[Tinyos-help] Time counting

[Philip Levis]

On Jan 3, 2007, at 6:43 PM, Michael Newman wrote:

> I was definitely led astray by the introductory material and the  
> tutorials. They all talk about milliseconds and provide examples  
> such as Blink where 1000 milliseconds is used as a timer argument  
> and is described as a 1 second interval.
>
> From the blink code and readme:
>
> Blink is a basic application that starts a 1Hz timer and toggles  
> the red
> LED every time it fires. It is a very simple program that is little
> more than a demonstration of TinyOS programming.
>
>   command result_t StdControl.start() {
>     // Start a repeating timer that fires every 1000ms
>     return call Timer.start(TIMER_REPEAT, 1000);
>   }

Well, to be fair, the tutorials and apps like Blink are intended to  
be the simple introduction to TinyOS. A discussion of binary kHz and  
decimal kHz might be a bit beyond what the app is supposed to  
demonstrate. The TinyOS 2.x tutorial doesn't mention milliseconds  
explicitly, and does reference TEP 102. One of the issues we always  
run into with TinyOS documentation is the huge spectrum of user  
backgrounds, ranging from "how do I set an environment variable" to  
"platform X needs to configure GPIO pin Y to state Z on  
initialization because of condition foo." That's why there are  
multiple forms: the general conclusion is that no single document  
will be able to satisfy everyone, so there are layers.

Phil