[arduino code examples for T16M]-02 Read digital input ports state by 9555 chip

Code:
/*

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

 *

 * Description:

 * This Arduino program reads 16 digital inputs from an XL9555

 * I/O expander using the PCA95x5 library.

 *

 * Input states are printed as a fixed-width 16-bit binary value:

 * - Leftmost bit:  CH16 (port 15)

 * - Rightmost bit: CH1  (port 0)

 * - 0 = ON

 * - 1 = OFF

 *

 * Pin Definitions:

 * - SDA: GPIO 11

 * - SCL: GPIO 12

 * - XL9555 I2C Address: 0x24

 *

 * Read Interval:

 * - 500 milliseconds

 */



#include <Arduino.h>

#include <Wire.h>

#include <PCA95x5.h>



// Define I2C pins and device address.

#define I2C_SDA      11

#define I2C_SCL      12

#define I2C_ADDRESS  0x24



// Use the PCA9555 driver for the XL9555 I/O expander.

PCA9555 inputIO;



void setup() {

    Serial.begin(115200);



    // Initialize I2C: SDA = GPIO11, SCL = GPIO12, clock = 100 kHz.

    Wire.begin(I2C_SDA, I2C_SCL, 100000);



    // Attach the XL9555 to the I2C bus.

    inputIO.attach(Wire, I2C_ADDRESS);



    // Read the original input levels without polarity inversion.

    inputIO.polarity(PCA95x5::Polarity::ORIGINAL_ALL);



    // Configure all 16 ports as inputs.

    inputIO.direction(PCA95x5::Direction::IN_ALL);



    delay(50);



    Serial.println("KinCony XL9555 16-channel input test");

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

    Serial.println("Bit order: CH16 ... CH1");

}



void loop() {

    // Read all 16 input ports.

    uint16_t state = inputIO.read();



    // Print all 16 bits, including leading zeros.

    Serial.print("Input state: ");



    for (int bit = 15; bit >= 0; bit--) {

        Serial.print((state >> bit) & 0x01);

    }



    Serial.println();



    delay(500);

}