WeMos D1 (esp8266): shield i2c per la gestione di encoder, pulsanti multipli e led

/*
 * PCF8574 Shield encoder and buttons
 * https://mischianti.org
 *
 * PCF8574    ----- WeMos
 * SDA        ----- D2(PullUp)
 * SCL        ----- D1(PullUp)
 * INT        ----- D7(PullUp)
 *
 * PCF8574 ----------------- Encoder
 * P0      ----------------- ENCODER PIN A
 * P1      ----------------- ENCODER PIN B
 * P2      ----------------- ENCODER BUTTON
 *
 */
#include "Arduino.h"
#include "PCF8574.h"
 
int encoderPinA = P0;
int encoderPinB = P1;
 
#define INTERRUPTED_PIN D7
 
void ICACHE_RAM_ATTR updateEncoder();
 
// initialize library
PCF8574 pcf8574(0x38, INTERRUPTED_PIN, updateEncoder);
 
volatile long encoderValue = 0;
uint8_t encoderButtonVal = HIGH;
 
void setup()
{
    Serial.begin (9600);
    delay(500);
 
    // encoder pins
    pcf8574.encoder(encoderPinA, encoderPinB);
    // encoder button
    pcf8574.pinMode(P2, INPUT_PULLUP);
 
    // Start library
    pcf8574.begin();
 
}
 
bool changed = false;
 
// The loop function is called in an endless loop
void loop()
{
    if (changed){
        Serial.print("ENCODER --> ");
        Serial.print(encoderValue);
        Serial.print(" - BUTTON --> ");
        Serial.println(encoderButtonVal?"HIGH":"LOW");
        changed = false;
    }
}
 
bool valPrec = LOW;
void updateEncoder(){
    changed = pcf8574.readEncoderValue(encoderPinA, encoderPinB, &encoderValue);
 
//  int vale = pcf8574.readEncoderValue(encoderPinA, encoderPinB);
//  if (vale!=0){
//      changed = true;
//  }
//  encoderValue = encoderValue + vale;
 
    bool val = pcf8574.digitalRead(P2);
    if (val!=valPrec){
      changed = true;
      valPrec = val;
      encoderButtonVal = val;
    }
}