XBee radio communication between PICs - Revision history

MatthewElwin at 19:47, 4 August 2010

2010-08-04T19:47:24Z

LIMS: /* Results */

2009-07-07T16:21:33Z

Results

LIMS: /* Results */

2009-07-06T21:29:08Z

Results

LIMS: /* Experimental Setup */

2009-07-06T21:21:16Z

Experimental Setup

Hwang: /* Reading Packets with MATLAB in API Modes */

2009-04-21T07:15:29Z

Reading Packets with MATLAB in API Modes

Hwang: /* Reading Packets with MATLAB in API Modes= */

2009-04-21T07:14:27Z

Reading Packets with MATLAB in API Modes=

Hwang: /* Proprietary API mode */

2009-04-21T04:44:46Z

Proprietary API mode

Nelson Rosa: /* Results */

2009-01-30T00:44:28Z

Results

BrianB: Expanded "Commonly Used Commands" section

2009-01-07T00:07:08Z

Expanded "Commonly Used Commands" section

ScottM: /* Results */

2008-12-18T03:52:17Z

Results

@@ Line 475: / Line 475: @@
 </tr>
 </table>
+== Firmware Upgrade ==
+If you are trying to upgrade the firmware and are having problems, watch this video from digi:
+http://www.youtube.com/watch?v=fxOqQZD-oaM&feature=player_embedded
+(summary of video)
+. Unplug power, but keep serial cable connected.
+. Select the proper com port.
+.  Go to the modem configuration tab
+. Select the modem type (XB24), Function set and firmware version
+. Press Show defaults.
+. Press Write and wait for the an error box to display.
+. While holding the reset button, plug in the xbee.
+. The dialog box disappears and everything should be written.
+.  If you get an error, try hitting the write button again.

@@ Line 419: / Line 419: @@
 <p><font size="-1"><b>Round Trip Latency [for 100 byte packet] (ms)</b></font></p>
 </td>
-<td width="17.5%"><p><font size="-1"><b>Average RTT in Bps</b></font></p>
+<td width="17.5%"><p><font size="-1"><b>Average RTT in bps</b></font></p>
 </td>
 </tr>
@@ Line 430: / Line 430: @@
 </td>
 <td width="17.5%">
-<p><font size="-1">146.1</font></p>
+<p><font size="-1">1168.65</font></p>
 </td>
 </tr><tr>
@@ Line 440: / Line 440: @@
 </td>
 <td width="17.5%">
-<p><font size="-1">164.0</font></p>
+<p><font size="-1">1312.14</font></p>
 </td>
 </tr><tr>
@@ Line 450: / Line 450: @@
 </td>
 <td width="17.5%">
-<p><font size="-1">1039.7</font></p>
+<p><font size="-1">8317.61</font></p>
 </td>
 </tr><tr>
@@ Line 460: / Line 460: @@
 </td>
 <td width="17.5%">
-<p><font size="-1">40.8</font></p>
+<p><font size="-1">326.741</font></p>
 </td>
 </tr>
@@ Line 471: / Line 471: @@
 </td>
 <td width="17.5%">
-<p><font size="-1">630.95</font></p>
+<p><font size="-1">5047.62</font></p>
 </td>
 </tr>

@@ Line 417: / Line 417: @@
 </td>
 <td width="17.5%">
-<p><font size="-1"><b>Round Trip Latency (ms)</b></font></p>
+<p><font size="-1"><b>Round Trip Latency [for 100 byte packet] (ms)</b></font></p>
+</td>
+<td width="17.5%"><p><font size="-1"><b>Average RTT in Bps</b></font></p>
 </td>
 </tr>
@@ Line 425: / Line 427: @@
 </td>
 <td width="17.5%">
-<p><font size="-1">numbers coming soon!</font></p>
+<p><font size="-1">684.5</font></p>
+</td>
+<td width="17.5%">
+<p><font size="-1">146.1</font></p>
 </td>
 </tr><tr>
@@ Line 432: / Line 437: @@
 </td>
 <td width="17.5%">
-<p><font size="-1">numbers coming soon!</font></p>
+<p><font size="-1">609.7</font></p>
+</td>
+<td width="17.5%">
+<p><font size="-1">164.0</font></p>
 </td>
 </tr><tr>
@@ Line 439: / Line 447: @@
 </td>
 <td width="17.5%">
-<p><font size="-1">numbers coming soon!</font></p>
+<p><font size="-1">96.2</font></p>
+</td>
+<td width="17.5%">
+<p><font size="-1">1039.7</font></p>
 </td>
 </tr><tr>
@@ Line 446: / Line 457: @@
 </td>
 <td width="17.5%">
-<p><font size="-1">numbers coming soon!</font></p>
+<p><font size="-1">2448</font></p>
+</td>
+<td width="17.5%">
+<p><font size="-1">40.8</font></p>
 </td>
 </tr>
@@ Line 454: / Line 468: @@
 </td>
 <td width="17.5%">
-<p><font size="-1">numbers coming soon!</font></p>
+<p><font size="-1">158.5</font></p>
+</td>
+<td width="17.5%">
+<p><font size="-1">630.95</font></p>
 </td>
 </tr>

@@ Line 403: / Line 403: @@
 ===Experimental Setup===
-One XBee radio was connected to a computer running Windows XP with a standard USB->RS232 cable.  As programmed in Visual Studio C++ Express, the computer performed a "loopback" protocol; the computer wrote the data it received (to the serial port) upon the receipt of a byte (from the serial port).  In this sense, the computer simply echoes the data it receives on the serial port.
+One XBee radio was connected to a computer running Windows XP with a standard USB->RS232 cable.  As programmed in Visual Studio C++, the computer sent data in 100 byte packets, recording the amount of time it took to send and receive the entire packet.
-A second XBee radio was connected to a PIC184520 with a 40MHz crystal.  Using the PIC-C programming language, the XBee radio is controlled using the pic's hardware EUSART.  A variety of baud rates were tested as listed in the table below.
+A second XBee radio was connected to a PIC184520 with a 40MHz crystal.  Using the PIC-C programming language, the XBee radio is controlled using the pic's hardware EUSART. The PIC was programmed to echo each byte as it was received, so that the host PC would get a measurement of the combined send / receive time for the entire packet. A variety of baud rates were tested as listed in the table below.
-To capture the round trip time, the pic was programmed to set a digital output high, and send a byte of data.  Upon receipt of the data (from the loopbacked PC), the pic subsequently set the digital output low.  By viewing the digital output on an oscilloscope, the width of the pulse was measured to determine the amount of time between sending and receiving a single byte of data.
 *Note that the latency of the computer is included in this test.  For this test, it was assumed that the latency of the computer would be insignificant relative to the radios' communication time.  To remove this additional latency in the future, one should create a hardware loopback by powering the first Xbee radio and physically connecting this radio's Rx and Tx line via a wire (no computer or PIC needed).

@@ Line 309: / Line 309: @@
 ====Reading Packets with MATLAB in API Modes====
-You can read XBee API packets with MATLAB using the <tt>fread()</tt> function if you are using API Mode 1, if your packets are the same length.  When using <tt>fread()</tt>, you can specify how many bytes to read, and which data type the bytes should be interpreted as (integer, float, etc.).  However, when using API Mode 2, <tt>fread()</tt> becomes tricky to use because the escape characters will insert another byte into your packet.  One way around this is to read all the data as chars, process the escape characters, and then use the MEX function fourChar2Float to convert the chars into a 32-bit floating point number.
+You can read XBee API packets with MATLAB using the <tt>fread()</tt> function if you are using API Mode 1, if your packets are the same length.  When using <tt>fread()</tt>, you can specify how many bytes to read, and which data type the bytes should be interpreted as (integer, float, etc.).  However, when using API Mode 2, <tt>fread()</tt> becomes tricky to use because the escape characters will insert another byte into your packet.  One way around this is to read all the data as chars, process the escape characters, and then use the MEX function fourChar2Float to convert the chars into a 32-bit floating point number.  (See the comments in fourChar2Float.c for usage details).
 Download fourChar2Float here: [[Image:fourChar2Float.zip]]

@@ Line 308: / Line 308: @@
 Writing software for the API mode may be more difficult, as you have to assemble a packet and calculate a checksum.  You may wish to use API mode if you need to be able to detect corrupt data or if you need to communicate to many different radios individually.
-====Reading Packets with MATLAB in API Modes=====
+====Reading Packets with MATLAB in API Modes====
 You can read XBee API packets with MATLAB using the <tt>fread()</tt> function if you are using API Mode 1, if your packets are the same length.  When using <tt>fread()</tt>, you can specify how many bytes to read, and which data type the bytes should be interpreted as (integer, float, etc.).  However, when using API Mode 2, <tt>fread()</tt> becomes tricky to use because the escape characters will insert another byte into your packet.  One way around this is to read all the data as chars, process the escape characters, and then use the MEX function fourChar2Float to convert the chars into a 32-bit floating point number.

@@ Line 301: / Line 301: @@
 To make your XBee broadcast packets, set the DL parameters to FFFF and the DH parameter to 0.
-===Proprietary API mode===
+===Proprietary API Mode===
 To use the API mode, set the AP parameter to 1 or 2, depending on whether you will need escape characters (see 3.4 in the manual for more information).
@@ Line 307: / Line 307: @@
 Writing software for the API mode may be more difficult, as you have to assemble a packet and calculate a checksum.  You may wish to use API mode if you need to be able to detect corrupt data or if you need to communicate to many different radios individually.
+====Reading Packets with MATLAB in API Modes=====
+You can read XBee API packets with MATLAB using the <tt>fread()</tt> function if you are using API Mode 1, if your packets are the same length.  When using <tt>fread()</tt>, you can specify how many bytes to read, and which data type the bytes should be interpreted as (integer, float, etc.).  However, when using API Mode 2, <tt>fread()</tt> becomes tricky to use because the escape characters will insert another byte into your packet.  One way around this is to read all the data as chars, process the escape characters, and then use the MEX function fourChar2Float to convert the chars into a 32-bit floating point number.
+Download fourChar2Float here: [[Image:fourChar2Float.zip]]
 ===ZigBee Mode===

@@ Line 191: / Line 191: @@
 '''Specific instructions and descriptions of allowable parameters to send can be found in Section 3 of the XBee Product Manual.'''
 Some commonly used commands:
+<table border=1 cellpadding=2 width=75%>
-*+++ Enter command mode
+<tr>
-*ATCN Exit command mode
+	<th>Parameter</th>
-*ATAC Apply changes
+	<th>Description</th>
-*ATWR Write current parameter values to non-volatile memory (must reset or use ATAC for changes to take effect)
+	<th>Command</th>
-*ATRE Restore defaults
+	<th>Value</th>
-*ATFR Reset
+</tr>
-*ATCH Set channel
+<tr>
-*ATID Set network ID
+	<td rowspan=6 align=center>Basic Commands</td>
-*ATDH Set desination ID (high byte)
+	<td>Enter command mode</td>
-*ATDL Set destination ID (low byte)
+	<td align=center>+++</td>
-*ATMY Set device ID
+	<td rowspan=6 align=center>N/A</td>
-*ATBD Set baud rate
+</tr>
-*ATAP Set transparent/API mode
+<tr>
+	<td>Exit command mode</td>
+	<td align=center>ATCN</td>
+</tr>
+<tr>
+	<td>Apply changes</td>
+	<td align=center>ATAC</td>
+</tr>
+<tr>
+	<td>Write current parameter values to non-volatile memory (must reset or use ATAC for changes to take effect)</td>
+	<td align=center>ATWR</td>
+</tr>
+<tr>
+	<td>Restore defaults</td>
+	<td align=center>ATRE</td>
+</tr>
+<tr>
+	<td>Reset</td>
+	<td align=center>ATFR</td>
+</tr>
+<tr>
+	<td colspan=4 align=center><b>For items below, type command followed by a value to set the parameter or without a value to check the current value.</b></td>
+</tr>
+<tr>
+	<td align=center>Baud Rate</td>
+	<td><p>Sets the baud rate at which the XBee communicates with the serial device it is physically connected to.</p><p>See the XBee manual for information on setting non-standard baud rates</p></td>
+	<td align=center>ATBD</td>
+	<td align=center>0-7 (standard baud rates)<br>
+= 1200 bps<br>
+= 2400 bps<br>
+= 4800 bps<br>
+= 9600 bps<br>
+= 19200 bps<br>
+= 38400 bps<br>
+= 57600 bps<br>
+= 115200 bps</td>
+</tr>
+<tr>
+	<td align=center>Radio Channel</td>
+	<td>The XBee can only communicate with other radios using the same channel.</td>
+	<td align=center>ATCH</td>
+	<td align=center>Uses 802.15.4 protocol channel numbers.<br>
+x0B - 0x1A (XBee)<br>
+x0C - 0x17 (XBee-PRO)</td>
+</tr>
+<tr>
+	<td align=center>Personal Area Network (PAN) ID</td>
+	<td>The radio can transmit to a specific network number, or use 0xFFFF to broadcast messages to all PANs</td>
+	<td align=center>ATID</td>
+	<td align=center>16-bit</td>
+</tr>
+<tr>
+	<td rowspan=2 align=center>Serial Number</td>
+	<td rowspan=2>Every radio has a 64-bit, read-only serial number. It can be identified by other radios using this number.</td>
+	<td align=center>ATSH (high byte)</td>
+	<td align=center>N/A</td>
+</tr>
+<tr>	<td align=center>ATSL (low byte)</td><td align=center>N/A</td></tr>
+<tr>
+	<td align=center>16-bit Device ID</td>
+	<td>You can identify a specific XBee using a 16-bit Device ID instead of the 64-bit serial number. See Destination ID for more information.</td>
+	<td align=center>ATMY</td>
+	<td align=center>16-bit</td>
+</tr>
+<tr>
+	<td rowspan=2 align=center>Destination ID</td>
+	<td rowspan=2><p>Specify the device ID of a specific XBee to transmit to or use 0x000000000000FFFF to broadcast to the entire PAN.</p><p>To use 16-bit addressing, set the high byte to 0 and the low byte to the 16-bit Device ID of the XB you are transmitting to.</p></td>
+	<td align=center>ATDH (high byte)</td>
+	<td align=center>16-bit</td>
+</tr>
+<tr>	<td align=center>ATDL (low byte)</td><td align=center>16-bit</td>
+<tr>
+	<td align=center>API Mode</td>
+	<td>Gives you more control over communications between XBees, including non-standard packet sizes. Refer to the XBee manual for more information on API/Transparent Mode.</td>
+	<td align=center>ATAP</td>
+	<td align=center>0 = API disabled (use Transparent Mode)<br>
+= API enabled<br>
+= API enabled (w/ escaped control characters)</td>
+</tr>
+</table>
 ===Transparent Operation===