ButtonPoll.ino

/*************************************************************
  Blynk is a platform with iOS and Android apps to control
  ESP32, Arduino, Raspberry Pi and the likes over the Internet.
  You can easily build mobile and web interfaces for any
  projects by simply dragging and dropping widgets.

    Downloads, docs, tutorials: https://www.blynk.io
    Sketch generator:           https://examples.blynk.cc
    Blynk community:            https://community.blynk.cc
    Follow us:                  https://www.fb.com/blynkapp
                                https://twitter.com/blynk_app

  Blynk library is licensed under MIT license
  This example code is in public domain.

 *************************************************************

  This example shows how to monitor a button state
  using polling mechanism.

  App dashboard setup:
    LED widget on V1
 *************************************************************/

/* Comment this out to disable prints and save space */
#define BLYNK_PRINT Serial

/* Fill in information from Blynk Device Info here */
//#define BLYNK_TEMPLATE_ID           "TMPxxxxxx"
//#define BLYNK_TEMPLATE_NAME         "Device"
//#define BLYNK_AUTH_TOKEN            "YourAuthToken"


#include <SPI.h>
#include <Ethernet.h>
#include <BlynkSimpleEthernet.h>

int prevState = -1;
int currState = -1;
long lastChangeTime = 0;

void checkPin()
{
  // Invert state, since button is "Active LOW"
  int state = !digitalRead(2);

  // Debounce mechanism
  long t = millis();
  if (state != prevState) {
    lastChangeTime = t;
  }
  if (t - lastChangeTime > 50) {
    if (state != currState) {
      currState = state;
      Blynk.virtualWrite(V1, state);
    }
  }
  prevState = state;
}

void setup()
{
  // Debug console
  Serial.begin(9600);

  Blynk.begin(BLYNK_AUTH_TOKEN);

  // Make pin 2 default HIGH, and attach INT to our handler
  pinMode(2, INPUT_PULLUP);
}

void loop()
{
  Blynk.run();
  checkPin();
}