I'm working on a project that transmits measured temperature and humidity wirelessly through a pair of Xbee's.
Xbee S2 C is connected to PC as a coordinator.
Xbee S2 E is connected to ATMEGA328P as an end device. ATMEGA328P samples the temperature and humidity and send the data through Xbee E.
Xbee E, ATMEGA328P, and the sensor will be running on a battery, so I want to minimize the quiescent power consumption.
After Xbee E transmits the data one time, it goes into pin sleep mode (SM=1) by asserting sleep request pin from ATMEGA328P.
The problem starts here.
If I wake Xbee E in about less than 5 seconds, the network is still alive and the data can be sent right after the wake-up (seems like 13.2ms wake-up time is right as per the user manual). However, if I wake Xbee E after sleep of longer than 5 seconds, the network association seems to be lost and Xbee E tries the association from the beginning, which takes 10-15 seconds. This is too long for battery-based operation.
I tried to change related controls (SC, SD, ...), but couldn't see any change.
I would appreciate any advice.