LP8550 Slope Configuration

Background:

Macbook air LP8550 backlight IC uses custom slope to adjust brightness smoothly. If you solder on LP8550 from mouser or random ebay seller, you will have default ladder-style brightness adjustment which does not look nice especially when it goes from 10% to 100% due to ambient light change. Turns out this is a simple parameter which could be flashed directly from Linux.

Python 3 Script:

GitHub

Video Tutorial:

All credits to @Piernov

Don't like video tutorials ? Here is the step-by-step with pictures:

1. Boot from a Ubuntu (Live USB works well) and connect to Internet (for updates):
   • Details on creating an Ubuntu live USB for Mac are here: https://ubuntu.com/tutorials/create-a-usb-stick-on-macos#1-overview
2. Enable Universal Repository:
   • Search and launch « Software & Update » in Ubuntu
     

     Find and launch Software & Updates in Ubuntu
   • Check the "Community-maintained free and open-source software (universe)" box
     

     Check the "Community-maintained free and open-source software (universe)" box
   • Close and « Reload »
     

     Click "Close" then click "Reload"
3. Launch Terminal:
   • Install Python 3 by typing the commande below

     sudo apt install python3-smbus
     

     

     Install Python 3 by typing this command
4. Open Web browser and go to https://gist.github.com/piernov
   

   Find set_lp8550_slope.py on Piernov's github in a web browser
5. Open set_lp8550_slope.py, click on « raw » and save it on your desktop. (Ideally, your home folder)
   

   Click on "Raw"
   

   link=File:Save_in_%22home%22.jpg
6. Back to terminal, type « sudo python3 set_lp8550_slope.py »
   

   Launch the python script

   sudo python3 set_lp8550_slope.py
   

7. You're done...