Home/Support/Support Forum/S3B will transmit not receive

S3B will transmit not receive

0 votes
Hi there, I have 2 S3b radios, one is a programmable unit 900MHz with freescale processor the other a non-programmable unit. The issue I have is one of communication between the two radios.

When using a sparkfun base I can communicate between the two radios in transparent mode. This is bi directional each radio can communicate (send and receive) I am monitoring this through minicom and can clearly see information coming through.

When I use these Xbee's not on the sparkfun base, e.g a simple breakout board I can get communication with the co-ordinator (programmable) but the end node (not programmable will only Transmit and not receive.Ultimately this will go onto an arduino/moteino and run as an end node. I have tried many things to figure this out but am making no headway. Things I have tried so far:

Eliminating a power problem:
the end node has been connected directly to a 3.3v regulator to provide independent power.
the end node has run directly from the 3v3 pins of a moteino in low power trans mode to keep it within boundss of onboard regulator.

When powered by the sparkfun board it is operating from a usb level power regulator. It works on sparkfun.


Eliminating cables
I have swapped all cables around to different devices, each cable will communicate solidly through minicom, I have connected them as a loop and two different minicom ports will talk to each other, thus I assume the FTDI cables are solid.

Trying different bases

I have tried 3 different breakout boards to see if it was a bad connection on the boards at all, this has made no difference.

Testing the comms on the bases
I've removed the xbee and used the rx and tx from minicom directly though the xbee bases into another comm cable, this is working fine.

Trying to wire directly
I have removed the xbee from my breadboard prototype to see if I can limit the wiring to it and bypass as much as possible, this has meant using the breadboard with simply +3v, GND, and then rx and tx, I use the rx and tx of an ftdi cable and also the ground to give a common point. This has made no difference.

Checking with ATND and XCTU
I can get both radios to do a ATND request and this operates on either radio, they both find the other and seem to be connected. This even works on my breadboards which seems strange if they are not receiving.

In xctu I can send remote at commands and get a response, this is when hooked up using a sparkfun base

+++OK
ATND
FFFE
0013A200
40A18BC7
remote4
FFFE
01
00
C105
101E

+++OK
ATND
FFFE
0013A200
40E542F9
centralx
FFFE
01
00
C105
101E

coordinator
+++OK
ATBD
7
ATID
1
ATSM
0
ATPL
2
ATAP
0

end node

+++OK
ATBD
7
ATID
1
ATSM
0
ATPL
1
ATAP
0


When not on the base I can still get a ATND to work and the radios I'm guessing are linked? The end dode radio will still transmit but still no receive.

I hope someone out there can give me a hand with this as it is quite puzzling.

Thankyou
asked Jan 5, 2016 in DigiMesh Proprietary Mesh Networking by simonpearce New to the Community (0 points)

Please log in or register to answer this question.

1 Answer

0 votes
Have you looked at your 3V to 5V level shifters on your UART lines?
answered Jan 6, 2016 by mvut Veteran of the Digi Community (11,302 points)
...