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Help with Code for Custom Timer

e14 Contributor

I'm trying to build a custom timer but my code doesn't seem to function properly. There are 5 switches that control 1 LED each. When each is pressed they light the LED for a set period of time and when the time is up, a piezo buzzer goes off until the reset button is pressed. I really new to programming the arduino, but I thought I had a pretty good program until I tried to run it. Any guidance would be greatly appreciated!

 

Code is as follows:

/* 5 buttons each representing 30, 60, 90, 120, 180 seconds, when pressed, will illuminate their corresponding LED
and after the time duration is complete, a piezo buzzer will pulse until the reset button is pressed.
*/

// constants that will not change. Used to set pin designations.
const int led30Pin = 13;
const int button30Pin = 12;
const int led60Pin = 11;
const int button60Pin = 10;
const int led90Pin = 9;
const int button90Pin = 8;
const int led120Pin = 7;
const int button120Pin = 6;
const int led180Pin = 5;
const int button180Pin = 4;
const int resetPin = 3;
const int buzzerPin = 2;

// variables that will change
int button30State = 0;
int button60State = 0;
int button90State = 0;
int button120State = 0;
int button180State = 0;
int resetState = 0;
int timeState = 0;

void setup()
{
  // initialize pins as outputs
  pinMode(led30Pin, OUTPUT);
  pinMode(led60Pin, OUTPUT);
  pinMode(led90Pin, OUTPUT);
  pinMode(led120Pin, OUTPUT);
  pinMode(led180Pin, OUTPUT);
  pinMode(buzzerPin, OUTPUT);

  //initialize pins as inputs
  pinMode(button30Pin, INPUT);
  pinMode(button60Pin, INPUT);
  pinMode(button90Pin, INPUT);
  pinMode(button120Pin, INPUT);
  pinMode(button180Pin, INPUT);
  pinMode(resetPin, INPUT);
 
}

void loop()
{
   // read the state of the pushbutton values:
  resetState = digitalRead(resetPin);
  button30State = digitalRead(button30Pin);
  button60State = digitalRead(button60Pin);
  button90State = digitalRead(button90Pin);
  button120State = digitalRead(button120Pin);
  button180State = digitalRead(button180Pin);

  // check if the pushbutton is pressed.
  // if it is, set all LEDs and buzzer LOW:
  if (resetState == HIGH)
  {    
    // turn LEDs and buzzer off:   
    digitalWrite(led30Pin, LOW); 
    digitalWrite(led60Pin, LOW);
    digitalWrite(led90Pin, LOW);
    digitalWrite(led120Pin, LOW);
    digitalWrite(led180Pin, LOW);
    digitalWrite(buzzerPin, LOW);
  }
  // check if pushbutton is pressed.
  //if it is, set led##Pin HIGH and start timerState decrements.
  //when timeState reaches 0, turn buzzerPin HIGH.
  if (button30State == HIGH)
  {
    //turn led30Pin on
    digitalWrite(led30Pin, HIGH);
    (timeState == 30);
    if(timeState > 0);
    delay (1000);
    (timeState --);
    if(timeState == 0);
    digitalWrite(buzzerPin, HIGH); 
  }
  if(button60State ==HIGH)
  {
    digitalWrite(led60Pin, HIGH);
    (timeState == 60);
    if(timeState > 0);
    delay (1000);
    (timeState --);
    if(timeState == 0);
    digitalWrite(buzzerPin, HIGH);
  }
   if(button90State ==HIGH)
  {
    digitalWrite(led90Pin, HIGH);
    (timeState == 90);
    if(timeState > 0);
    delay (1000);
    (timeState --);
    if(timeState == 0);
    digitalWrite(buzzerPin, HIGH);
  }
  if(button120State ==HIGH)
  {
    digitalWrite(led120Pin, HIGH);
    (timeState == 120);
    if(timeState > 0);
    delay (1000);
    (timeState --);
    if(timeState == 0);
    digitalWrite(buzzerPin, HIGH);
  }
  if(button180State ==HIGH)
  {
    digitalWrite(led180Pin, HIGH);
    (timeState == 180);
    if(timeState > 0);
    delay (1000);
    (timeState --);
    if(timeState == 0);
    digitalWrite(buzzerPin, HIGH);
  }
  //otherwise turn all output pins LOW.
  else {
  digitalWrite(buzzerPin, LOW);
  digitalWrite(led30Pin, LOW);
  digitalWrite(led60Pin, LOW);
  digitalWrite(led90Pin, LOW);
  digitalWrite(led120Pin, LOW);
  digitalWrite(led180Pin, LOW);
  }
}

Parents
  • 0

    Hi Adam,

     

    It would re useful to tell us more than "doesn't seem to function properly."  i.e. actual observed behaviour & how have you wired it up (are you sure buttons are low until pressed?)

     

    At any rate I can see you have a problem with this and similar sections:

        (timeState == 30);

        if(timeState > 0);

        delay (1000);

        (timeState --);


    I'm guessing this is meant to loop round 30 * 1-sec delays?


    What it actually does is:

        (timeState == 30); // check if timestate is equal to 30. doesn't change timeState. "=" vs "=="

        if(timeState > 0); // if timeState greater than 0 do nothing (semicolon at end indicates empty statement)

        delay (1000);      // delay 1 sec unconditionally

        (timeState --);    // decrement timeState. ok but parentheses here and 3 lines above are not needed

    ...so whichever button you press you'll see the correct led light, a 1 sec delay, then the buzzer.



    There are many ways to write this, but the following (untested) is close to your original intent:

    timeState = 30;

    while (timeState > 0) {

        delay (1000);

        timeState --;

    }


    You might also want to consider how you're switching things off.  As Keith points out the  "//otherwise turn all output pins LOW." else block is only attached to the last if and will, I think, fire every time through the loop unless button180 is currently pressed.


      Regards,

      Colin


  • 0 in reply to e14 Contributor

    Thanks for the input.

     

    I've changed the code to  look like this for every time button and led.

     

    if (button30State == HIGH)

      {

    digitalWrite(led30Pin, HIGH);

        timeState = 30;

        while(timeState > 0)

        delay (1000);

        timeState --;

        while(timeState <= 0)

        digitalWrite(led30Pin, LOW);

        digitalWrite(buzzerPin, HIGH);

    }

     

    However, now when I press the button, the corresponding led lights up but it never shuts of nor does the buzzer output go high. If I reset the arduino and wait without pressing any buttons, pin 12 goes high and lights the led60Pin LED for some reason.

     

    I have also completely removed the statement at the end:

      else {

      digitalWrite(buzzerPin, LOW);

      digitalWrite(led30Pin, LOW);

      digitalWrite(led60Pin, LOW);

      digitalWrite(led90Pin, LOW);

      digitalWrite(led120Pin, LOW);

      digitalWrite(led180Pin, LOW);

      }

     

    I have not yet added debounce code as I wanted to get the timing functional. All switches have 10k pulldown resistors installed. LEDs are cathode to ground and anode to output pin through 220 ohm resistors.

Reply
  • 0 in reply to e14 Contributor

    Thanks for the input.

     

    I've changed the code to  look like this for every time button and led.

     

    if (button30State == HIGH)

      {

    digitalWrite(led30Pin, HIGH);

        timeState = 30;

        while(timeState > 0)

        delay (1000);

        timeState --;

        while(timeState <= 0)

        digitalWrite(led30Pin, LOW);

        digitalWrite(buzzerPin, HIGH);

    }

     

    However, now when I press the button, the corresponding led lights up but it never shuts of nor does the buzzer output go high. If I reset the arduino and wait without pressing any buttons, pin 12 goes high and lights the led60Pin LED for some reason.

     

    I have also completely removed the statement at the end:

      else {

      digitalWrite(buzzerPin, LOW);

      digitalWrite(led30Pin, LOW);

      digitalWrite(led60Pin, LOW);

      digitalWrite(led90Pin, LOW);

      digitalWrite(led120Pin, LOW);

      digitalWrite(led180Pin, LOW);

      }

     

    I have not yet added debounce code as I wanted to get the timing functional. All switches have 10k pulldown resistors installed. LEDs are cathode to ground and anode to output pin through 220 ohm resistors.

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