[Tinyos-help] what is the chance of a timer not getting fired ?

mowrang at ucsd.edu mowrang at ucsd.edu
Fri Sep 16 11:17:37 PDT 2005

Thanks Joe!

I have a question about timers:

I have a module that get called every 10sec using a timer. Each time the
timer get fired I increment a counter by one.

Every 600sec(+some margine to let 10sec timer get fired 60 times) I
send the value of the counter to TOSBase.

I run the program for a few hours and plot the histogram of the counter
values and it is less than 60, 40% of the time. It can get as small as
12!(attached please find the histogram)

I have seen some old postings that mentioned that they didn't collect
enough samples while calling the timer with a specific sampling rate. But
they mentioned HOW inaccurate their samplings were.
Can you shed some light to this problem ?

1)I am running this module on top of a MAC that puts nodes to sleep
2)I am using Timer interface (not TimerMilli)
3)I set timers one shot and start them again when the process is completed.

Also I like to know how exactly the timers work when the MSP430 is sleep.
(I didn't find any posting on this)

You said here
that MSP430 goes to sleep automatically when peripherals with high speed
clock are not active. How high this clock should be for MSP430 not to
sleep ?

thanks a LOT LOT!

> 2.1V for the radio; the Blue LED cuts out at 2.7V which was probably
> the problem you saw.  I've run the radio down to 1.15V reliably.
> -Joe
> On 9/15/05, mowrang at ucsd.edu <mowrang at ucsd.edu> wrote:
>> Hi
>> I was running Telos mote to wake-up periodically using Industrial
>> Panasonic Alkaline Batteries.
>> When the battery voltage was 2.3v the LED that was toggeling each time
>> that I turned on the radio, stopped toggling (I was running the code for
>> 4
>> days so I am sure that there is nothing wrong with the code)
>> Is the minimum of 1.8 mentioned at Telos data sheet
>> (http://www.moteiv.com/products/docs/telos-reva-datasheet-r.pdf) only
>> for
>> the processor ?
>> I have read the message at
>> https://mail.millennium.berkeley.edu/pipermail/tinyos-help/2005-January/007193.html
>> However still I didn't get my answer for sure.
>> Maryam
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