Smart Home Automation Forum

Code 6: //The demo code is PCF8574-DI You can copy the code to your Arduino IDE

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);

}

[attachment=529]
[attachment=532]

Based of your schema, i2c address are another way around than in config above - which one is correct?
from schema; PCF8574 (0x22) ports IN D1...8 and (0x21) ports IN D9...16
https://www.kincony.com/download/KC868-A...ematic.pdf

You are right.

For KC868-A16

// Set i2c address for output
PCF8574 pcf8574_1(0x24); // channel 1-8 adress:100100
PCF8574 pcf8574_2(0x25); //channel 9-16 adress:100101

// Set i2c address for input
PCF8574 pcf8574_1(0x22); // channel 1-8 adress: 100010
PCF8574 pcf8574_2(0x21); //channel 9-16 adress: 100001

[attachment=533]

What is the reason to restrict 16 pins only for input and another 16pins only for output?
What happens if I configure certain output pin as input?
In my project I need more inputs and in Arduino boards pins can be configured without any limits.

because input pins have optocoupler isolator. output pins connect with MOSFET.
how many input and output ports you will use?

KinCony Support

-Teme-

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schel4ok

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