How to get serial going on S2B module

XBee & XBee Gateway
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1

Using XCTU, I am sending test TX Request Frames (0x10)from Coordinator to Router every 5000ms.

WORKS: If I have the Router connected to the PC via USB I can see that the frames are received at the router in XCTU. Connecting the logic analyzer to pin 2 of the Router I can see the frame leaving the serial interface of the Router.

DOES NOT WORK: If I have the Router connected to only 3.3v power; connecting the logic analyzer to pin 2 of the Router, I CAN NOT SEE ANYTHING on TX.

Other observations:

  1. I do see pulses on the RSSI pin but nothing on pin 2 or pin 3.
  2. The Associate pin shows association.
  3. From XCTU on the Coordinator I can discover the Router and change configuration values over the air.
  4. From XCTU on the Coordinator I can query the temp and supply voltage on the Router. Supply voltage is right at 3.3v.

Is the Router in some strange mode on power up that disables the serial interface?

Configuration:

XBee S2B connected to PC as API Coordinator (USB)

XBee S2B connected to Logic Analyzer as API Router
…PIN 1 3.3v
…PIN 2 Data Out of XBee
…PIN 3 Data In to XBee
…PIN 10 Ground/Common
…PIN RTS is HIGH

…BD = 4(19200)
…All other serial settings at default

Test Environment:

Logic Analyzer on XBee Router pins 2, 3, 6

Sending test TX Request frames from Coordinator to Router every 5000ms.

2

try checking RTS and making sure you are not holding it low.

3

This is what I see with the logic analyzer.

With the coordinator not sending frames:
Pin02 Tx is HIGH
Pin03 Rx is HIGH
Pin16 RSSI is LOW
Pin16 RTS is HIGH

With the coordinator sending frames:
Pin02 Tx is HIGH
Pin03 Rx is HIGH
Pin16 RSSI is Pulsing
Pin16 RTS is HIGH

4

This is what I see with the logic analyzer.

With the coordinator not sending frames:
Pin02 Tx is HIGH
Pin03 Rx is HIGH
Pin16 RSSI is LOW
Pin16 RTS is HIGH

With the coordinator sending frames:
Pin02 Tx is HIGH
Pin03 Rx is HIGH
Pin16 RSSI is Pulsing
Pin16 RTS is HIGH

5

/Router Profile/

XBP24-ZB_23A7_S2B.xml

  773686D686AA75EF
  100
  3
  0
  FF
  0
  1
  1
  13A200
  409C92D6
  0x20Router C
  1E
  0
  FF
  30000
  3C
  0
  3
  0
  1
  0
  0
  
  6
  0
  0
  0
  0
  2
  1
  0
  1
  0
  20
  1388
  0
  1
  0
  0
  0
  0
  1
  1
  0
  0
  1FFF
  FF
  FF
  1
  0
  0
  0
6

/Coordinator Profile/

XB24-ZB_21A7.xml

  773686D686AA75EF
  100
  3
  0
  FF
  0
  FFFF
  0x20Coordinator
  1E
  0
  FF
  30000
  3C
  0
  3
  0
  1
  0
  0
  
  
  6
  0
  0
  1
  0
  2
  1
  20
  1
  1
  0
  0
  0
  0
  1
  1
  0
  0
  1FFF
  FF
  FF
  1
  0
  0
  0
7

Test Frame:

7E //Start
00 12 //Length
10 //Frame Type
01 //Frame ID
00 00 00 00 00 00 FF FF //64-bit destination addr (0xffff => broadcast)
FF FE //16-bit addr
00 //Broadcast radius (0x00 unlimited)
00 //Options
41 41 41 41 //Data" “AAAA”
EF //Checksum

Test Frame:
7E 00 12 10 01 00 00 00 00 00 00 FF FF FF FE 00 00 41 41 41 41 EF

8

SOLVED!

The ROUTER is programmable and sits waiting for an input to the boot loader menu:

B-Bypass Mode
F-Update App
T-Timeout
V-BL Version
A-App

All I had to do was send a ‘B’ to the Serial interface of the XBee and the XBee starts working as advertised.

9

Makes me wounder if your router is associated or not. If you query the AI, CH and ID values, what do they say? What do they say on the Coordinator?

10

Thanks for looking at the problem mvut. I found and posted the solution on the March 9th. The XBee was getting stuck on the boot loader menu.