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Title: A13-SOM-512 does not dim 4.3 LCD backlight
Post by: tkunz on February 19, 2016, 08:13:09 AM

Hi,
I have both the A13-OLinuxino and the A13-SOM-512. Each can drive the A13-LCD43TS that I have, however only the Olinuxino can dim the backlight. I have the exact same kernel and modules on the A13-SOM-512 and A13-Olinuxino. All attempts to dim the screen fail on the A13-SOM-512, but it works just fine with the A13-Olinuxino.

Any ideas?
Thanks!
Tom

Title: Re: A13-SOM-512 does not dim 4.3 LCD backlight
Post by: ulink on February 19, 2016, 01:36:10 PM

Works here like a charm here. Maybe you should check your FEX file:

[lcd0_para]
lcd_pwm_not_used = 0
lcd_pwm_used = 1
lcd_pwm = port:PB02<2><0><default><default>
lcd_pwm_ch = 0
lcd_pwm_freq = 5000
lcd_pwm_pol = 0

[pwm0_para]
pwm_used = 1
pwm_period = 5000
pwm_duty_percent = 50

Don't forget to create the .bin from the .fex and then reboot.
Now you shold be able to dim between 1 and 100 percent (0=100 also, think should try it as root):

50 percent: echo 50 > /sys/class/pwm-sunxi/pwm0/duty_percent

Title: Re: A13-SOM-512 does not dim 4.3 LCD backlight
Post by: tkunz on March 11, 2016, 05:43:52 PM

I should add, I made the changes you recommended and it ended up working just fine.

Olimex Support Forum

OLinuXino Android / Linux boards and System On Modules => A13 => Topic started by: tkunz on February 19, 2016, 08:13:09 AM