From: Colin Bester <[email protected]> Reply-To: <[email protected]> Date: Thursday, May 29, 2014 at 6:45 AM To: <[email protected]> Subject: Re: [beagleboard] BBB LCD3 Cape and inactivity
> 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 ¹50¹ sets a 50% duty cycle and LCD brightens. I haven¹t set up > environment to compile and test using OEc¹ files yet. > > With low on pin P9_14 the LCD is still visible. In that case this is a hardware issue. P9_14 is connected to the enable pin of the LED backplane driver so the leds should turn off. Regards, John > > 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. -- 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.
