Vladimir Podhorsky - expander PCF8574 + LCD1602

/*
    Original code from webpage
    https://elger.org/wiki/projects/i2c_pcf8574_8bit_port_expander
    Modified for 8 inputs and outputs + show info at LCD1602
    (c)2020 Martin Blaha - elektronek.cz
*/

#include <Wire.h>
#include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

byte iInput=0;
byte iOutput=0;

void setup()
{
    Wire.begin();
    lcd.begin(16, 2);
    lcd.setCursor ( 0, 0 );
    lcd.print("Vyber vstupu");
}

void loop()
{
    Wire.requestFrom(33,1);// Begin transmission to PCF8574 with the buttons
    if(Wire.available())   // If bytes are available to be recieved
    {
        iInput = Wire.read();// Read a byte
    }

    if(iInput<255)         //If the value less than 255
    {
        lcd.setCursor ( 0, 1 );
        if (iInput==254) // P0
        {
            iOutput = 1;
            lcd.print("Vstup 1");
        };
        if (iInput==253) // P1
        {
            iOutput = 2;
            lcd.print("Vstup 2");
        };
        if (iInput==251) // P2
        {
            iOutput = 4;
            lcd.print("Vstup 3");
        };
        if (iInput==247) // P3
        {
            iOutput = 8;
            lcd.print("Vstup 4");
        };
        if (iInput==239) // P4
        {
            iOutput = 16;
            lcd.print("Vstup 5");
        };
        if (iInput==223) // P5
        {
            iOutput = 32;
            lcd.print("Vstup 6");
        };
        if (iInput==191) // P6
        {
            iOutput = 64;
            lcd.print("Vstup 7");
        };
        if (iInput==127) // P7
        {
            iOutput = 128;
            lcd.print("Vstup 8");
        };
    }
    Wire.beginTransmission(32);  //Begin transmission to PCF8574 (with the LEDs)
    Wire.write(iOutput);         //Send data to PCF8574 (with the LEDs)
    Wire.endTransmission();      //End Transmission to PCF8574 (with the LEDs)
}