I've been quite busy lately with making something that should once become a wireless, Arduino based sensor 'platform'.
Unfortunately i don't have the tools (yet) to measure power consumption of what I've constructed until now, but that can be solved
Here's the latest update on this project:Now that i managed to put an XBee ZB module to sleep, all i had left to do was being able to put the RBBB to sleep for a certain amount of time (and have it wake up again!). It would be very nice if i could use 2 types of triggers for waking up the controller: on a predefined interval and by some external source (for example an attached motion detector that detects motion). Both are actually equally important, so i tossed a coin with the outcome that i started with trying to accomplish to wake up the RBBB on a predefined interval.
I found an article that pretty much did what i wanted. The maximum time that the Watchdog Timer can power down the micro-controller is 8 seconds, after which it will wake up again and carry on with it’s job. I modified some things so that the power down routine is called multiple times, which results in a power down mode in multiples of 8 seconds. Currently the wake up interval is set at 32 (4*8) seconds and it has run flawlessly for >24 hours now. I still have to dig deeper into the Watchdog code see if my ‘modifications’ can be made more efficient, but for now this will be OK.
Now i wonder what the power consumption of this combination of RBBB and Zigbee module is… should i let it run on a battery and wait till it stops? How long will that be…. no; i think it’s better to find a way to estimate battery life by actually measuring the power consumption. That will probably mean i will need extra hardware and tools.
You can read more posts about this project on my web log of which most were already posted somewhere else on this forum.