Not able to read pushbutton on rotary encoder

Other Hardware Sensors
1

I'm working with a rotary encoder (like the one at Rotary Encoder + Extras : ID 377 : $4.50 : Adafruit Industries, Unique & fun DIY electronics and kits) along with an Arduino Uno. I have the encoder portion of it working, but I'm struggling to get the push button worked out.

Taking the encoder out of the equation and just focusing on the push button, my wiring looks like this:

For my code, I started out with the standard Button sketch, changed the pin to 8, and added some print statements:

const int buttonPin = 8;     // the number of the pushbutton pin
const int ledPin =  13;      // the number of the LED pin

// variables will change:
int buttonState = 0;         // variable for reading the pushbutton status

void setup() {
    Serial.begin(115200);  // output
    
  // initialize the LED pin as an output:
  pinMode(ledPin, OUTPUT);      
  // initialize the pushbutton pin as an input:
  pinMode(buttonPin, INPUT);     
}

void loop(){
  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin);

  // check if the pushbutton is pressed.
  // if it is, the buttonState is HIGH:
  if (buttonState == HIGH) {     
    // turn LED on:    
    digitalWrite(ledPin, HIGH);
    Serial.println("PRESSED");
  } 
  else {
    // turn LED off:
    digitalWrite(ledPin, LOW);
    Serial.println("button is off");
  }
  
  delay(250);
}

When I run my sketch, it starts off fine and for a short time the results are correct - when the push button isn't pressed "button is off" is printed, and when pressed, "PRESSED" is printed, but after a few seconds, buttonState is always HIGH and "PRESSED" is continuously printed (even though the button isn't really pressed).

I've tried adding a resistor on the voltage, like:

...and on the ground, and on the data line as well, but get the same results. I've tried trouble-shooting this but am stumped. Any suggestions?

Thanks,

Jeff

EncoderButton_example1.png
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EncoderButton_example2.png
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2

Try wiring one side of the switch to ground and the other side of the switch to an input pin. Set the pinMode to INPUT_PULLUP (pinMode(pin, INPUT_PULLUP):wink: The switch will be LOW when pressed.

digin.jpg
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3

The setup that I usually use is the one pointed by groundfungus, without capacitor and with the pinMode setted as INPUT.

4

I think that you need to get out the ohmmeter and find out which terminals are the pushbutton's ("this is what's meant when somebody says, "Pin it out.")

5

groundfungus:
Try wiring one side of the switch to ground and the other side of the switch to an input pin. Set the pinMode to INPUT_PULLUP (pinMode(pin, INPUT_PULLUP):wink: The switch will be LOW when pressed.

Thanks groundfungus, that was exactly what I needed! I tried out that wiring and it worked great.

Thanks again,

Jeff