Using two PCF8574s for DI and DO

[mafckz]

How to use two PCF8574s for DI and DO both?

Next program works correctly when I use only one PCF8574 (adress: 0x22; I2C pins: 4,15) that controls DI inputs on the board:
1.png
   

But it doesn't work when I uncomment code in red frames, trying to add another PCF8574 (adress: 0x24; I2C pins: 4,15) that controls DO outputs on the board.
2.png
   



Correct code for using digital input PCF8574 without errors   "1.png"

Code:

// Library: PCF8574_Library by RENZO MISCHIANTI
// https://mischianti.org/2019/01/02/pcf8574-i2c-digital-i-o-expander-fast-easy-usage/


#include "Arduino.h"
#include "PCF8574.h"

// Set i2c address
PCF8574 pcf8574i(0x22,4,15);
// PCF8574 pcf8574(0x24,4,15);

unsigned long timelapsed;

void setup()
{
    Serial.begin(115200);
    delay(1000);

    pcf8574i.pinMode(0, INPUT);
    pcf8574i.pinMode(1, INPUT);

  // pcf8574.pinMode(0, OUTPUT);
  // pcf8574.pinMode(1, OUTPUT);
  // sleep(100);
  // pcf8574.digitalWrite(0, LOW);
  // pcf8574.digitalWrite(1, LOW);

  delay(2000);
    Serial.print("Init pcf8574i...");
    if (pcf8574i.begin()){
        Serial.println("OK");
    }else{
        Serial.println("KO");
    }
  // Serial.print("Init pcf8574...");
  //   if (pcf8574.begin()){
  //       Serial.println("OK");
  //   }else{
  //       Serial.println("KO");
  //   }
}

void loop()
{
    uint8_t val1 = pcf8574i.digitalRead(0);
    uint8_t val2 = pcf8574i.digitalRead(1);

    if (val1==LOW) Serial.println("KEY1 PRESSED");
    if (val2==LOW) Serial.println("KEY2 PRESSED");

  // if (val1==LOW) {
  //   Serial.println("KEY1 PRESSED");
  //   // pcf8574.digitalWrite(0, HIGH);
  // }
    // if (val2==LOW) {
  //   Serial.println("KEY2 PRESSED");
  //   // pcf8574.digitalWrite(1, HIGH);
  // }


  delay(100);
  // Serial.println("--");
}