XBee mesh coordinator not hearing from all radios

XBee & XBee Gateway XBee Programamble (S2C & 900 HP)
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1

Hi folks,

I have been trying to get a simple XBee Sensor Mesh up and working. Both of my sensor radios are able to speak to the Coordinator, but I can only receive packets from 1 at a time. Both of my endpoint are configured as routers. I will give details below of how things are configured, but will describe symptoms first.

I start up my coordinator radio and then router A. I get TX packets from A at the coordinator. I then start up router B which is connected to identical hardware. I only get packets from A, no matter how long I wait.

I then shut down radio A and I start receiving packets from B. I restart A, but only receive packets from B. I eventually shut down B and I start receiving packets from A. I can go back and forth like this for a long time. So each individual radio can contact the coordinator just fine, they just can’t do it at the same time. Everything is being tested on my workbench.

Though it shouldn’t matter, the router radios are both attached to an Arduino Pro which is reading the SHT15 temperature/humidity sensor and a light sensor. The coordinator is attached to a Sparkfun USB Explorer and is speaking to a library which knows how to obtain the packets.

All radios are S2 XBees.

The Coordinator is set for XB24-ZB. The firmware is ZigBee Coordinator API , firmware version 21A0.
The Pan ID is set for 2000. DH/DL is 0/FFFF. No Node Identifier is set. AP is set to 2. Everything else is left at the default values.

Router A is set for XB24-ZB. The firmware is ZigBee Router API, firmware version 23A0.
Pan ID, 2000. DH/DL: 0/FFFF… No Node Identifier is set. AP is set to 2. MY got FB10. Everything else is left at the default values.

Router B is set for XB24-ZB. The firmware is ZigBee Router API, firmware version 23A0.
Pan ID, 2000. DH/DL: 0/FFFF… No Node Identifier is set. AP is set to 2. MY got A107. Everything else is left at the default values.

Thoughts?
-Keith

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Right now, both your routers are transmitting in broadcast mode which is uselessly taking lot of bandwidth space.

Set DL=0 on both Routers (alias address of coordinator) and observe if its improves situation.

3

Keith,

First, set the DL and DH of both routers to 0 or the SL and SH of the Coordinator. This will reduce the amount of broadcasts occurring. This may in it’s self solve the issue. If it does not, decrease the amount of data packets both are sending. That should solve it.

4

OK, thanks folks for the help, I appreciate it very much.

I did finally figure out the solution. I don’t think it was packet lengths as the packets were less than 32 bytes. Also, the TX packets were directly addressed to the coordinator, that means, I believe, that the destination address in the firmware was ignored. But I did change DL to 0 anyway.

I checked on the sensor radios and they were getting the acknowledge packet back. I finally checked with another library for the coordinator and saw packets from both radios. I also saw packets from both using XCTU-NG. At this point I figured it was the library I was using, and sure enough, I found a bug, which I fixed.

OK, now I can get on to doing something with the data.