How to Sequentially Activate Pins while Reading from a Sensor ?

Hi, I am starting with Arduino and I am in need of some help. I am trying to sequentially activate 5 pins. I need each pin to be active for 20 seconds in a PWM manner. During their active period I want an arduino sensor to constantly read out the signals emmited by each pin effector. So far I have no problems with the PWM or sensing module code. However I am not able to find how to correctly sequentially activate the pins. I used millis(), etc, but so far I was able to only activate / read the signals from the first pin effector. The sketch doesn´t proceed to the 2nd --- pins. I really very much appreciate your help ....

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0 dtsartsanis over 10 years ago

If you post your code someone will help you
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0 balearicdynamics over 10 years ago

Hello Alejandro,

please post your code or at least your idea of code architecture. Anyway the better solution I see is to use a timer interrupt or a bare interrupt but in this case you have a pin locked by the interrupt trigger. Take in account that using this tecnique you can't use the delay() or millis() count anymore. In many cases I have used millis() that is efficient as it will work in a very similar way as software interrupt. Without your code I think it is really impossible to give you a more detailed advice.
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0 aureta over 10 years ago in reply to dtsartsanis

Hi Dimitros, here´s the code so far...

const int greenPin = 11;
const int redPin = 10;
const int irPin = 5;
const int bluePin = 6;
const int yellowPin = 9;
const int outputLDR = 12;

const int ldrSensor = A0;

int brightness = 0;
int increment = 1;

int readingoutputLDR = 0;

void setup()
{
pinMode(greenPin, OUTPUT);
pinMode(redPin, OUTPUT);
pinMode(irPin, OUTPUT);
pinMode(bluePin, OUTPUT);
pinMode(yellowPin, OUTPUT);
Serial.begin(9600);

setup_parallax();
}

void loop()
{

digitalWrite(outputLDR, HIGH);
readingoutputLDR = analogRead(ldrSensor);

while (millis()<5000)
                {
                   if(brightness > 255)
                   {
                    increment = -1; // count down after reaching 255
                   }
                   else if(brightness < 1)
                   {
                   increment = 1; // count up after dropping back down to 0
                   }
                   brightness = brightness + increment;
                   analogWrite(greenPin, brightness); digitalWrite(redPin, LOW); digitalWrite(irPin, LOW);
                   digitalWrite(bluePin, LOW); digitalWrite(yellowPin, LOW);
                   Serial.print("Reading Green"); parallax_output();
                 }

delay(1);

while (millis()<5000)
                {
                   if(brightness > 255)
                   {
                    increment = -1; // count down after reaching 255
                   }
                   else if(brightness < 1)
                   {
                   increment = 1; // count up after dropping back down to 0
                   }
                   brightness = brightness + increment;
                   delay(1);

                   digitalWrite(greenPin, LOW); analogWrite(redPin, brightness); digitalWrite(irPin, LOW);
                   digitalWrite(bluePin, LOW); digitalWrite(yellowPin, LOW);
                  Serial.print("Reading Red"); parallax_output();
                }

while (millis()<5000)
                {
                   if(brightness > 255)
                   {
                    increment = -1; // count down after reaching 255
                   }
                   else if(brightness < 1)
                   {
                   increment = 1; // count up after dropping back down to 0
                   }
                   brightness = brightness + increment;
                   delay(1);

                   digitalWrite(greenPin, LOW); digitalWrite(redPin, LOW); analogWrite(irPin, brightness);
                   digitalWrite(bluePin, LOW); digitalWrite(yellowPin, LOW);
                    Serial.print("Reading IR"); parallax_output();
                }

while (millis()<5000)
                {
                   if(brightness > 255)
                   {
                    increment = -1; // count down after reaching 255
                   }
                   else if(brightness < 1)
                   {
                   increment = 1; // count up after dropping back down to 0
                   }
                   brightness = brightness + increment;
                   delay(1);

                   digitalWrite(greenPin, LOW); digitalWrite(redPin, LOW); digitalWrite(irPin, LOW);
                   analogWrite(bluePin, brightness); digitalWrite(yellowPin, LOW);
                   Serial.print("Reading Blue"); parallax_output();
                }

while (millis()<5000)
                {
                   if(brightness > 255)
                   {
                    increment = -1; // count down after reaching 255
                   }
                   else if(brightness < 1)
                   {
                   increment = 1; // count up after dropping back down to 0
                   }
                   brightness = brightness + increment;
                   delay(1);

                   digitalWrite(greenPin, LOW); digitalWrite(redPin, LOW); digitalWrite(irPin, LOW); digitalWrite(bluePin, LOW);                   analogWrite(yellowPin, brightness);
                  Serial.print("Reading Yellow"); parallax_output();
                }

}

void parallax_output()
{

                   Serial.print("DATA,DATE,TIME,");

                   Serial.println(readingoutputLDR);

}

void setup_parallax()
{
    Serial.println("CLEARDATA");
    Serial.println("LABEL,Date,Time,Green Response, Red Response, IR Response, Blue Response, Yellow Response");
}
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0 balearicdynamics over 10 years ago in reply to aureta

Hello,

your mistake is in the use of millis() With this function you get the number of milliseconds occured from the last power-on of the microcontroller. So you should not put while(millis()<5000) because it occurs only one time, before the first 5 seconds the program run! Try something like this

[...]

int myTime = 0; // The time delay counter

int eventCounter = 0; // The event counter you need

void setup() {

// your stuff

myTime = millis(); // init the time counter

eventCounter = 1; // start first event

}

void loop() {

// Check if 5 seconds has passed

if( (millis() - myTime) > 5000) ) {

     // Process the current event

     switch(eventCounter) {

          case 1: // event 1

               // your stuff for event 1

              eventCounter++; // next event ...

              myTime = millis(); // reset the time counter

          break;

          case 2: // event 2

               // your stuff for event 2

              eventCounter++; // next event ...

              myTime = millis(); // reset the time counter

          break;

          case 3: // event 3

               // your stuff for event 3

              eventCounter++; // next event ...

              myTime = millis(); // reset the time counter

          break;



          // And so on... for all the events you need to manage in sequence every 5 seconds

          // Then, the last event, as you should restart to the first event

          case 5: // event 5, the last

               // your stuff for event 5

               eventCounter = 1; // next time restart to the first event

               myTime = millis(); // reset the time counter

          break;

     } // end event processing

} // every 5 seconds

}
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0 aureta over 10 years ago in reply to balearicdynamics

Hi Enrico, thanks a lot for your help. I modified the code but seems there are compilation problems that I can´t see. I am att below the modified code, I will appreciate very much if you can take a look at it, Alex.

const int greenPin = 11;
const int redPin = 10;
const int irPin = 5;
const int bluePin = 6;
const int yellowPin = 9;
const int outputLDR = 12;

const int ldrSensor = A0;

int brightness = 0;
int increment = 1;

int readingoutputLDR = 0;

int myTime = 0; // The time delay counter
int eventCounter = 0; // The event counter you need

void setup()
{
pinMode(greenPin, OUTPUT);
pinMode(redPin, OUTPUT);
pinMode(irPin, OUTPUT);
pinMode(bluePin, OUTPUT);
pinMode(yellowPin, OUTPUT);
Serial.begin(9600);
myTime = millis(); // init the time counter
eventCounter = 1; // start first event
setup_parallax();
}

void loop()

{

// Check if 5 seconds has passed
if ((millis()- myTime) > 5000))
{
     // Process the current event
                   switch(eventCounter)
                   {
                          case 1: // event 1
                                 // your stuff for event 1
                                 if(brightness > 255)
                                  {
                                   increment = -1; // count down after reaching 255
                                  }
                                  else if(brightness < 1)
                                  {
                                   increment = 1; // count up after dropping back down to 0
                                  }
                                   brightness = brightness + increment;
                                  analogWrite(greenPin, brightness); digitalWrite(redPin, LOW); digitalWrite(irPin, LOW);
                                  digitalWrite(bluePin, LOW); digitalWrite(yellowPin, LOW);
                                  Serial.print("Reading Green"); parallax_output();

               eventCounter++; // next event ...
               myTime = millis(); // reset the time counter
               break;



                          case 2: // event 2
                                  // your stuff for event 2
                                 if(brightness > 255)
                                    {
                                     increment = -1; // count down after reaching 255
                                    }
                                     else if(brightness < 1)
                                    {
                                     increment = 1; // count up after dropping back down to 0
                                    }
                                    brightness = brightness + increment;
                                     digitalWrite(greenPin, LOW); analogWrite(redPin, brightness); digitalWrite(irPin, LOW);
                                     digitalWrite(bluePin, LOW); digitalWrite(yellowPin, LOW);
                                     Serial.print("Reading Red"); parallax_output();
                eventCounter++; // next event ...
                myTime = millis(); // reset the time counter
                break;


          case 3: // event 3
               // your stuff for event 3
               if(brightness > 255)
                   {
                    increment = -1; // count down after reaching 255
                   }
                   else if (brightness < 1)
                   {
                   increment = 1; // count up after dropping back down to 0
                   }
                   brightness = brightness + increment;


                   digitalWrite(greenPin, LOW); digitalWrite(redPin, LOW); analogWrite(irPin, brightness);
                   digitalWrite(bluePin, LOW); digitalWrite(yellowPin, LOW);
                    Serial.print("Reading IR"); parallax_output();
              eventCounter++; // next event ...
              myTime = millis(); // reset the time counter
          break;


          case 4: // event 4
               // your stuff for event 4
               if(brightness > 255)
                   {
                    increment = -1; // count down after reaching 255
                   }
                   else if(brightness < 1)
                   {
                   increment = 1; // count up after dropping back down to 0
                   }
                   brightness = brightness + increment;


                   digitalWrite(greenPin, LOW); digitalWrite(redPin, LOW); digitalWrite(irPin, LOW);
                   analogWrite(bluePin, brightness); digitalWrite(yellowPin, LOW);
                   Serial.print("Reading Blue"); parallax_output();
              eventCounter++; // next event ...
              myTime = millis(); // reset the time counter
          break;




          // And so on... for all the events you need to manage in sequence every 5 seconds
          // Then, the last event, as you should restart to the first event

          case 5: // event 5, the last
               // your stuff for event 5
                if(brightness > 255)
                   {
                    increment = -1; // count down after reaching 255
                   }
                   else if(brightness < 1)
                   {
                   increment = 1; // count up after dropping back down to 0
                   }
                   brightness = brightness + increment;


                   digitalWrite(greenPin, LOW); digitalWrite(redPin, LOW); digitalWrite(irPin, LOW); digitalWrite(bluePin, LOW);
                   analogWrite(yellowPin, brightness); Serial.print("Reading Yellow"); parallax_output();


               eventCounter = 1; // next time restart to the first event
               myTime = millis(); // reset the time counter
          break;
     } // end event processing
} // every 5 seconds
}

void parallax_output()
{

                   Serial.print("DATA,DATE,TIME,");

                   Serial.println(readingoutputLDR);

}

void setup_parallax()
{
    Serial.println("CLEARDATA");
    Serial.println("LABEL,Date,Time,Green Response, Red Response, IR Response, Blue Response, Yellow Response");
}
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0 balearicdynamics over 10 years ago in reply to aureta

Line 37 - removed an extra ')'
Correct as follows:
if ( (millis()- myTime) > 5000)

That's all. Then compile.

Regards.
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0 aureta over 10 years ago in reply to balearicdynamics

Right, LEDs are glowing. There´s a problem though, my intention is that each pin or led should be continuosly active for at least five seconds in a PWM manner. During this time I want to read the effect on a LDR, I need LDR response curves to LED lights. In this modified sketch, the pins are sequentially activated for 5 sec but the PWM increase is seen only after successive cycles (next activation step for each LED). Seems that it goes all through the code before changing LED intensity levels. ..... If you can help me with this (I really need it) I will be extremely happy. Alex
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0 aureta over 10 years ago in reply to aureta

I´ve got it working, i kept the original while millis() statements but included windows of time for during which each pin should be activated. ....
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