[sdiy] Timing : How close is close enough?

[Tom Arnold]

On Wed, Feb 04, 2009 at 12:32:01AM +0000, Tom Wiltshire wrote:
> I'd have thought you can do *much* better than "10000 times a  
> second". This is an accuracy of 100uS. The cheap PIC 16Fs that I've  
> used have timers that will run up to 5MHz IIRC (1/4 the max clock),  
> which is an accuracy of 200 *nS*. This is an improvement of 3 orders  
> of magnitude.
> 
> In short, a $2 chip will get you *so* close that you won't even  
> bother asking if it's close enough.

The 10000 number came from rough numbers of a 16mhz Atmel also reading the
front panel and updating LED readouts and the like.  I bet you are correct
that I can get far more then that, but as I'm thinking about playing with
this as my first Arduino project instead of coding in ASM like I normally
do so for discussions sake I assumed a worst-case scenerio.

-- 
 --------------------------------------------------------------------
 - Tom Arnold           -  "...is it a virus, a drug, or a religion?"  
 - Sysabend Caretaker   -    Juanita Shrugs. "What's the difference?"
 ------------------------       -- Neal Stephenson,  Snow Crash