Forums

R: Re: PWM

Started by Fabio Filippa February 13, 2008
Well, I've not do such application but if I've understand you like to
change the duty-cycle of the PWM output wave accordling to some sinewave
rule.
If this is your work I can think as a first try to set a timer and scan
a look-up table builded with values that following the sinewave fashion.

Just my 2 cents, don't know in detail your application then I can't do
more precise thinking about it.

Regards
Fabio Filippa


-----Messaggio originale-----
Da: Ravi [mailto:p...@rediffmail.com]
Inviato: marted12 febbraio 2008 18.38
A: l...
Oggetto: Re: RE: RE: [lpc2000] PWM

I could able to generate PWM of constant width,
but then how to modulate the width with sine wave amplitude ?
whether I have to make PWMMR1 = sinewave amplitude in ISR routine?
In that case I may not achieve carrier freq of 45 Khz
Bcoz I have to change MR1 in after each PWM pulse.
Is there any other way to do that

Ravi

On Tue, 12 Feb 2008 Paul Curtis wrote :
>Hi,
>
> > Hi Paul,
> > My question is how to use single edge/double edge controlled feature
> > of PWM modulator to generate PWM?
>
>Gee, how about reading the documentation that NXP supply? I mean, it's
>actually quite understandable even for a non-hardware guy like me who
has
>actually programmed up the PWM.
>
>--
>Paul Curtis, Rowley Associates Ltd http://www.rowley.
co.uk
>CrossWorks for ARM, MSP430, AVR, MAXQ, and now Cortex-M3 processors
>









An Engineer's Guide to the LPC2100 Series