[Arduino IDE demo source code for KC868-A16]--#07-PCF8574-DI

Code:
#include "Arduino.h"

#include "PCF8574.h"



// Set i2c input address  

PCF8574 pcf8574_1(0x22,4,5);  // channel 1-8    address: 100010

PCF8574 pcf8574_2(0x21,4,5);  //channel 9-16    address: 100001







unsigned long timeElapsed;

void setup()

{

    Serial.begin(115200);

    delay(1000);

 pcf8574_1.pinMode(P0, INPUT);

 pcf8574_1.pinMode(P1, INPUT);

 pcf8574_1.pinMode(P2, INPUT);

 pcf8574_1.pinMode(P3, INPUT);

 pcf8574_1.pinMode(P4, INPUT);

 pcf8574_1.pinMode(P5, INPUT);

 pcf8574_1.pinMode(P6, INPUT);

 pcf8574_1.pinMode(P7, INPUT);



 pcf8574_2.pinMode(P0, INPUT);

 pcf8574_2.pinMode(P1, INPUT);

 pcf8574_2.pinMode(P2, INPUT);

 pcf8574_2.pinMode(P3, INPUT);

 pcf8574_2.pinMode(P4, INPUT);

 pcf8574_2.pinMode(P5, INPUT);

 pcf8574_2.pinMode(P6, INPUT);

 pcf8574_2.pinMode(P7, INPUT);



    Serial.print("Init pcf8574...");

    if (pcf8574_1.begin()){

        Serial.println("pcf8574_1_OK");

    }else{

        Serial.println("pcf8574_1_KO");

    }



  Serial.print("Init pcf8574...");

  if (pcf8574_2.begin()){

    Serial.println("pcf8574_2_OK");

  }else{

    Serial.println("pcf8574_2_KO");

  }



 

}



void loop()

{

 uint8_t val1 = pcf8574_1.digitalRead(P0);

 uint8_t val2 = pcf8574_1.digitalRead(P1);

 uint8_t val3 = pcf8574_1.digitalRead(P2);

 uint8_t val4 = pcf8574_1.digitalRead(P3);

 uint8_t val5 = pcf8574_1.digitalRead(P4);

 uint8_t val6 = pcf8574_1.digitalRead(P5);

 uint8_t val7 = pcf8574_1.digitalRead(P6);

 uint8_t val8 = pcf8574_1.digitalRead(P7);



 uint8_t val9 = pcf8574_2.digitalRead(P0);

 uint8_t val10 = pcf8574_2.digitalRead(P1);

 uint8_t val11 = pcf8574_2.digitalRead(P2);

 uint8_t val12 = pcf8574_2.digitalRead(P3);

 uint8_t val13 = pcf8574_2.digitalRead(P4);

 uint8_t val14 = pcf8574_2.digitalRead(P5);

 uint8_t val15 = pcf8574_2.digitalRead(P6);

 uint8_t val16 = pcf8574_2.digitalRead(P7);

  

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

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

 if (val3==LOW) Serial.println("KEY3 PRESSED");

 if (val4==LOW) Serial.println("KEY4 PRESSED");

 if (val5==LOW) Serial.println("KEY5 PRESSED");

 if (val6==LOW) Serial.println("KEY6 PRESSED");

 if (val7==LOW) Serial.println("KEY7 PRESSED");

 if (val8==LOW) Serial.println("KEY8 PRESSED");



 if (val9==LOW) Serial.println("KEY1 PRESSED");

 if (val10==LOW) Serial.println("KEY2 PRESSED");

 if (val11==LOW) Serial.println("KEY3 PRESSED");

 if (val12==LOW) Serial.println("KEY4 PRESSED");

 if (val13==LOW) Serial.println("KEY5 PRESSED");

 if (val14==LOW) Serial.println("KEY6 PRESSED");

 if (val15==LOW) Serial.println("KEY7 PRESSED");

 if (val16==LOW) Serial.println("KEY8 PRESSED");

 delay(300);

}