XBEE LTH sensor error

Python
1

I have a set of XBEE LTH sensors (these were z-net, I upgraded to z-net to zigbee ala http://www.digi.com/support/kbase/kbaseresultdetl.jsp?id=3025) and I am using a ConnectPort x4 to connect to it. The sensors show up fine in the ConnectPort x4 and I can discover the xbee nodes (using for instance the discover.py example script), but I can’t access any of the data through python, none of the test scripts work.

I am just tying a simple test.py python script:


import sys, os
import zigbee

DESTINATION = "[00:13:a2:00:40:5d:38:05]!"
sample = zigbee.ddo_get_param(DESTINATION, '1S')

I get the following error:


Traceback (most recent call last):
  File "WEB/python/test.py", line 38, in ?
    sample = zigbee.ddo_get_param(DESTINATION, '1S')
Exception: ddo_get_param: error fetching DDO parameter.

What am I doing wrong?

2

Also I tried this test script, from the “LTH_example.py” sample script.

import sys
sys.path.append("WEB/python/DigiXBeeDrivers.zip")
import xbeelt
import zigbee
DESTINATION = "[00:13:a2:00:40:5d:38:05]!"
lt = xbeelt.XBeeLTN(DESTINATION)

I get a similar error:

Traceback (most recent call last):
  File "WEB/python/test.py", line 37, in ?
    lt = xbeelt.XBeeLTN(DESTINATION)
  File "WEB/python/DigiXBeeDrivers.zip/xbeelt.py", line 48, in __init__
ValueError: Adapter is not a XBee Sensor /L/T Adapter

Any help would be appreciated!

3

OK, I have the answer. When I upgraded the XBee LTH sensor firmware from Z-NET to ZB, I used the wrong firmware and the wrong settings.

Just a note, the upgrade instructions at http://www.digi.com/support/kbase/kbaseresultdetl.jsp?id=3025 is incomplete, and didn’t have the XBEE LTH sensor information (the correct firmware and settings are located at http://www.digi.com/wiki/developer/index.php/XBee_Sensors). In particular I didn’t set the “DD” value to 0x3000D.

4

Several things are happening here - as you discovered, the iDigi/Dia code requires the lower DD value to one of 2 values - 0x000D or 0x000E.

But also, if the LT sensor is sleeping, trying to ‘poll’ the temperature may result in DDO failures which look worse than they are.

With the LT/LTH sensor, you really want to use the IR, or SN/SP to set a time base for the device to report in. For example my LT sensors usually just push in a reading every 10 or 30 minutes.