problem with multiple xbee modems II

The problem persisted even if I did not checked in my software the response.
However, once I turn on the "second" modem things work out just fine. The "second" modem was the one to whom once messages started being sent interfered with the normal working of the modem at the robot. Why??
I am not sure, but at least the problem is narrowed to the Xbee modems, maybe a configuration that can be set via XCTU...
More on that later...

problem with multiple xbee modems

I am currently going through some major problems. So far tests were just fine when using only one coordinator an one destination modem (both router and endnode). However when I tried to use a setup with 3 modems (coordinator + router + endnode) I am experiencing serious lags in communication, for example the gamepad commands take very long to arrive the destination.
In this tests, there is a program that sends messages at a rate of 2Hz, destinated to a modem that is not turned on. (this may be one of the problems, I remember now that once I powered that other modem, things were fine, or am I mistaken?).
Anyway, I am trying to figure out now where is the bottleneck in this setup. I may be in the way I am handling messages at the computer, it may be hardware limitations (xbee buffer, serial channel speed, wireless comm speed...).

robot base validation videos

these three videos show initial tests and final results in constructing a robot based on a rc car chassis. the first video shows the command of the steering angle using an arduino that is receiving commands from the keyboard of a laptop:


the second video shows the robot being remotely commanded by a gamepad via a xbee modem:


the third video is a test of the robot actually moving on the laboratory floor, commanded by a gamepad:

New arduino fio

This is a picture of the new arduino board to be used in this project. It is very small, has an integrated Xbee socket and a LiPo charger. The new power source (LiPo 1000mAh) is also in that picture.

Here is a comparison between the duemilanove and the fio boards:

Xbee api + robot

Today I manage to repeat the setup that could command the robot base using the gamepad, via xbee. However the xbee modem is working in API mode. The message payload has three bytes, the first one is used to provide the signal of direction and speed, the second is the direction value and the third is the speed.
The results are much better compared to the older implementation using xbee AT mode. This may be due to the data structure that is now being used.
Now I will post pictures and videos of the completed robot at this point, as it will be unmounted to test the new arduino fio board, with the new 3.7v power supply.
I still want to test the robot behaviour when the coordinator is also sending messages to other modems.