits again for the GGA start sequence to pass in the subsequent
! message until it resumes data collection. Otherwise, the data stored
! in the buffer is parsed and stored in EEPRROM using <tt>logGPS</tt>
! .</p>
<center>
<table class="code">
***************
*** 101,108 ****
</center>
<h2>Logging and Retrieving Data</h2>
! <p>Fields in the GGA message are comma delimited. These are parsed with <tt>
! logGPS()</tt>, which simultaneously stores the data into the client's EEPROM
! using <tt>LoggerWrite.write</tt>. One line of memory is reserved for each
! field, and these are numbered as follows:<br>
<br>
</p>
--- 101,108 ----
</center>
<h2>Logging and Retrieving Data</h2>
! <p>Fields in the GGA message are comma delimited. These are parsed with
! <tt> logGPS()</tt>, which simultaneously stores the data into the
! client's EEPROM using <tt>LoggerWrite.write</tt>. One line of memory
! is reserved for each field, and these are numbered as follows:<br>
<br>
</p>
***************
*** 193,211 ****
</table>
</center>
! <p> To retrieve data, load a second mote with <code>GenericBase</code> and
! perform the following: </p>
<ol>
<li>Leaving the GenericBase mote connected to the programming board,
start the serial port forwarding service using the command
<code>java net.tinyos.sf.SerialForward</code></li>
! <li>Broadcast retrieve command over the radio: <code>java net.tinyos.tools.gpsBcast
! <group ID> <b>Field Name</b> <gps mote
! ID></code></li>
! <li>Packet is sent to the base station via radio. Contained in the packet
! payload is the data for the selected field. </li>
</ol>
<hr /="">
! <p> Last updated: $Date$ by $Author$.
! </p>
</body>
</html>
--- 193,239 ----
</table>
</center>
! <p> To retrieve data, load a second mote with <code>GenericBase</code> and
! perform the following: </p>
<ol>
<li>Leaving the GenericBase mote connected to the programming board,
start the serial port forwarding service using the command
<code>java net.tinyos.sf.SerialForward</code></li>
! <li>Broadcast retrieve command over the radio: <code>java net.tinyos.tools.gpsBcast
! <group ID> <b>Field Name</b> <gps
! mote ID></code></li>
! <li>Packet is sent to the base station via radio. Contained in the packet
! payload is the data for the selected field. </li>
! </ol>
! <h2>Instructions for Use</h2>
! <p>NOTE: gps.nc only runs on the mica2 platform</p>
! <ol>
! <li>Load gps into mica2</li>
! <li>Mica2 will take several minutes to lock on to satellites</li>
! <li>Load a second mote with GenericBase</li>
! <li>Leaving the GenericBase mote connected to the programming board,
! start the serial port forwarding service using the command <br>
! <center><code>java net.tinyos.sf.SerialForward</code></center>
! </li>
! <li>Run gpsBcast to have gps data sent to the GenericBase mote (base station)
! over the radio. From the <tt>firebug/project/java</tt> directory, type
! <br>
! <center><code>./gpsrun.sh <group ID> <b>Field Name</b>
! <gps mote ID></code></center>
! </li>
! <li>Packet is sent to the base station via radio. Contained in the packet
! payload is the data for the selected field.</li>
</ol>
+ Alternatively, the gps driver can be connected directly to the PC via the
+ programming board. GPS data could be sent to UART and displayed on
+ the PC with a java application. .<br>
+ <h2>Useful Links</h2>
+ <p><a href="http://nmviewogc.cr.usgs.gov/viewer">USGS National Map Viewer</a>
+ -- use <i>Identify</i> tool to get Long/Lat coordinates of any point in
+ the U.S.A.</p>
+ <p><a href="http://www.topozone.com">www.topozone.com</a>
+ -- interactive USGS topo map of the entire U.S.A.</p>
<hr /="">
! <p> Last updated: $Date$ by $Author$.
! </p>
</body>
</html>
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