a real PWM (= ontime 0%-100%) with just set and forget counters?

StefanL38

Hi counterexperts,

is it possible to configure the counter or maybe if using two counters to create an endless ongoing
(= not a pulsetrain) PWM-signal?

Setup 1/2 counter(s) f.e. 20% ontime and then "forget" it as the counter(s) are producing the PWM-signal
automatically without any additional repeated changing of counterregisters?

keep the answers coming
best regards

Stefan

MagIO2

Hmmm .... shouldn't that work with 2 pins and an external part?!

You setup 2 counters each one is driving one pin. You then connect the pins with an XOR. (The output of the XOR is then the PWM signal.)
Both pins in sync will give you 0%, both pins generating the exact opposite signal give you 100%. Each value in between will give you a value in between and is equivalent to the phase-shift.

Right???

JonnyMac

If you want variable duty cycle with varying frequency as duty cycle changes, yes; if you want to maintain a fixed frequency with variable duty cycle (e.g., for motor control), then you cannot do it without a code loop (Spin or PASM).

kuroneko

StefanL38 wrote: »

is it possible to configure the counter or maybe if using two counters to create an endless ongoing (= not a pulsetrain) PWM-signal?

Yes. Check [post=940154]this post[/post].

Tracy Allen

That became,
http://obex.parallax.com/objects/668/

StefanL38

Hi Jon, kuroneko and tracy,

thank you very much for pointing to the different solutions.

best regards

Stefan