Xbee is working but very slowly @115600 --> data corrupted ? Bricked ?

Hi folks !

yesterday, i was testing my hardware for a flight this weekend.

But when i tried the telemetry, i saw the data on my computer with a lot of lag.

I tried this :

With X-CTU :

Unbrick the Xbee in W7 64 bits --> don't work

Unbrick in W7 32 bits --> Firmware 1061 @ 115600 -->OK

Vid, Baudrate & DD are the same.

My APM is plugged with ESC and ESC + USB

--> Change speed in config of ArduPlane2.24+Remzibi+Status_Leds.rar  to 115600 bts for port 3

--> Can connect my APM to the Mission Planer but data are very slow to refresh.

--> In console mode i saw the data corrupted ( ex : Calibrating Gyro ??,)) ??,azd))°?,.... calibrating.... )

-->  Last week, the telemetry was ok @115600 with the port shared with Remzibi.

Should i flash my Xbee again or did i forget something ?

Thanks a lot

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Replies to This Discussion

Thanks for your answer

This is the 900mhz version.

I tried it last week ans haven't notice any bug.

I changed the firmware to 2.24 with remzibi + Led. and works fine too.

I'll try no with the 56k connection. ( Does it change anything in mid range ? 4 or 5 km )

Same thing happened to me, but it wasn't until I was outside in the park that it started to slow. Same Xbee 900. What would cause this?

56k link is enough to show data fluidly on Mission planner ?

I have it set to 57600, as said in the manual, and I am still having this slowing issue.


I am an RF Engineer and have spent several years working with radio equipment operating int the 900 Mhz. ISM band. ISM stands for industrial, scientific and medical. It is an un-licensed band allowing operation there providing the user complies with the limitations set fourth by the FCC. The primary limitations are that the maximum radiated power is no more than 400 mW (.4 watt) at the transmitter port or no more than one watt out of a gain antenna. Additionally all users must agree not to interfere with each other and co-ordinate frequency use between themselves accordingly. No bickering there, the FCC doesn't want to hear it. The Xbee 900 operates in this band along with thousands of other consumer products like cordless telephones and cheap wireless security cameras that hog up half the band just for one camera.

Additionally this tiny little slice of ISM heaven is sandwiched between two lumbering giants for neighbors. below 900 Mhz. was the analog cell phone band which is now being re assigned for other uses. Above 928 Mhz. is the pager transmitter band. Pager transmitters can spew out several hundred watts. This can be a problem if the transmitter is malfunctioning and splattering harmonic spikes down into the 900 ISM band. This is or was a fairly common problem. 

This poses an interesting set of problems when using a device of this type for an UAV that is flying over a course that could encompass several miles.

 The Xbee is not alone as mentioned above. It worked great in the house at close range, but out in the park not so much. it is probably competing with other signals on the same band. data is coming through but it seems to slow down. Look around the horizon to see if you can identify any obvious radio towers nearby. 

The UAV could be flying its course and you have great line of sight with the craft but something closer to it is walking all over your signal and vice-versa. (consult FCC part 15 ISM band rules).

If someone in your group has access to a spectrum analyzer you could have them bring it to you flying field and visually see all the potential signal competition that exists there.

I hope this helps a little.


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