Why do my buttons take so long to register

Other Hardware General Electronics
1

I'm having trouble with my buttons lagging or not registering when pressed. When I upload the following code my buttons need 3-4 clicks before they start to register and start doing what they're supposed to do. Any tips on how to fix this?

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 32

#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define height 128
#define width 32

#define button  D6   //digital pins 6 and 7 for my board. just put '6' and '7' for normal arduino boards.
#define button2  D7

int screen_current = 0;
int old_screen = 0;
int buttonPoll = 0; 
int button2Poll = 0; 


void setup() {

  Serial.begin(9600);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
    }

    display.begin(SSD1306_SWITCHCAPVCC, 0x3c);
    display.clearDisplay();     //clear the buffer
    display.display();
    pinMode(button, INPUT_PULLUP);
    pinMode(button2, INPUT_PULLUP);
}

void loop() {
    //debounce
    buttonPoll = digitalRead(button);
    if(buttonPoll == 1) {
      Serial.println("PRESSED");
      delay(50);
      buttonPoll = digitalRead(button);
      if(buttonPoll == 0) {
        screen_current = old_screen + 1;
        Serial.println("RELEASED");
      }
    }
    else{
      Serial.println("DO NOTHING");
      delay(50);
    }
    
    //debounce button 2
    button2Poll = digitalRead(button2);
    if(button2Poll == 1) {
      Serial.println("PRESSED");
       
      delay(50);
      button2Poll = digitalRead(button2);
      if(button2Poll == 0) {
        screen_current = old_screen - 1;
        Serial.println("RELEASED");
      }
    }
    else{
      Serial.println("DO NOTHING");
      delay(50);
    }

    switch(screen_current) {

      case 1:
        display.clearDisplay();
        display.setTextSize(2);
        display.setTextColor(WHITE);
        display.setCursor(30, 9);
        display.println("SCREEN 1");
        display.display();    
        Serial.println("SCREEN CURRENT = ");
        Serial.println(screen_current);
        Serial.println("OLD SCREEN = ");
        Serial.println(old_screen);
        old_screen = screen_current;
        break;
      case 2:
        display.clearDisplay();
        display.setTextSize(2);
        display.setTextColor(WHITE);
        display.setCursor(30, 9);
        display.println("SCREEN 2");
        display.display();    
        Serial.println("SCREEN CURRENT = ");
        Serial.println(screen_current);
        Serial.println("OLD SCREEN = ");
        Serial.println(old_screen);
        old_screen = screen_current;
        break;
      case 3:
        display.clearDisplay();
        display.setTextSize(2);
        display.setTextColor(WHITE);
        display.setCursor(30, 9);
        display.println("SCREEN 3");
        display.display();    
        Serial.println("SCREEN CURRENT = ");
        Serial.println(screen_current);
        Serial.println("OLD SCREEN = ");
        Serial.println(old_screen);
        old_screen = screen_current;
        break;
      default:
        display.clearDisplay();
        display.setTextSize(2);
        display.setTextColor(WHITE);
        display.setCursor(30, 9);
        display.println("SCREEN X");
        display.display();    
        old_screen = 0;
        Serial.println("SCREEN CURRENT = ");
        Serial.println(screen_current);
        Serial.println("OLD SCREEN = ");
        Serial.println(old_screen);
        break;
    }
}
2

Use conventional switch state detection and debounce logic, instead of the non-working logic you are using.

Investigate the switch example sketches that ship with the IDE.

3

Can you please elaborate?

4

There is no need. The tutorials and examples should get you on the right track. If not, come back. Did you write this code?

1 Like
5

Do you know which tutorial, in particular, I should look at? i followed a tutorial for this code and implemented it into my own project.

6

State change detection is a good one. There are several, you can access them directly from the examples menu in the IDE

7

I want to know this too

8

I followed a tutorial for this and implemented it into my own project for OLED. It only switches screens when I let go of the button.

9

So you didn't write it. Please provide a link to it.

10

Ok I'll look into State Chang Detection. Thanks for the help!

11

" Arduino Basics Handling Multiple States" on youtube by learnelectronics

12

Switch code is actually logically simple, but people often fail to research it, create crazy concoctions, and run with it because it half works.

13

Stay away from YT for microprocessor learning. It's 99% garbage.

1 Like
14

Ahh I see. would this solve the button lag if I implemented it into my code?

15

I see. Do you recommend any good learning resources?

16

All I can tell you, there is no button lag in my code, or the Arduino example code. There is a list of resources in the permanent threads at the top of the forum.''

Don't waste your time trying to fix this junk. Just learn how it works, then you will always know how to code it.

17

Ok thanks for the help. I'll look into the resources!

18

Sorry I didn't answer your question directly. It's just that the real answer is too long winded to post here.

19

I had a quick glance at your code and your debounce logic looked sketchy to me. All those delay() calls are blocking the loop.

20

How should I fix the delays without hindering the function of the code?