xbee usb communication too slow or another problem?

Question

Hello,

I have two xbee modules serie 1 (using Xbee Explorer USB) and work well when I send serial data between two computers using terminal in xctu in both directions from the end module to the coordinator and from the coordinator to the end module.

But I have no communication when I use a third-party software(mission planner) for emulate USB communication from my computer to arduino APM (like this tutorial http://ardupilot.org/copter/docs/xbee-radios.html), this software work well if I use usb cable connected directly from my computer to the arduino APM. The remote xbee end module show green led for about two seconds then the led is off. My software (mission planner) show a message "can't communicate". Both test was made with the same configuration:

My communication configuration is baud rate=57600, Data Bits=8, Parity=None, Stop Bits=1, Flow control=none

Can anybody help me?

Fadel Cazor

Answer 1

Did you configure the XBee modules for this data rate? Their default rate is 9600 bps.

Comments

Hi mvut, yes of course, both are configured to work at 57600. And they work well at this configuration if I use xctu.

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Have you changed the COM port in which the software is using to communicate with from the USB port to the COM port Windows Assigned the XBee's to?

Are you using API mode or Transparent mode with the XBee modules?

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Yes I tried with another com port assigned to the USB driver changed in windows control panel, then the communication is OK using XCTU, then when I try to communicate to the APM the problem described above occurs again. I made a lot of test changing the communication parameters, changing the wires, changing the USB adapters, but the problem occurs. The only test I don't made is verify if the voltage operation in the remote xbee module have an issue. This voltage is supplied by the lipo batteries of my drone, do you know if there are communication problems in xbee modules with different voltages?

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You can run different voltages but the voltage needs to be within the radios specifications. That is to say, if you are using an OEM Module, than the voltage at the modules VCC needs to be within the modules limits.  For example, if the modules supported VCC limit is 2.8 - 3.4V, and your battery spikes to 4.0V, then it is not going to work without adding some protection circuit. The reason being is that the 4V from the battery will exceed the radios MAC value of 3.4V causing damage.

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Hi Eric,
thank you very much for your answer I think you are right because I saw a video wich describe a similar problem (https://www.youtube.com/watch?v=celzrrGATmI&list=PL15E34CEC8F286914&index=9). But the solution provided by this video I'm not convinced yet because I don't like a non-standard solution, first I will investigate if a 3DR Power Module can solve the problem.

Thank you very much.

Fadel