PROJECT QUESTION - Need help with LCD with Arduino

[ichthys522]

Hello!

I am having trouble with a project I am working on with an LCD display with an arduino.

This is my project thus far, and I am trying to get the LCD to update on button press. But, whenever I press the button nothing happens.

Here's my code:

#include <LiquidCrystal.h>

#define pass (void)0

using namespace std;

const int buttonPin = 10;
int buttonState = 0;
int lastButtonState = 0;
int buttonPushCount = 0;
bool bPress = false;

int value = 10;
int numPoints = 0;

String points;
String basePoints;

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
void setup()
{
 lcd.begin(16, 2); 
 basePoints = "0000";
 points = basePoints;
 pinMode(buttonPin, INPUT_PULLUP);

  lcd.setCursor(0,0);          
  lcd.print("  POINTS"); 
  lcd.setCursor(2,1);
  lcd.print(points); 
}

void loop()
{

  
  checkButton();

  if(bPress)
  {
    bPress = false;
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("SCORE!");
    lcd.setCursor(2, 1);
    lcd.print("+100");
    delay(1000);
  }
  else
  {
    pass;
  }

}

void checkButton()
{
  buttonState = digitalRead(buttonPin);

  if(buttonState != lastButtonState)
  {
    if(buttonState == LOW)
    {
      bPress = true;
    }
  }

  buttonState = lastButtonState;
}

I am unsure as to what the problem is.
Thank you for reading and your help!

[markd833]

@ichthys522

buttonState = lastButtonState;

You have this the wrong way round. Try:

lastButtonState = buttonState;

What does this bit of code do:

@ichthys522

  else
  {
    pass;
  }

[UKHeliBob]

The pinMode() of your button pin is set to INPUT_PULLUP which means that you need to arrange the circuit to take the button pin LOW when the button is pressed

Is that the way that your circuit is wired ? What is the resistor connected to the button doing there ?

[bidrohini]

Please check your button's connection.

[ichthys522]

The resistor is to connect the button to ground. Is this wrong?

[ichthys522]

Okay, thank you!
That pass keyword is (void)0 (line 3), but I could have implemented it wrong
It's supposed to just skip right through the else statement, "pass" it

[UKHeliBob]

It is not needed when using INPUT_PULLUP. Just take the pin LOW when the button is pressed and detect the change of state and the current LOW state to determine that the button has become pressed

[ichthys522]

Okay! It is working! Here's my code:

#include <LiquidCrystal.h>5



using namespace std;

const int buttonPin = 10;
int buttonState = 0;
int lastButtonState = 0;
int buttonPushCount = 0;
bool bPress = false;

int value = 10;
int numPoints = 0;

String points;
String basePoints;

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
void setup()
{
 lcd.begin(16, 2); 
 basePoints = "0000";
 points = basePoints;
 pinMode(buttonPin, INPUT_PULLUP);

  lcd.setCursor(0,0);          
  lcd.print("  ULTIMATE"); 
  lcd.setCursor(2,1);
  lcd.print("PINBALL");
  delay(1000);
  lcd.clear();
}

void loop()
{
 
  lcd.setCursor(0, 0);
  lcd.print("POINTS:");
  lcd.setCursor(2, 1);
  lcd.print(points);
  
  checkButton();

  if(bPress)
  {
    bPress = false;
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("SCORE!");
    lcd.setCursor(2, 1);
    lcd.print("+100");
    delay(500);
    lcd.clear();
  }

}

void checkButton()
{
  buttonState = digitalRead(buttonPin);

  if(buttonState == LOW)
  {
    bPress = true;
  }
  if(buttonState != lastButtonState)
  {
    if(buttonState == LOW)
    {
      bPress = true;
    }
  }

  lastButtonState = buttonState;
}

Here's the circuit:

I just need to make the point value update

Thank you all for your help, I really appreciate it!
God bless!

[ichthys522]

Here's the code with point update:

#include <LiquidCrystal.h>5

using namespace std;

const int buttonPin = 10;
int buttonState = 0;
int lastButtonState = 0;
int buttonPushCount = 0;
bool bPress = false;

int value = 10;
int numPoints = 0;

String points;
String basePoints;

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
void setup()
{
 lcd.begin(16, 2); 
 int basePoints = 0000;
 numPoints = basePoints;
 pinMode(buttonPin, INPUT_PULLUP);

  lcd.setCursor(0,0);          
  lcd.print("  ULTIMATE"); 
  lcd.setCursor(2,1);
  lcd.print("PINBALL");
  delay(1000);
  lcd.clear();
}

void loop()
{
 
  lcd.setCursor(0, 0);
  lcd.print("POINTS:");
  lcd.setCursor(2, 1);
  lcd.print(numPoints);
  
  checkButton();

  if(bPress)
  {
    bPress = false;
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("SCORE!");
    lcd.setCursor(2, 1);
    lcd.print("+100");
    numPoints = numPoints + 100;
    delay(500);
    lcd.clear();
  }

}

void checkButton()
{
  buttonState = digitalRead(buttonPin);

  if(buttonState == LOW)
  {
    bPress = true;
  }
  if(buttonState != lastButtonState)
  {
    if(buttonState == LOW)
    {
      bPress = true;
    }
  }

  lastButtonState = buttonState;
}