One sender, others receive. Packetizing problems?

Hi all,

Short overview of the setup:
I have one sender and four receivers. I need to send 1 byte, four times per second.
If a packet is dropped, that’s not a big issue, getting new data is more important. So, packetization should not happen.

I thought about using Xbee modules (S2B series).
The sender will always be on wall power, the others battery powered. I configured the sender as coordinator, the others as routers.

My programming skills are not good enough yet to use API mode.

I’ve configured the coordinator with
DH/DL = 0/0xFFFF
RO = 0

This still has the coordinator sending the data out in bursts every few seconds. I’ve tried programming the microcontroller sending the data to
-enter command mode,
-set the adress of the first receiver,
-exit command mode,
-send byte,

and so on for every byte (so four times a second), but can’t get the setup reliable enough, sometimes the xbee doesn’t go into command mode. I don’t think this is the best solution anyway.

I’ve read through the whole datasheet searching for a better solution, and I’m wondering about SE and SD settings.
Should I configure these? If so, how?

Or is this setup doomed to fail and should I look further?



Dieter, that would be the wrong product for this. Try using the XBee 802.15.4 modules or the 868LP. Both are better suited for what you want to do.

I see, thanks.
I’ll certainly take that into consideration next time, which I should have done before picking this product. At the time, these modules seemed perfect.

As I have already purchased them, is there any way I can get this to work with these modules for now?

As mvut said, even I felt that 802.15.4 is a better solution for your project.

If you still wish to make most out of these modules then set baud rate high to values like BD=115200 and decrease broadcast radius to lowest i.e. BH=0x01.

You cannot keep Rx modules on battery. At this rate, I don’t think batteries will even last from a week. And SE and SD parameter are totally irrelevant with your issue.

Thank you for your advice.

I will implement the devices as good as possible and next time check here first for advice on which modules to use.
Seems like I seriously misjudged the purpose of this product.

The modules are powered by 11500mAh battery packs, and even then, only need to operate for a couple of hours between cycles.