Am 29.09.11 09:39, schrieb Reinoud Zandijk: > Hi Marc, > > On Wed, Sep 28, 2011 at 10:05:31PM +0200, Marc Balmer wrote: >> Marc.... > > sorry :-D > >>> On Sun, Sep 25, 2011 at 11:42:11AM +0200, Marc Balmer wrote: >>> I'd like to be able to set the PWM indepentently for each pin! say >>> specifying >>> 70/256 on and otherwise off. >> >> That is what gpiopwm(4) is for. >> >>> gpiopwm(4) can be grouped on pins that needs synchronisation. Say gpiopwm0 @ >>> gpio0 has pins 3, 5, 7 with each their pwm's but synchronised on 'on' or >>> 'off' >>> and gpiopwm1 @ gpio0 has pin 2 and 8. As they are synchronised all the pins >>> attached can be programmed at one go preventing arbitrary races. >> >> How can you sync if the pins have different duty cycles? > > Well they could all start at the same time, say a pin0 @ 70/256 and a pin1 @ > 45/256 can start both at t=0 and pin1 dropping at t=44 and pin0 dropping at > t=69 and both keeping low until t=256. > > The base duty cycle will then be the same for say a gpiopwm0, only different > portions of the > time on/off for the pins connected to gpiopwn0. > > Is this more clear?
Yes, I understand now what you mean, but that is not PWM anymore. A duty cycle repeats itself all the time. What you describe is more of a repeated single-shot. I will first do what I have now, PWM. Such a single shot thingie could be shoehorned into it later, now that we have flags. > > With regards, > Reinoud >
