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XBee Pro 900 XSC and APM

Posted by Shaw Innes on December 19, 2010 at 7:55pm

Hi All,

I have managed to get my APM up and running using two XBee 2.4Ghz modules without any problems, however if I swap these modules over and replace them with the XBee Pro 900Mhz modules I get no data coming over the link.  I have set my baud rate to 9600 on both ends and in the APM just to be safe, since that appears to be the maximum RF baud rate supported.

 

What I have noticed is that if I use the test -> xbee mode of the ArduPilot I get "00" bytes coming through to my serial terminal on the PC.  About one a second.

 

Has anyone else encountered similar problems, did I miss something somewhere in the documentation regarding the way the Pro 900 chips work vs the 2.4Ghz ones?

 

Thanks

  Shaw

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Replies

  • karim Abdou March 4, 2013 at 4:00am

    Ok guys just to be sure :

    first i have the same problem of yours and i am using spurkfun's boards.

    1- https://www.sparkfun.com/products/8687

    2-https://www.sparkfun.com/products/11373

    i have checked the xbees on my arduino UNO and my laptop switching an LED , writing in both terminals all wirelessly and  making a range test , all of these works just perfect .

    so my question here : is this violates your assumption about the spurkfun's explorer boards and their incompatibility with APM board ? , or the comparison is injustice in terms of power method that Uno and mega supplies the xbee... 

    i am sorry for my language , i am not native so if you are not understanding any part plz let me know .....

    Thank you all

  • Duncan Greer December 22, 2010 at 6:49pm

    Hi Shaw,

     

    I've been having a simliar problem when using XBeePro XSCs with an Arduino Mega.  I'm receiving zeros at the serial port.

    One problem could be that I'm using Xbee explorers from Sparkfun which may have a current limit problem on transmit (i.e. the regulator is only 150mA, but the XSC needs 265mA).  Another problem could be the VIO levels (Xbee 3.3V) to ArudinoMega 5V - I think usign the Adafruit adapter would rule this out, but I don't have one.

    Have you had any success?

    Duncan.

  • Ritchie December 20, 2010 at 6:19am

    You have the wrong Xbee modules.

    The Xbee 900 Pro XSC has a maximum data rate of 9.6 kbps

    The Xbee 900 Pro has a maximum data rate of 156 kbps

  • Shaw Innes December 20, 2010 at 5:31am

    Thomas -  I don't have one in fornt of me just now - but I'm willing to bet that's the default, and therefore exactly what I've done wrong.

    I'll let you know how I get on when I try it later..

  • Shaw Innes December 20, 2010 at 4:59am

    Hi Chris,

    I did notice that - I changed a few of the defaults:

    #define GCS_PROTOCOL   GCS_PROTOCOL_LEGACY
    #define GCS_PORT          3
    #define SERIAL3_BAUD      9600

    It works fine if I use the 2.4Ghz modules, but not with the 900Mhz ones...

     

    I'm powering the APM off the USB port and I wonder if there isn't enough current to drive the 900Mhz module vs the 2.4Ghz one?  Is this likely? 

     

     

  • 3D Robotics
    Chris Anderson December 19, 2010 at 8:11pm

    All telemetry is sent at 57k unless you've changed it in the config file.

    It's all spelled out in the manual. Is something there unclear?

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