[arduino code examples for F24]-11 digital INPUT trigger OUTPUT directly

Code:
/*

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

 *

 * This program reads 24 input states from two PCF8575 I/O expanders and 

 * controls a corresponding 24-channel relay module. 

 * When an input pin is LOW, the corresponding relay is turned ON (LOW means ON for the relay).

 * When the input pin is HIGH, the corresponding relay is turned OFF.

 *

 * Pin Definitions:

 * - SDA: GPIO 8

 * - SCL: GPIO 18

 * - Input I2C Address 1 (inputs 1-16): 0x24

 * - Input/Relay I2C Address 2 (inputs 17-24 and relays 1-8): 0x26

 * - Relay I2C Address 3 (relays 9-24): 0x25

 */



#include <Wire.h>        // I2C communication

#include <PCF8575.h>     // Library to control the PCF8575 I/O expander



// Define I2C pins

#define SDA 8            // SDA pin

#define SCL 18           // SCL pin



// I2C addresses for the PCF8575 modules

#define INPUT_I2C_ADDRESS_1 0x24   // I2C address for the first input PCF8575 module (inputs 1-16)

#define INPUT_RELAY_I2C_ADDRESS_2 0x26   // I2C address for inputs 17-24 and relays 1-8

#define RELAY_I2C_ADDRESS_3 0x25   // I2C address for relays 9-24



PCF8575 pcf8575_IN1(INPUT_I2C_ADDRESS_1);    // Create an object for the first input PCF8575 (inputs 1-16)

PCF8575 pcf8575_IN2(INPUT_RELAY_I2C_ADDRESS_2);    // Create an object for the second input PCF8575 (inputs 17-24 and relays 1-8)

PCF8575 pcf8575_RL(RELAY_I2C_ADDRESS_3);    // Create an object for the relay PCF8575 (relays 9-24)



void setup() {

  // Initialize I2C communication

  Wire.begin(SDA, SCL);

  

  // Initialize serial communication

  Serial.begin(115200);

  

  // Initialize input and relay modules

  pcf8575_IN1.begin();  // For inputs 1-16

  pcf8575_IN2.begin();  // For inputs 17-24 and relays 1-8

  pcf8575_RL.begin();   // For relays 9-24

  

  // Turn off all relays at the start (LOW means OFF)

  for (int i = 0; i < 8; i++) {

    pcf8575_IN2.write(i, LOW);  // Turn off relays 1-8

  }

  for (int i = 0; i < 16; i++) {

    pcf8575_RL.write(i, LOW);  // Turn off relays 9-24

  }



  Serial.println("System started: Input state controlling 24 relays");

}



void loop() {

  // Read and control relays 1-16

  for (int i = 0; i < 16; i++) {

    bool inputState = pcf8575_IN1.read(i);  // Read input i from the first input module

    if (inputState) {

      pcf8575_RL.write(i, HIGH);  // If input is HIGH, turn the corresponding relay OFF

    } else {

      pcf8575_RL.write(i, LOW);   // If input is LOW, turn the corresponding relay ON

    }

  }



  // Read and control relays 17-24 (shared with second input module)

  for (int i = 0; i < 8; i++) {

    bool inputState = pcf8575_IN2.read(i + 8);  // Read input 17-24 from the second input module (pins 8-15)

    if (inputState) {

      pcf8575_IN2.write(i, HIGH);  // If input is HIGH, turn the corresponding relay OFF (1-8)

    } else {

      pcf8575_IN2.write(i, LOW);   // If input is LOW, turn the corresponding relay ON (1-8)

    }

  }



  // Delay for 500 milliseconds

  delay(500);

}