Help with millis

Projects Programming
1

I added the brightness code to fade an led in this sketch but is executing both functions at the same time.
I would like to be able to hold the same button for more than 3,5 sec to change the brightness only.

    btnStateUp = digitalRead(UPPIN);

    startTime = millis();

    if((btnStateUp == HIGH) && (lastBtnStateUP == LOW))  // Switch is pressed and was not
      btnPressCountUpDn++;                                 // Count this press
    lastBtnStateUP = btnStateUp;                     // Use btnPressCount

    if((btnStateUp == HIGH) && (millis() + startTime) > 3500) 
      brightness ++;
    delay(10);
    if (brightness > 255)
      brightness = 255;
2

It would help if you posted all of your code and not just a fragment so we can see it in context.

but is executing both functions at the same time.

Both which functions?

(millis() + startTime)
Will always be > 3500 after the first 1.75 seconds of running this code.

3 
#define REDPIN 3
#define GREENPIN 5
#define BLUEPIN 6

#define UPPIN 4
#define DNPIN 2

int btnPressCountUpDn = 0;

int btnStateUp = 0; 
int lastBtnStateUp = 0;

int btnStateDn = 0;
int lastBtnStateDn = 0;


unsigned long startTime = 0;
int brightness = 30;    // how bright the LED is, stores the brigthness value


void setup() 
{ 
  pinMode(UPPIN, INPUT);     
  pinMode(DNPIN, INPUT);

  Serial.begin(9600);
}

void loop()
{ 
  startTime = millis();

  btnStateUp = digitalRead(UPPIN); // read the PIN and store it

  if((btnStateUp == HIGH) && (lastBtnStateUp == LOW))   // true if operands are true
    btnPressCountUpDn++;       // Count this press, 
  lastBtnStateUp = btnStateUp;                     // Use btnPressCount
  
// This is the part I aded, but is fading at he same time is changing cases
  if((btnStateUp == HIGH) && (millis() + startTime) > 3500) 
    brightness ++;
  delay(10);
  if (brightness > 255)
    brightness = 255;

  btnStateDn = digitalRead(DNPIN); // read the PIN and store it
  if((btnStateDn == HIGH) && (lastBtnStateDn == LOW)) // check the current state of the button
    btnPressCountUpDn--;                                  // Count this press, if is true
  lastBtnStateDn = btnStateDn;                      // reset btnStateDn


    //this part mantains the counts equal to 0 
  // so it doesn't make the btnPressCount unsigned
  if(btnPressCountUpDn < 0)  // <-- Add me
    btnPressCountUpDn = 0; // <-- And me

  Serial.println(btnStateUp);         
  Serial.print(", ");
  Serial.println(btnPressCountUpDn);         


  btnPressCountUpDn = btnPressCountUpDn % 7;               // Keep count in the range 0 to 6



  switch(btnPressCountUpDn)
  {    
  case 0:
    analogWrite(REDPIN,brightness);   // starts with all on
    analogWrite(GREENPIN, brightness);   
    analogWrite(BLUEPIN, brightness);
    break; 

  case 1:
    analogWrite(REDPIN, brightness);   // on
    analogWrite(GREENPIN, 0);    // off
    analogWrite(BLUEPIN, 0);
    break;

  case 2:
    analogWrite(REDPIN, 0);  
    analogWrite(GREENPIN, brightness);   
    analogWrite(BLUEPIN, 0 );     
    break; 

  case 3:
    analogWrite(REDPIN, 0);   
    analogWrite(GREENPIN, 0);   
    analogWrite(BLUEPIN, brightness);
    break; 

  case 4:
    analogWrite(REDPIN, brightness);   
    analogWrite(GREENPIN, brightness);     
    analogWrite(BLUEPIN, 0);
    break;

  case 5:
    analogWrite(REDPIN, 0);  
    analogWrite(GREENPIN, brightness);   
    analogWrite(BLUEPIN,brightness);
    break; 

  case 6:
    analogWrite(REDPIN, brightness);  
    analogWrite(GREENPIN, 0);   
    analogWrite(BLUEPIN, brightness);
    break; 

  }
}
4

Thanks but you still haven't corrected the fault I pointed out:-

(millis() + startTime)
Will always be > 3500 after the first 1.75 seconds of running this code.

I am sure this is not what you want.
You might want
(millis() - startTime)
in the if statement?
Even so this will then never exceed 3700 because at the start of each loop you have
startTime = millis();
so it is constantly reseting

5

Even so this will then never exceed 3700 because at the start of each loop you have
startTime = millis();
so it is constantly reseting

so I need it at the end?

6

so I need it at the end?

No you need it only when you first detect the button is being held down.

7

Ok, is working but the cases are not changing and the LEDs are flashing

void loop()
{ 
  btnStateUp = digitalRead(UPPIN); // read the PIN and store it
 
  if((btnStateUp == HIGH) && (lastBtnStateUp == LOW))   // true if operands are true
    startTime = millis();
    btnPressCountUpDn++;       // Count this press, 
  lastBtnStateUp = btnStateUp;                     // Use btnPressCount

  // This is the part I aded, but is fading at he same time is changing cases
  if((btnStateUp == HIGH) && (millis() - startTime) > 3500) 
    brightness ++;
  delay(10);

  if (brightness > 255)
    brightness = 255;
8

So what do you see in the console from the serial print?

9

btnStateUP and btnPressCountUPDN going from 0 to 7,
4
0
, 5
0
, 6
0
, 7
0
, 1
0
, 2
0
, 3
0
, 4
0
and when I press the button it changes to this,
5
1
, 6
1
, 7
1
, 1
1
, 2
1
, 3
1
, 4

10

Well its doing exactly what you wrote,
What did you expect to see?
Put a print statement in each case to check that it is getting into the right part of the switch statement.