[Tinyos-help] [tinyos2.0] event timer.fired() getting lost on telosb using BlinkToRadio apps.

[Cory Sharp]

Boomerang has no significant changes from the 2.x timer stack.  We are
actively looking into this issue, now. - Cory

On 7/23/06, Philip Levis <pal at cs.stanford.edu> wrote:
> On Jul 23, 2006, at 11:37 AM, Jonathan Hui wrote:
>
> > After a little testing, it looks like the radio stack is still alive.
> > I modified BlinkToRadio to maintain two timers (1ms and 1s period),
> > both of which attemps to send a message on each fire event. After a
> > few moments, the 1ms timer will fail to fire, but the 1s timer will
> > continue firing and sending messages. Even more interesting is that
> > the 1ms timer starts firing at the same period as the 1s timer.
> >
> > It's probably the case that the radio stack is somehow affecting the
> > operation of the msp430 timer stack and causing it to fail in
> > repeatedly firing the 1ms timer. Haven't dug too much into the timer
> > code to understand why this is.
> >
> > I've attached the modified app I used to test.
> >
> > Cory, do you have an ideas?
>
> Yeah, I should have given more background. I think it's definitely
> the case that it's the MSP430 timer stack, which runs into some
> issues when timers are at too fast a rate (e.g., 1ms). E.g., in the
> 2.0 tutorials, there's a part where you try using very long tasks of
> different length to show the run-to-completion semantics. On atm128
> platforms, a task that's too long causes you to lose timer events but
> things continue as expected; on msp430 ones, the timer stack can act
> erratically.
>
> Joe, Cory, does Boomerang 2.0.2 use the 2.x timer stack unchanged, or
> have you incorporated fixes?
>
> Phil
>