[Tinyos-help] How to wake up a MICA2 sensor

[Ben Buckner]

>-----Original Message-----
>
>Date: Tue, 31 Oct 2006 19:16:49 -0600
>From: "Leon Zhou" <leonster at gmail.com>
>Subject: [Tinyos-help] How to wake up a MICA2 sensor
>To: tinyos-help at Millennium.Berkeley.EDU
>
>Hi,
>
> We're doing a temperature detection project with MICA2 and TinyOS.
> In order to save power, our idea is to let the sensors sleep or be idle
>until the base station sends a wake-up signal to wake them up.
> We would like to know if it is possible to do this with MICA2 and TinyOS,
>if yes, how to do it?
>
> Thanks
>
>Haijia

The most common way is to use the built in low-duty cycle listening feature
available in the PowerManagement interface. It sleeps the mote x% of the
time, and wakes up periodically to listen for commands. The down side is
that you often have to transmit repeatedly before the mote wakes up. You can
find a lot of information on it by searching the contents of this message
board, though in my experience the documentation/comments I can find don't
always jibe with the code I have in my distribution (1.1.11), so a lot of
experimentation was necessary to make it work. Repeated sleep/wake cycles
also seem to have some tendency to lock up the mote in a non responsive
state, but then I may also be doing something wrong. 

Ben