[arduino code examples for F24]-01 Turn ON/OFF relay by XL9555 chip

Code:
/*

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

 *

 * This program controls a 24-channel relay board via two XL9555SS I/O expanders.

 * It sequentially turns on each relay and then turns them off in a loop.

 * 

 * Pin Definitions:

 * - SDA: GPIO 8

 * - SCL: GPIO 18

 * 

 * Delay Time:

 * - 200 milliseconds between switching relays

 */



#include <Wire.h>        // Include the Wire library for I2C communication

#include <PCA95x5.h>     // XL9555SS I/O expander driver



#define SDA 8            // Define the SDA pin

#define SCL 18           // Define the SCL pin

#define DELAY_TIME 200   // Define the delay time in milliseconds



// Set I2C addresses of the XL9555SS modules

#define I2C_ADDRESS_R1 0x25 // I2C address of the first XL9555SS module

#define I2C_ADDRESS_R2 0x26 // I2C address of the second XL9555SS module



PCA9555 relayIO1; // Relays 9-24

PCA9555 relayIO2; // Relays 1-8



// XL9555SS port indices in physical relay order (1-8).

constexpr uint8_t RELAY_PORTS_1_TO_8[] = {12, 13, 14, 15, 8, 9, 10, 11};



void setup() {

  // Initialize I2C communication

  Wire.begin(SDA, SCL); // SDA on GPIO 8, SCL on GPIO 18 (according to your board's configuration)

  

  // Initialize serial communication for debugging (optional)

  Serial.begin(115200);

  Serial.println("XL9555SS Relay Control: Starting...");



  // Preload HIGH before enabling the active-low relay outputs.

  relayIO1.attach(Wire, I2C_ADDRESS_R1);

  relayIO1.write(PCA95x5::Level::H_ALL);

  relayIO1.polarity(PCA95x5::Polarity::ORIGINAL_ALL);

  relayIO1.direction(PCA95x5::Direction::OUT_ALL);



  relayIO2.attach(Wire, I2C_ADDRESS_R2);

  relayIO2.write(PCA95x5::Level::H_ALL);

  relayIO2.polarity(PCA95x5::Polarity::ORIGINAL_ALL);

  // Ports 0-7 remain inputs, and ports 8-15 drive relays 1-8.

  relayIO2.direction(0x00FF);

}



void loop() {

  // Sequentially turn on each relay (1-24)

  

  // Control relays 1-8 in physical channel order.

  for (uint8_t port : RELAY_PORTS_1_TO_8) {

    relayIO2.write(static_cast<PCA95x5::Port::Port>(port), PCA95x5::Level::L);

    delay(DELAY_TIME);          // Wait for DELAY_TIME milliseconds

  }



  // Then control the relays on the first XL9555SS (relays 9-24)

  for (int i = 0; i < 16; i++) {

    relayIO1.write(static_cast<PCA95x5::Port::Port>(i), PCA95x5::Level::L);   // Turn on the relay at pin i (LOW means ON for the relay)

    delay(DELAY_TIME);          // Wait for DELAY_TIME milliseconds

  }



  // Sequentially turn off each relay (1-24)

  

  // Control relays 1-8 in physical channel order.

  for (uint8_t port : RELAY_PORTS_1_TO_8) {

    relayIO2.write(static_cast<PCA95x5::Port::Port>(port), PCA95x5::Level::H);

    delay(DELAY_TIME);          // Wait for DELAY_TIME milliseconds

  }



  // Then control the relays on the first XL9555SS (relays 9-24)

  for (int i = 0; i < 16; i++) {

    relayIO1.write(static_cast<PCA95x5::Port::Port>(i), PCA95x5::Level::H);  // Turn off the relay at pin i (HIGH means OFF for the relay)

    delay(DELAY_TIME);          // Wait for DELAY_TIME milliseconds

  }

}