Looping within a case statement

Using Arduino Programming Questions
1

So ive been playing around with making a toggle switch control 3 modes of an LED. I want it to have an on state, a fading in and out state, and an off state. Ive jumbled some code and kinda rigged a sketch together, but I keep having the same problem of the sketch getting stuck in the loop for the fade. Is there a way to have a loop within a case statement, or what would be the best way to tackle this. Heres is the code Im currently using. (I though that if I had the loop take place outside the case statement it would continue to detect the button states.

Any help would be awesome as I am new to this whole Arduino thing.

Thanks!

const int ledPinOne = 0; // LED1 ANODE
const int modePin = 4; // Active HIGH, held low by 4.7K
 
int mode = 0; // Selector State (Initial state = ALL OFF)
int val = 0; // Pin 0 HIGH/LOW Status
int butState = 0; // Last Button State
int modeState = 0; // Last Mode State
int fadeCheck = 0; //check for fade mode
 
//===============================================================
// SETUP
//===============================================================
void setup () {
 pinMode(ledPinOne, OUTPUT);
 pinMode(modePin, INPUT);
 }
 
//===============================================================
// Main Loop
//===============================================================
void loop() {
 
 val = digitalRead(modePin);
 
 // If we see a change in button state, increment mode value
 
 if (val != butState && val == HIGH){
 mode++;
 }
 
 butState = val; // Keep track of most recent button state
 
 // No need to keep setting pins *every* loop
 if (modeState != mode){
 
 // If no keys have been pressed yet don't execute
 // the switch code below
 // if (mode != 0) {
 
 switch ( mode ) {
 //case 1 is actually handled below as default
 
case 2:
 digitalWrite(ledPinOne, HIGH);
 fadeCheck = 0;
 break;
 case 3:
 fadeCheck = 1;
 fade();
 break;
 default:
 mode = 1;
 fadeCheck = 0;
 digitalWrite(ledPinOne, LOW);
 break;
 } // end switch

   // end of "if mode = 0" check
 } // end of ModeState check
 modeState = mode; // Keep track of mode recent mode value
 delay(10); // slow the loop just a bit for debounce
  
}
  
  
  void fade()
  { 
    while(fadeCheck ==1)
    {
    for (int fadeValue = 0 ; fadeValue <= 255; fadeValue += 5) 
    {
    // sets the value (range from 0 to 255):
    analogWrite(ledPinOne, fadeValue);
    // wait for 30 milliseconds to see the dimming effect
    delay(30);
    }

  // fade out from max to min in increments of 5 points:
  for (int fadeValue = 255 ; fadeValue >= 0; fadeValue -= 5) 
    {
    // sets the value (range from 0 to 255):
    analogWrite(ledPinOne, fadeValue);
    // wait for 30 milliseconds to see the dimming effect
    delay(30);
    }
 	}
  }
2 
while(fadeCheck ==1)

Since nothing inside the while loop ever changes fadeCheck, you're going to be stuck here forever. IF fadeCheck is 1 to start the loop and never changes inside the while loop then fadeCheck will never ever be anything but 1.

You have to adjust your thinking. Don't think of a function that fades the led up and down. Don't think of a case with a loop in it. You already have the loop function running over and over. Think instead of a case that gets called over and over. Think of a function that takes one step of the fade and then returns and when loop calls it again takes the next step of the fade and returns and when loop calls it again takes the next step of the fade and returns.

3

And if you want to make the whole fading business easy: