A20 LCd showtdown

Started by ebelouet, July 16, 2014, 07:12:05 PM

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ebelouet

Hi,

I would like how switch OFF power of TFT LCD ?

Linux or Python commandes ?

Sincerely
E belouet

MBR

#1
You can turn the LCD off either by disabling via GPIO or setting PWM to zero. I'm not sure what GPIO pin does control the LCD on A20 (try looking on the schematics or in /etc/rc.local), but the PWM should be the same file /sys/class/pwm-sunxi/pwm0/duty_percent. All you need is write (text) zero here, for example try (as root and preferably via SSH) echo 0 > /sys/class/pwm-sunxi/pwm0/duty_percent .


otyugh

Erh.
Nothing such /sys/class/pwm-sunxi/pwm0/duty_percent ; and rc.local just change the following :

Quotechmod 777 /dev/disp  /dev/cedar_dev /dev/ump  /dev/mali
echo 1008000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq

echo 408000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq

./opt/led_blink.sh&

dave-at-axon

Quote from: MBR on July 22, 2014, 05:24:46 PM
I'm not sure what GPIO pin does control the LCD on A20

There is a separate POWER control via a GPIO pin and a PWM pin for the backlight.

ebelouet

Hi,

Thank but do you have python example because I don't find this adress in python library ?

Sincerely
Eric