AVR-Chat

Hi Guys,

The Tiny13 cannot use an external crystal or ceramic resonator. The
only way of getting an accurate clock is an external oscillator into
the CLKI pin. This would require building a oscillator around a
crystal. It really looks like the better long run option would be to
either use the internal oscillator and only examine parts of the
incoming IR signal as previously suggested or upgrade to a chip that
has a built in oscillator that a crystal or ceramic resonator can be
fitted to.

Cheers
Hein B
Auckland, New Zealand.

--- In AVR-Chat@yahoogroups.com, "Richard Cooke" <rcooke@...> wrote:
>
> Hi Folks,
> 
> I'm just starting this project where I'd like to use an ATtiny13 (for
> cost and size reasons) to monitor an IR receiver chip.  When the
> processor sees three pulses it will energize a relay.
> 
> I'll just have it sit in a loop waiting for the first pulse.  The 1st
> pulse is 2000us then no pulses for 27800us, another pulse of 400us, no
> pulse for 1500us then one more pulse of 400us.
> 
> I just have to detect the pulses (no data is being transmitted) so
> does it look like I can use the internal osc?  This app will normally
> be used at a temp of 10C to 30C.  I don't want to re-invent the wheel
> so if anybody has any ideas where to start I'd appreciate it.
> 
> I've come up with two ways to attack this.  First would be to setup
> the timer and actually time the pulses and second would be to just
> sample the input and the midpoint of the pulses and gaps to verify
> that they occurred.  Since there will only be these 3 pulses with
> these timings this should simplfy matters.
> 
> What do you think?
> 
> Thanks,
> 
> Richard Cooke
> Lake Forest, CA
>