Hi,
I’m trying to create a simple sensor node using one XBee with the “XB24-ZB Zigbee end device AT” feature set version 28A0 on hardware version 1947 and a coordinator XBee in API mode version 21A0 and seem to have fallen at the first hurdle.
The end device XBee has the following settings:
D1 2
SM 4
ST 3E8
SP AF0
SN 4
IR DC
V+ C00
The sample i’m interested in is taken on AD1.
As I understand things the settings above should make the Xbee sleep for 2800x10msx4 (112seconds, 1 minute 52seconds), and assuming there is no RF data waiting for it, wake for 1000ms and send IO samples every 220ms (ie 4 samples every period). In practice what i am seeing is the sleep LED connected to pin 13 coming on as expected every 112 seconds however samples only get transmitted to the coordinator every ~4x112seconds. Regardless of ST/SN settings samples are only transmitted every ~4SNSP even though the sleep pin is asserted every SN*SP. The lines below show the output from the coordinator via processing API library:
21:34.47 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 599 supply voltage: 576 temp: 20.3?C
21:34.47 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 601 supply voltage: 592 temp: 20.5?C
21:34.47 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 599 supply voltage: 576 temp: 20.3?C
21:34.48 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 602 supply voltage: 592 temp: 20.6?C
21:42.10 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 602 supply voltage: 572 temp: 20.6?C
21:42.10 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 604 supply voltage: 592 temp: 20.9?C
21:42.10 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 602 supply voltage: 572 temp: 20.6?C
21:42.10 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 604 supply voltage: 592 temp: 20.9?C
21:49.32 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 593 supply voltage: 572 temp: 19.6?C
21:49.33 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 596 supply voltage: 592 temp: 19.9?C
21:49.33 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 594 supply voltage: 576 temp: 19.7?C
21:49.33 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 596 supply voltage: 592 temp: 19.9?C
21:56.55 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 587 supply voltage: 572 temp: 18.9?C
21:56.55 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 590 supply voltage: 592 temp: 19.2?C
21:56.56 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 588 supply voltage: 572 temp: 19.0?C
21:56.56 Sender address: 00:13:a2:00:40:71:a6:a1 analog value: 590 supply voltage: 592 temp: 19.2?C
I’ve tried this with a couple of XBee modules and found the same behavoir so i’m clearly either missing or misunderstanding something. Any ideas?
Cheers,
Matt