https://learn.adafruit.com/adafruit-pit ... stallation
Everything works except the backlight control. when I try and run
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sudo sh -c "echo 252 > /sys/class/gpio/export"
ls -l /sys/class/gpio
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pi@raspberrypi:~$ ls -l /sys/class/gpio
total 0
-rwxrwx--- 1 root gpio 4096 Apr 7 00:28 export
lrwxrwxrwx 1 root gpio 0 Jan 1 1970 gpiochip0 -> ../../devices/virtual/gpio/gpiochip0
-rwxrwx--- 1 root gpio 4096 Jan 1 1970 unexport
pi@raspberrypi:~$
Working on a battery operated pi project so need the ability to shut the back light off when not in use.
Second question is about the LCD itself. Is there a data sheet available for it? If not does anyone have the electrical details on the LEDs and their arrangement used for the back light? Looking at the logic they are the only devices powered by 5V. I am in the process of laying out a switching regulator card to replace the three linear regs on the Pi. (again for power savings) As part of that process I want to switch to a switching reg to power the back light but need the LED info to select the best one.
Thanks,