Slider and led help

Good morning
I open another post because I am not convinced of the answers I have been given regarding my problem
perhaps due to the misunderstanding of English (google translated) and therefore the problem is not well solved
I’ll recap the code I’m doing:
I have 3 leds named f, s, b and a slider that drives a fourth ledsilngularly everything works regularly!
BUT when I move the slider (0-255) the first 3 LEDs light up when they meet the character attributed to each LED (f, s, b)
is there anyone who can give me an android mode processing code?
thank you so much

Here is the previous post for those joining this topic:

For continuity…