Hi, I have a WSN project that consists of several Xbee series 2 modules measuring temperature. I am trying to determine the power consumption of end devices but I get a little confused reading the modules documentation. The settings of my end devices are as follows, making an star topology:
SM=4
SP=28 sec.
ST=30 sec.
SN=1
IR=31 sec.
So, this way the module sleeps for 28 seconds, wakes up, sends a temperature sample to the coordinator and then sleeps again (it sends only one sample since IR is higher than ST). These settings are just for measurements analysis, in the final design the module wakes up for only 150 msec. and sleeps for over 4 minutes.
Now, I have measured the current with a multimeter and is around 110[microA], which is OK according to the Xbee datasheet ( ~50[microA] during sleep for SM=4) and the temperature sensor (<60[microA]), but during the 30 seconds that the module is awake the measurement is around 15[mA].
Does this mean that the module is in idle mode during this time???, shouldn’t it be in receive mode (~45[mA] according to the datasheet)??. A second question comes to my mind. According to the datasheet in idle mode the receiver is off, does this mean it can’t receive RF data during this 30 sec.?. Maybe I’m just confused about differences between idle mode and receive mode [:-/] . Help please!