Macbook Air 2012 Keyboard Breathing Effect

Hardware
,
#1

So ive managed to get my macbook air 2012 backlit keyboard to have a breathing effect. This is done by writing values from 0-255 to the applesmc driver which controls the keyboard backlight

Here is the code that does it. It needs to be ran as root to access the driver

#!/bin/bash

SLEEP=0.005 #Delay for sleep. Controls how fast the breathing is
LED=/sys/devices/platform/applesmc.768/leds/smc::kbd_backlight/brightness #Points to where brightness is controlled
counter=$(cat $LED) #sets up the counter variable so that is used for keeping track of brightness

while true
do
        while [ $counter -ge 0 ] #Increment Counter
        do
                echo $counter > $LED
                (( counter++ ))
                sleep $SLEEP
                if [ $counter = 255 ]
                then
                        break
                fi
        done

        while [ $counter -le 255 ] #Decrement counter
        do
                echo $counter > $LED
                (( counter-- ))
                sleep $SLEEP
                if [ $counter = 0 ]
                then
                        break
                fi
        done

done

There is a slight problem with this implementation problem right now. It uses almost 10% cpu power to run which may not be the best thing. I reserve this problem as being a bash problem. I might try to rewrite this in python later and see if that helps out

3 Likes
The Lounge 0001 [From the Beginning]
#2

Nice great work. In the video that effect looks so natural that you’d think it was a design feature build into the laptop. the breathing on my keyboard looks almost exactly like that with similar timing.

1 Like
#3

Yep. Timing worked itself out because the lower end brightness values have much less fine grain control so the breathing effect speeds up on its own :smiley:

1 Like
#4

lel neat that it worked out like that, its a feature not a bug

1 Like
#5

yep. The only bad thing about this is that it uses almost 10% cpu to run. Im gonna reserve this down to being bash

#6

yea knowing bash possibly. would it not be an option to port it over to another shell like ash or zsh? Not sure if there would be much improvement though.

#7

no idea. im guessing most of the wasted cpu is down to massive amount of open() and close() calls im making to that file

#8

ah if thats the case then probably not. is a shame though because it looks really good :frowning:

1 Like
#9

@Dje4321 just a quick question, What is a Macboor Air?

#10

Apple “thin and light” models of macbooks

#11

Screenshot%20from%202018-02-08_21%3A50%3A00

What is this though XD

2 Likes
#12

if that was attempt at pun 1/10 nice try tho

:stuck_out_tongue:
edit
waiit
i see now lol
english, strikes again

1 Like
#13

me not good at spelling

3 Likes
#14

Should talk to @Main_Main about that :stuck_out_tongue:

2 Likes
#15

I know the struggles, I empathize with your plight

3 Likes
#16

so how do i run it some one please run trough it for me

2 Likes
#17

@Michael has this problem been solved yet?

There is a slight problem with this implementation problem right now. It uses almost 10% cpu power to run which may not be the best thing.

If not, then I’d argue that using 10% of the CPU just for a keyboard backlight effect is kind of waste. Neat gimmick, but that’s a lot of CPU power.

1 Like
#18

Hey and welcome, I’ll try and go through the basic process of running this script.

  1. Firstly copy the script and save it to file as something like breath.sh
  2. Open a Terminal session and assign the execute permissions to the file with:
chmod +x breath.sh
  1. Now you should be able to run the script with:
sudo ./breath.sh

Also as a side note as it wasn’t mentioned in the original post, I believe this script was designed to run on Linux and I’m not sure whether it will also work in macOS or if it has the same access to the smcdriver needed for this script to run. @Dje4321 who wrote this script should know more on this as I don’t have access to a device with macOS to test it.

I don’t believe so? Dje mention it might’ve been an issue with bash so it may have had an update in the last two years that makes this run better but I really can’t say.

1 Like
#19

My bad. I thought it was you who wrote the bash script. Time for new glasses indeed when I can’t tell your avatars apart at a glance.

1 Like
#20

i am really fucking stupid so where do i copy it
the code
also i swiched to pc so im used to it