Aboat LED driver and FLASH life

Jixiang Jiang

root@tl:/sys/devices/platform/leds-gpio.1/leds/user_led1# ls
brightness device max_brightness power subsystem trigger uevent
root@tl:/sys/devices/platform/leds-gpio.1/leds/user_led1# cat brightness
255

In the LED driver, the content in file "brightness" indicates the LED is light or not.

if the LED flicker quickly for a long time, will it reduce the FLASH life?

Or the file "brightness" is just exist in RAM?

over 8 years ago

0 Titusrathinaraj Stalin over 8 years ago

TI__Guru** 116100 points

Hi,
Its about brightness of the LED.
If you want to power OFF the LED then give "0" then it will not glow.
If you give 120,128 etc., then the LED illumination will be less.

Ex:

echo 0 > /sys/devices/platform/leds-gpio.1/leds/user_led1/brightness
echo 120 > /sys/devices/platform/leds-gpio.1/leds/user_led1/brightness
echo 128 > /sys/devices/platform/leds-gpio.1/leds/user_led1/brightness

0 Arvind Singh over 8 years ago

Mastermind 6115 points

Hi Jixiang jiang,

if the LED flicker quickly for a long time, will it reduce the FLASH life?

It will not reduce Flash life, because program execution happens in RAM not in flash memory.

0 Jixiang Jiang over 8 years ago in reply to Arvind Singh

Prodigy 40 points

Thanks, I'm still not sure.
I can see it in the file system, does that mean this kinds of files are not exist in FLASH at all, but in RAM?

0 Titusrathinaraj Stalin over 8 years ago in reply to Jixiang Jiang

TI__Guru** 116100 points

Yes,
If you have filesystem on USB or SD card or network (NFS booting) then you won't see this file at all since it is pseudo filesystem (virtual).

You will get that file when kernel is booted.

Ex:
SYSFS,PROCFS etc.,

en.wikipedia.org/.../Sysfs

0 Arvind Singh over 8 years ago in reply to Jixiang Jiang

Mastermind 6115 points

Hi Jixiang,

I can see it in the file system, does that mean this kinds of files are not exist in FLASH at all, but in RAM?

Hope Titus Answer would have cleared your doubt now. Let us know if you still facing any issues.

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Aboat LED driver and FLASH life