Multiple LED arrays fading at different rates but at the same time: Question

Using Arduino LEDs and Multiplexing
1

(deleted)

2

You can’t do it like that. You need to use a state machine style of program, like the blink without delay.
You can not use for loops nor delay as that stops things wiring at the same time.

3

Can you draw how they need to fade? And the library in my signature can probably make it easy for you :wink:

4

(deleted)

5

With my library it's very easy to do. And you get gamma correction as a bonus :smiley:

Think this should do it:

#include <FadeLed.h>
#include <Bounce2.h>

FadeLed ledRows[] = {9, 10, 11}; //FadeLed object for these pins
const byte NrLedRows = sizeof(ledRows) / sizeof(FadeLed); //Number of rows
const unsigned long FadeTime = 2000; //Time (in ms) a fade takes
const byte FadeThreshold = 20; //When to start the fade of the next row? in %

const byte ButtonPin = 5;

Bounce button;

void setup(){
  for(byte i = 0; i < NrLedRows; i++){
    ledRows[i].setTime(FadeTime);
    ledRows[i].beginOn();
  }
  
  button.attach(ButtonPin, INPUT_PULLUP);
}

void loop(){
  FadeLed::update();
  button.update();
  
  //Button was pressed, first row is on and not fading
  if(button.fell() && ledRows[0].get() && ledRows[0].done()){
    //start fading the first row to off
    ledRows[0].off();
  }
  
  for(byte i = 1; i < NrLedRows; i++){
    //if the previous row gets under the threshold, and next row isn't already fading or off,
    //start fading the next
    if((ledRows[i - 1].get() <= FadeThreshold) && ledRows[i].done() && !ledRows[i].get()){
      ledRows[i].off();
    }
  }
  
  //If all leds are off, a button press will trigger a turn on (no fade) of all leds
  if(button.fell() && allOff()){
    for(byte i = 0; i < NrLedRows; i++){
      ledRows[i].beginOn();
    }
  }
}

bool allOff(){
  bool rtn = false;
  for(byte i = 0; i < NrLedRows; i++){
    rtn |= ledRows[i].get();
  }
  return !rtn;
}

Does compile but untested because I don't have the hardware on hand.