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[on:]

I have problems in communication between the arduino and my computer, specifically with the serial monitor!

I, for example, press the button to increment a variable, but the vast majority of the time, it does not increment or decrement.

This is an example of part of the program for incrementing and decrementing.
Not taking into account the variables that have no interest for.

Principal:

Code:

int contaa = 0;
int contab = 0;
int contac = 0;
int contad = 0;
int a = 0;
int b = 0;
int c = 0;
int d = 3;
int e = 3;
int n = 0;

//---------------------------------------------------------------------------------------------
//Funcão principal //Funcão principal //Funcão principal //Funcão principal //Funcão principal//
//---------------------------------------------------------------------------------------------
void setup()
{
  Serial.begin(9600);   //Inicia comunicación serial
  pinMode(0,INPUT); //Sensor Toque a incremental
  pinMode(1,INPUT); //Sensor Toque a decremental
  pinMode(2,INPUT); //Sensor Toque b incremental
  pinMode(3,INPUT); //Sensor Toque b decremental
  pinMode(4,INPUT); //Sensor Toque c incremental
  pinMode(5,INPUT); //Sensor Toque c decremental
  pinMode(6,INPUT); //Sensor Toque d incremental
  pinMode(7,INPUT); //Sensor Toque d decremental
  pinMode(8,OUTPUT); //SSD a
  pinMode(9,OUTPUT); //SSD b
  pinMode(10,OUTPUT); //SSD c
  pinMode(11,OUTPUT); //SSD d
  pinMode(12,OUTPUT); //Led a
  pinMode(13,OUTPUT); //Led b
  pinMode(14,OUTPUT); //Led c
  pinMode(15,OUTPUT); //Led d
}

void loop()
{
  contagem();
}

Incrementing and desrementing part:

Code:

//-------------------------------------------------------------------------------------------------------------------------------------//
// Contadores de semáforos // Contadores de semáforos // Contadores de semáforos // Contadores de semáforos // Contadores de semáforos //
//-------------------------------------------------------------------------------------------------------------------------------------//
void contagem()
{         
 
  // Contador A  // Contador A  // Contador A  // Contador A  // Contador A
  //Rua da Central de camionagem
  if ( digitalRead(0) == HIGH )
  {
      // flanco descendente
      if ( digitalRead(0) == LOW )
      {
         contaa++;               //Incrementa o contador
         Serial.print("Contador a = ");
         Serial.println(contaa); //Escrever na consola o valor
         delay (100);           // Retardo
      }
  }
    if ( digitalRead(1) == HIGH )
  {
      //
      if ( digitalRead(1) == LOW )
      {
         contaa--;               
         Serial.print("Contador a = ");
         Serial.println(contaa);
         delay (100);           
      }
  }
 
  // Contador B  // Contador B  // Contador B  // Contador B  // Contador B
  //Rua da ANIL
  if ( digitalRead(2) == HIGH )
  {
      if ( digitalRead(2) == LOW )
      {
         contab++;               
         Serial.print("Contador b = ");
         Serial.println(contab);
         delay (100);       
      }
  }
    if ( digitalRead(3) == HIGH )
  {
      //
      if ( digitalRead(3) == LOW )
      {
         contab--;               
         Serial.print("Contador b = ");
         Serial.println(contab);
         delay (100);           
      }
  }
 
  // Contador C  // Contador C  // Contador C  // Contador C  // Contador C
  // Rua do Continente
  if ( digitalRead(4) == HIGH )
  {
      if ( digitalRead(4) == LOW )
      {
         contac++;           
         Serial.print("Contador c = ");
         Serial.println(contac);
         delay (100);         
      }
  }
    if ( digitalRead(5) == HIGH )
  {
      if ( digitalRead(5) == LOW )
      {
         contac--;               
         Serial.print("Contador c = ");
         Serial.println(contac);
         delay (100);           
      }
  }
 
  // Contador D  // Contador D  // Contador D  // Contador D  // Contador D
  // Rua das escolas
  if ( digitalRead(6) == HIGH )
  {
      if ( digitalRead(6) == LOW )
      {
         contad++;               
         Serial.print("Contador d = ");
         Serial.println(contad);
         delay (100);         
      }
  }
    if ( digitalRead(7) == HIGH )
  {
      if ( digitalRead(7) == LOW )
      {
         contad--;               
         Serial.print("Contador d = ");
         Serial.println(contad);
         delay (100);           
      }
  }
}

I need help urgently, for this problem

[Reply #1 on:]

Have you wired up pull-down resistor for your button input pins?

Lefty

[Reply #2 on:]

Have you wired up pull-down resistor for your button input pins?

Lefty

Yes, I also have use pinMode "INPUT_PULLUP", but this not resolve my problem...

[Reply #3 on:]

Have you wired up pull-down resistor for your button input pins?

Lefty

Yes, I also have use pinMode "INPUT_PULLUP", but this not resolve my problem...

Well you can't have both pull-ups and pull-downs used on the same input pin at the same time. Can you describe in detail the complete wiring of a typical button switch you are using and the pinMode command you use to support the button.

All I see in your posted sketch is:  pinMode(0,INPUT);

Lefty

[Reply #4 on:]

Also your software logic on reading inputs seems to me to be flawed:

if ( digitalRead(7) == HIGH )
  {
      if ( digitalRead(7) == LOW )
      {
         contad--;               
         Serial.print("Contador d = ");
         Serial.println(contad);
         delay (100);           
      }
  }

That logic tells me if the switch is High do nothing, if it's Low do nothing also.

Lefty

[Reply #5 on:]

Have you wired up pull-down resistor for your button input pins?

Lefty

Yes, I also have use pinMode "INPUT_PULLUP", but this not resolve my problem...

Well you can't have both pull-ups and pull-downs used on the same input pin at the same time. Can you describe in detail the complete wiring of a typical button switch you are using and the pinMode command you use to support the button.

All I see in your posted sketch is:  pinMode(0,INPUT);

Lefty

In my last code, i have use "INPUT_PULLUP" instead "INPUT".

In that image, I have "INPUT_PULLUP" :
http://img534.imageshack.us/img534/408/arduino.png

[Reply #6 on:]

Also your software logic on reading inputs seems to me to be flawed:

if ( digitalRead(7) == HIGH )
  {
      if ( digitalRead(7) == LOW )
      {
         contad--;               
         Serial.print("Contador d = ");
         Serial.println(contad);
         delay (100);           
      }
  }

That logic tells me if the switch is High do nothing, if it's Low do nothing also.

Lefty

My goal is to make a counter, but actuate only in the falling edge.

[Reply #7 on:]

Also your software logic on reading inputs seems to me to be flawed:

if ( digitalRead(7) == HIGH )
  {
      if ( digitalRead(7) == LOW )
      {
         contad--;               
         Serial.print("Contador d = ");
         Serial.println(contad);
         delay (100);           
      }
  }

That logic tells me if the switch is High do nothing, if it's Low do nothing also.

Lefty

My goal is to make a counter, but actuate only in the falling edge.

Well that logic won't work, the time difference from the first digital read and second digital read is only a few hundred nano seconds at most so the button cannot have changed, there is nothing forcing the code to wait for the button to go low.

Lefty

[Reply #8 on:]

Also your software logic on reading inputs seems to me to be flawed:

if ( digitalRead(7) == HIGH )
  {
      if ( digitalRead(7) == LOW )
      {
         contad--;               
         Serial.print("Contador d = ");
         Serial.println(contad);
         delay (100);           
      }
  }

That logic tells me if the switch is High do nothing, if it's Low do nothing also.

Lefty

My goal is to make a counter, but actuate only in the falling edge.

Well that logic won't work, the time difference from the first digital read and second digital read is only a few hundred nano seconds at most so the button cannot have changed, there is nothing forcing the code to wait for the button to go low.

Lefty

So, what do you sugest?
Where should I put a delay?

[Reply #9 on:]

So, what do you sugest?
Where should I put a delay?

Delay() is rarely the best method of handling timing situations. You need to keep a flag variable of the last state of the digitalRead() command and then when you read it again you compare it to the flag value, if they are the same then nothing changed, if they are different then there was a state change with the button and you then update the flag variable for the next time you check the input pin as well as perform the task you need to do because of the state change.

Lefty

[Reply #10 on:]

So, what do you sugest?
Where should I put a delay?

Delay() is rarely the best method of handling timing situations. You need to keep a flag variable of the last state of the digitalRead() command and then when you read it again you compare it to the flag value, if they are the same then nothing changed, if they are different then there was a state change with the button and you then update the flag variable for the next time you check the input pin as well as perform the task you need to do because of the state change.

Lefty

Can you put a simple code example, please?

[Reply #11 on:]

So, what do you sugest?
Where should I put a delay?

Delay() is rarely the best method of handling timing situations. You need to keep a flag variable of the last state of the digitalRead() command and then when you read it again you compare it to the flag value, if they are the same then nothing changed, if they are different then there was a state change with the button and you then update the flag variable for the next time you check the input pin as well as perform the task you need to do because of the state change.

Lefty

Can you put a simple code example, please?

The Arduino people already gave you an example called StateChageDetection in the files/example/Digital example sketches, but I'll post it here:

Code:

/*
  State change detection (edge detection)
 
 Often, you don't need to know the state of a digital input all the time,
 but you just need to know when the input changes from one state to another.
 For example, you want to know when a button goes from OFF to ON.  This is called
 state change detection, or edge detection.
 
 This example shows how to detect when a button or button changes from off to on
 and on to off.
 
 The circuit:
 * pushbutton attached to pin 2 from +5V
 * 10K resistor attached to pin 2 from ground
 * LED attached from pin 13 to ground (or use the built-in LED on
   most Arduino boards)
 
 created  27 Sep 2005
 modified 30 Aug 2011
 by Tom Igoe

This example code is in the public domain.
 
 http://arduino.cc/en/Tutorial/ButtonStateChange
 
 */

// this constant won't change:
const int  buttonPin = 2;    // the pin that the pushbutton is attached to
const int ledPin = 13;       // the pin that the LED is attached to

// Variables will change:
int buttonPushCounter = 0;   // counter for the number of button presses
int buttonState = 0;         // current state of the button
int lastButtonState = 0;     // previous state of the button

void setup() {
  // initialize the button pin as a input:
  pinMode(buttonPin, INPUT);
  // initialize the LED as an output:
  pinMode(ledPin, OUTPUT);
  // initialize serial communication:
  Serial.begin(9600);
}


void loop() {
  // read the pushbutton input pin:
  buttonState = digitalRead(buttonPin);

  // compare the buttonState to its previous state
  if (buttonState != lastButtonState) {
    // if the state has changed, increment the counter
    if (buttonState == HIGH) {
      // if the current state is HIGH then the button
      // wend from off to on:
      buttonPushCounter++;
      Serial.println("on");
      Serial.print("number of button pushes:  ");
      Serial.println(buttonPushCounter);
    }
    else {
      // if the current state is LOW then the button
      // wend from on to off:
      Serial.println("off");
    }
  }
  // save the current state as the last state,
  //for next time through the loop
  lastButtonState = buttonState;

 
  // turns on the LED every four button pushes by
  // checking the modulo of the button push counter.
  // the modulo function gives you the remainder of
  // the division of two numbers:
  if (buttonPushCounter % 4 == 0) {
    digitalWrite(ledPin, HIGH);
  } else {
   digitalWrite(ledPin, LOW);
  }
 
}

Good luck with your project.

Lefty

[Reply #12 on:]

So, what do you sugest?
Where should I put a delay?

Delay() is rarely the best method of handling timing situations. You need to keep a flag variable of the last state of the digitalRead() command and then when you read it again you compare it to the flag value, if they are the same then nothing changed, if they are different then there was a state change with the button and you then update the flag variable for the next time you check the input pin as well as perform the task you need to do because of the state change.

Lefty

Can you put a simple code example, please?

The Arduino people already gave you an example called StateChageDetection in the files/example/Digital example sketches, but I'll post it here:

Code:

/*
  State change detection (edge detection)
 
 Often, you don't need to know the state of a digital input all the time,
 but you just need to know when the input changes from one state to another.
 For example, you want to know when a button goes from OFF to ON.  This is called
 state change detection, or edge detection.
 
 This example shows how to detect when a button or button changes from off to on
 and on to off.
 
 The circuit:
 * pushbutton attached to pin 2 from +5V
 * 10K resistor attached to pin 2 from ground
 * LED attached from pin 13 to ground (or use the built-in LED on
   most Arduino boards)
 
 created  27 Sep 2005
 modified 30 Aug 2011
 by Tom Igoe

This example code is in the public domain.
 
 http://arduino.cc/en/Tutorial/ButtonStateChange
 
 */

// this constant won't change:
const int  buttonPin = 2;    // the pin that the pushbutton is attached to
const int ledPin = 13;       // the pin that the LED is attached to

// Variables will change:
int buttonPushCounter = 0;   // counter for the number of button presses
int buttonState = 0;         // current state of the button
int lastButtonState = 0;     // previous state of the button

void setup() {
  // initialize the button pin as a input:
  pinMode(buttonPin, INPUT);
  // initialize the LED as an output:
  pinMode(ledPin, OUTPUT);
  // initialize serial communication:
  Serial.begin(9600);
}


void loop() {
  // read the pushbutton input pin:
  buttonState = digitalRead(buttonPin);

  // compare the buttonState to its previous state
  if (buttonState != lastButtonState) {
    // if the state has changed, increment the counter
    if (buttonState == HIGH) {
      // if the current state is HIGH then the button
      // wend from off to on:
      buttonPushCounter++;
      Serial.println("on");
      Serial.print("number of button pushes:  ");
      Serial.println(buttonPushCounter);
    }
    else {
      // if the current state is LOW then the button
      // wend from on to off:
      Serial.println("off");
    }
  }
  // save the current state as the last state,
  //for next time through the loop
  lastButtonState = buttonState;

 
  // turns on the LED every four button pushes by
  // checking the modulo of the button push counter.
  // the modulo function gives you the remainder of
  // the division of two numbers:
  if (buttonPushCounter % 4 == 0) {
    digitalWrite(ledPin, HIGH);
  } else {
   digitalWrite(ledPin, LOW);
  }
 
}

Good luck with your project.

Lefty

OK, thanks, I'll see if they solve my problem.
Thank you for your preoccupation and help.

[Reply #13 on:]

Code:

  if ( digitalRead(0) == HIGH )
  {
      // flanco descendente
      if ( digitalRead(0) == LOW )
      {

Pin 0 is one half of the Serial pins. You can't use pin 0 or 1 for a switch, too.