Problem with digitalRead for simple buttons

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yeti86

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Hello!

I try to make a controller for a CNC machine, for that i need to emulate Numpad keys, i wired up a simple project box, used some knobs, switches etc. and soldered them together. all components are wired to the same ground together, and each other terminal goes to a different pin, from PIN1 - Pin 10, so total of 10 keys i like to use.

This is how my code looks like:

Code: 
#include <Keyboard.h>
void setup() {
  pinMode(1, INPUT);
  pinMode(2, INPUT);
  pinMode(3, INPUT);
  pinMode(4, INPUT);
  pinMode(5, INPUT);
  pinMode(6, INPUT); 
  pinMode(7, INPUT);
  pinMode(8, INPUT);
  pinMode(9, INPUT);
  pinMode(10, INPUT); 
  Keyboard.begin();
}
void loop() {
  if (digitalRead(0) == HIGH) {Keyboard.press(KEYPAD_2); Keyboard.release(KEYPAD_2);}
  if (digitalRead(1) == HIGH) {Keyboard.press(KEYPAD_1); Keyboard.release(KEYPAD_1);}
  if (digitalRead(2) == HIGH) {Keyboard.press(KEYPAD_3); Keyboard.release(KEYPAD_3);}
  if (digitalRead(3) == HIGH) {Keyboard.press(KEYPAD_7);  Keyboard.release(KEYPAD_7);}
  if (digitalRead(4) == HIGH) {Keyboard.press(KEYPAD_9);  Keyboard.release(KEYPAD_9);}
  if (digitalRead(5) == HIGH) {Keyboard.press(KEY_PAGE_UP);  Keyboard.release(KEY_PAGE_UP);}
  if (digitalRead(6) == HIGH) {Keyboard.press(KEY_PAGE_DOWN);  Keyboard.release(KEY_PAGE_DOWN);}
  if (digitalRead(7) == HIGH) {Keyboard.press(KEY_3); Keyboard.release(KEY_3);}
  if (digitalRead(8) == HIGH) {Keyboard.press(KEY_4); Keyboard.release(KEY_4);}
  if (digitalRead(9) == HIGH) {Keyboard.press(KEY_5); Keyboard.release(KEY_5);}
 
}


now the issue is that i get a irradical behavior, like the buttons keep pushing. I tried to change high to low too, same result. It should be Low for shortcircute between ground and pin?
I have removed all the pins once, and still it happens with both read states....

did i fry my board? it worked when i last did it for a flight controller, and now it doesn't work anymore.

Thanks for any suggestions :/ ;)
 
oh i see, INPUT_PULLUP is better as it uses the build in pullup resistors.... and than using fallingEdge() instead of digitalRead....
 
And still then, there is a risk of multiple events with one button press, due to mechanical contact bounce/chatter. You need a de-bounce algorithm for each button. The Bounce library could be of great help.
 
Highly recommend you start from the Buttons example.

In Arduino, click File > Examples > Teensy > USB_Keyboard > Buttons
 
It worked, alltho the relais do not work, it seams that he don't trigger the pins.... but i'll have a look tomorrow when my new multimeter arrives...

thanks, here is the code, for anyone who looks this up later by searching:

Code: 
#include <Bounce.h>

Bounce button0 = Bounce(0, 20);
Bounce button1 = Bounce(1, 20);
Bounce button2 = Bounce(2, 20);
Bounce button3 = Bounce(3, 20);
Bounce button4 = Bounce(4, 20);
Bounce button5 = Bounce(5, 20); 
Bounce button6 = Bounce(6, 20);
Bounce button7 = Bounce(7, 20); 
Bounce button8 = Bounce(8, 20);
Bounce button9 = Bounce(9, 20);
Bounce button10 = Bounce(10, 20);
Bounce button13 = Bounce(13, 100);
Bounce button14 = Bounce(14, 100);


void setup() {

  pinMode(0, INPUT_PULLUP);
  pinMode(1, INPUT_PULLUP);
  pinMode(2, INPUT_PULLUP);
  pinMode(3, INPUT_PULLUP);
  pinMode(4, INPUT_PULLUP);
  pinMode(5, INPUT_PULLUP);
  pinMode(6, INPUT_PULLUP);
  pinMode(7, INPUT_PULLUP);
  pinMode(8, INPUT_PULLUP);
  pinMode(9, INPUT_PULLUP);
  pinMode(10, INPUT_PULLUP);
  pinMode(13, OUTPUT);
  pinMode(14, OUTPUT);
}

void loop() {
  button0.update();
  button1.update();
  button2.update();
  button3.update();
  button4.update();
  button5.update();
  button6.update();
  button7.update();
  button8.update();
  button9.update();
  button10.update();

  if (button1.fallingEdge()) {
    Keyboard.press(KEY_2);
  }
  if (button2.fallingEdge()) {
    Keyboard.press(KEYPAD_4);
  }
  if (button3.fallingEdge()) {
    Keyboard.press(KEYPAD_6);
  }
  if (button4.fallingEdge()) {
    Keyboard.press(KEYPAD_2);
  }
  if (button5.fallingEdge()) {
    Keyboard.press(KEYPAD_8);
  }


  if (button7.fallingEdge()) {
    Keyboard.press(KEY_PAGE_DOWN);
  }
  if (button8.fallingEdge()) {
    Keyboard.press(KEY_PAGE_UP);
  }
  if (button9.fallingEdge()) {
    Keyboard.press(KEY_4);
  }
    if (button10.fallingEdge()) {
    Keyboard.press(KEY_3);
  }
  
  if (button13.fallingEdge()) {        //spindle active
  digitalWrite(13, HIGH);
  }
  if (button14.fallingEdge()) {
  digitalWrite(14, HIGH);                       //LED ON
  }

  // ---------------------------------------

  if (button1.risingEdge()) {
    Keyboard.release(KEY_2);
  }
  if (button2.risingEdge()) {
    Keyboard.release(KEYPAD_4);
  }
  if (button3.risingEdge()) {
    Keyboard.release(KEYPAD_6);
  }
  if (button4.risingEdge()) {
    Keyboard.release(KEYPAD_2);
  }
  if (button5.risingEdge()) {
    Keyboard.release(KEYPAD_8);
  }
  if (button7.risingEdge()) {
    Keyboard.release(KEY_PAGE_DOWN);
  }
  if (button8.risingEdge()) {
    Keyboard.release(KEY_PAGE_UP);
  }
  if (button9.risingEdge()) {
    Keyboard.release(KEY_4);
  }
  if (button10.risingEdge()) {
    Keyboard.release(KEY_3);
  }

  if (button13.risingEdge()) {        //spindle inactive
  digitalWrite(13, LOW);
  }
  if (button14.risingEdge()) {
  digitalWrite(14, LOW);                      //LED ON
  }

}
 
Code: 
Bounce button13 = Bounce(13, 100);
Bounce button14 = Bounce(14, 100);
.
.
.
  pinMode(13, OUTPUT);
  pinMode(14, OUTPUT);
You've declared pins 13 and 14 to be outputs so they can't be buttons as well.

Pete
 
el_supremo said:
Code: 
Bounce button13 = Bounce(13, 100);
Bounce button14 = Bounce(14, 100);
.
.
.
  pinMode(13, OUTPUT);
  pinMode(14, OUTPUT);
You've declared pins 13 and 14 to be outputs so they can't be buttons as well.

Pete
Click to expand...

*facepalm*

thanks, that was it
 
The LED on pin 13 sometimes interferes with buttons. The internal pullups are too weak to reliably pull it high, due to the loading of the LED. This can work if you use a real (and rather strong) pullup resistor, with a value like 470 ohms. But best to just avoid pin 13 and use other pins.
 
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