Digital Fade

Projects Programming
1

hi, I found digital fade code:

int ledPin = 24;      // LED CONNECTED TO DIGITAL PIN 13
int value = LOW;    // PREVIOUS VALUE OF THE LED
long cnt = 0;         // WILL STORE LAST TIME LED WAS UPDATED
long low = 0;         // INTERVAL AT WHICH TO BLINK (MILLISECONDS)
long high = 1000; // INTERVAL AT WHICH TO BLINK (MILLISECONDS)
int op = 3;
long a = 0;
 
void setup()
{
  pinMode(ledPin, OUTPUT);      // SETS THE DIGITAL PIN AS OUTPUT
}
 
void loop()
{
  a += op; 
  blinkl( a+30, 200-a);
  if( a > 200 || a < 0 ) op *= -1;
}
 
void blinkl(long low, long high ) 
{  
  int c = 5;
  while ( c > 0 ) { 
   blink( low, high ); 
   c-=1; 
 }
}
 
void blink( long low, long high ) 
{
  long period = 4000;
  long pt = period * high / (low + high );
  int value = LOW;
  digitalWrite(ledPin, value);
   
  while( period > 0 ) {    
    if (period < pt && value == LOW ) {  
      value = HIGH;
      digitalWrite(ledPin, value);      
    }   
    period -= 1;
  }  
}

I want to know how to bright to max and stop or fade to minimum and stop
Can anyone help me to figured out how to do this?

2 
void bright_to_max(int PWM_pin) {
     for (int i=0; i<256; i++) {
        analogWrite(PWM_pin, i);
        delay(10);  // Higher delay = slower fade
    }
}

void fade_to_minimum(int PWM_pin) {
     for (int i=255; i>=0; i--) {
        analogWrite(PWM_pin, i);
        delay(10);  // Higher delay = slower fade
    }
}