How do I get it to return only once?

Projects Programming
1

So I have a pushbutton and I want it to return "TRUE" whenever I push it with debounce. Here is my code, yet whenever I push it, it returns TRUE twice, everytime I press it and release it. I only want it to return true when its pressed and not released. Any help would be great.

#include <Servo.h>

Servo myservo;

int init_pos = 90; //Positions for servo to sort nuts
int pos1 = 30;
int pos2 = 70;
int pos3 = 110;
int pos4 = 150;

int buttonPin = 8; //Variables for push button
int buttonState = LOW;
int lastButtonState = LOW;
unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 50;



void setup() {
  // put your setup code here, to run once:

Serial.begin(9600);
pinMode(buttonPin, INPUT); 

myservo.attach(9);  // attaches the servo on pin 9 to the servo object
myservo.write(init_pos);
}

void loop() {
  // put your main code here, to run repeatedly:
if (button() == true){
  Serial.println("TRUE");
}
}


boolean button(){
  int reading = digitalRead(buttonPin);
  if (reading != lastButtonState){  //If the button state changed, start a timer
    lastDebounceTime = millis();
  }
  if ((millis() - lastDebounceTime) > debounceDelay) {
    if (reading != buttonState){
      buttonState = reading;
      return true; 
     }
    else{
      return false;
    }
  }
  lastButtonState = reading;
}
2

if (reading != buttonState && reading == HIGH){

3

LarryD:
if (reading != buttonState && reading == HIGH){

Naw, he'll need a second if, because he wants to set buttonState = reading regardless of whether the button was pressed or released, but he only wants to return true if it was pressed.

4

Oops

5 
#include <Servo.h>

Servo myservo;

int init_pos = 90; //Positions for servo to sort nuts
int pos1 = 30;
int pos2 = 70;
int pos3 = 110;
int pos4 = 150;

int buttonPin = 8; //Variables for push button
int buttonState = LOW;
int lastButtonState = LOW;
unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 50;



void setup() {
  // put your setup code here, to run once:

Serial.begin(9600);
pinMode(buttonPin, INPUT_PULLUP); 

myservo.attach(9);  // attaches the servo on pin 9 to the servo object
myservo.write(init_pos);
}

void loop() {
  // put your main code here, to run repeatedly:
if (button() == true){
  Serial.println("TRUE");
}
}


boolean button(){
  int reading = digitalRead(buttonPin);
  if (reading != lastButtonState){  //If the button state changed, start a timer
    lastDebounceTime = millis();
  }
  
  if ((millis() - lastDebounceTime) > debounceDelay) {
    if (reading != buttonState){
      buttonState = reading;
      if(reading == LOW) //for push = LOW     OR     if(reading == HIGH) //for push = HIGH
      {
      return true; 
      }
     }
    //else{
      return false;
    //}
  }
  lastButtonState = reading;
}
6

Saving the current state as the previous state happens only at the end of the function. The end of the function is never reached, because a return statement has already been executed.

That debounce functions sucks.