[arduino code examples for AIO Hybrid]-02 Read digital input ports state

Code:
/*

 * Made by KinCony IoT: https://www.kincony.com

 *

 * Description:

 * This Arduino program continuously reads 12 digital inputs (P0~P11) 

 * from a PCF8575 I/O expander and prints their states to the Serial Monitor 

 * in binary format (0 = ON, 1 = OFF).

 *

 * Pin Definitions:

 * - SDA: GPIO 8

 * - SCL: GPIO 18

 * - PCF8575 I2C Address: 0x24

 */



#include <Arduino.h>

#include <Wire.h>

#include "PCF8575.h"



// I2C pin definitions

#define I2C_SDA 8

#define I2C_SCL 18



// PCF8575 object with I2C address 0x24

PCF8575 pcf8575_IN1(0x24);



void setup() {

    Serial.begin(115200);



    // Initialize I2C communication

    Wire.begin(I2C_SDA, I2C_SCL);



    // Initialize the PCF8575

    pcf8575_IN1.begin();



    Serial.println("Input state: 0=ON, 1=OFF");

}



void loop() {

    uint16_t state = 0;



    // Read the state of P0~P11

    for (int pin = 0; pin <= 11; pin++) {

        if (pcf8575_IN1.read(pin)) {

            state |= (1 << pin);

        }

    }



    // Print the state in binary format

    Serial.print("Input state: ");

    for (int pin = 11; pin >= 0; pin--) {

        Serial.print((state >> pin) & 1);

    }

    Serial.println();



    delay(500); // Polling delay

}