I just managed to get around to looking a little deeper into this and connected an oscilloscope to EHRPWM1A (which I figure is pin P9_14) and confirm that when writing a zero to brightness (using echo 0 > /sys/class/backlight/backlight.11/brightness) that the pin is low. Likewise write a '50' sets a 50% duty cycle and LCD brightens. I haven't set up environment to compile and test using 'c' files yet.
With low on pin P9_14 the LCD is still visible. With debian version I now have running, I have not seen the LCD goto sleep yet - still have to look into this. ~C On May 26, 2014, at 8:03 PM, John Syn <[email protected]> wrote: > > From: Colin Bester <[email protected]> > Reply-To: <[email protected]> > Date: Monday, May 26, 2014 at 4:54 PM > To: <[email protected]> > Subject: Re: [beagleboard] BBB LCD3 Cape and inactivity > >> Was wondering if you have come up with any further solution? I can write '0' >> to backlight brightness but while this dims the display significantly it >> doesn't switch if off. > > Have you checked that EHRPWM1A is low when you dim the display? Here are two > files that will control the backlight. > > /driver/video/backlight/pwm_bl.c > /driver/pwm/pwm-tiehrpwm.c > > Regards > John -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
