Code:
/*
* Made by KinCony IoT: https://www.kincony.com
*
* This program reads 32 input states from three PCF8575 I/O expanders and
* controls a corresponding 32-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
PCF8575:U27 (relay17-32) i2c address:0x25
PCF8575:U23 (DI1-16) i2c address:0x24
PCF8575:U49 i2c address: 0x26
PCF8575(pin number0-7):DI17-24
PCF8575(pin number8-11):relay13-16
PCF8575(pin number12-15):relay9-12
PCF8575:U62 i2c address: 0x27
PCF8575(pin number0-7):DI25-32
PCF8575(pin number8-15):relay1-8
*/
#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
#define INPUT_RELAY_I2C_ADDRESS_2 0x26
#define RELAY_I2C_ADDRESS_3 0x25
#define INPUT_RELAY_I2C_ADDRESS_3 0x27
PCF8575 pcf8575_IN1(INPUT_I2C_ADDRESS_1);
PCF8575 pcf8575_IN2(INPUT_RELAY_I2C_ADDRESS_2);
PCF8575 pcf8575_RL(RELAY_I2C_ADDRESS_3);
PCF8575 pcf8575_IN3(INPUT_RELAY_I2C_ADDRESS_3);
void setup() {
// Initialize I2C communication
Wire.begin(SDA, SCL);
// Initialize serial communication
Serial.begin(115200);
// Initialize input and relay modules
pcf8575_IN1.begin();
pcf8575_IN2.begin();
pcf8575_IN3.begin();
pcf8575_RL.begin();
// Turn off all relays at the start (LOW means OFF)
for (int i = 8; i < 16; i++) {
pcf8575_IN2.write(i, HIGH);
}
for (int i = 0; i < 16; i++) {
pcf8575_RL.write(i, HIGH);
}
for (int i = 8; i < 16; i++) {
pcf8575_IN3.write(i, HIGH);
}
Serial.println("System started: Input state controlling 24 relays");
}
void loop() {
bool inputState;
inputState = pcf8575_IN1.read(0); // input1 control relay1
if (inputState) {
pcf8575_IN3.write(8, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN3.write(8, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN1.read(1); // input2 control relay2
if (inputState) {
pcf8575_IN3.write(9, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN3.write(9, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN1.read(2); // input3 control relay3
if (inputState) {
pcf8575_IN3.write(10, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN3.write(10, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN1.read(3); // input4 control relay4
if (inputState) {
pcf8575_IN3.write(11, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN3.write(11, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN1.read(4); // input5 control relay5
if (inputState) {
pcf8575_IN3.write(12, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN3.write(12, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN1.read(5); // input6 control relay6
if (inputState) {
pcf8575_IN3.write(13, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN3.write(13, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN1.read(6); // input7 control relay7
if (inputState) {
pcf8575_IN3.write(14, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN3.write(14, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN1.read(7); // input8 control relay8
if (inputState) {
pcf8575_IN3.write(15, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN3.write(15, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN1.read(8); // input9 control relay9
if (inputState) {
pcf8575_IN2.write(12, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN2.write(12, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN1.read(9); // input10 control relay10
if (inputState) {
pcf8575_IN2.write(13, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN2.write(13, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN1.read(10); // input11 control relay11
if (inputState) {
pcf8575_IN2.write(14, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN2.write(14, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN1.read(11); // input12 control relay12
if (inputState) {
pcf8575_IN2.write(15, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN2.write(15, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN1.read(12); // input13 control relay13
if (inputState) {
pcf8575_IN2.write(8, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN2.write(8, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN1.read(13); // input14 control relay14
if (inputState) {
pcf8575_IN2.write(9, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN2.write(9, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN1.read(14); // input15 control relay15
if (inputState) {
pcf8575_IN2.write(10, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN2.write(10, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN1.read(15); // input16 control relay16
if (inputState) {
pcf8575_IN2.write(11, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_IN2.write(11, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN2.read(0); // input17 control relay17
if (inputState) {
pcf8575_RL.write(0, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(0, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN2.read(1); // input18 control relay18
if (inputState) {
pcf8575_RL.write(1, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(1, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN2.read(2); // input19 control relay19
if (inputState) {
pcf8575_RL.write(2, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(2, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN2.read(3); // input20 control relay20
if (inputState) {
pcf8575_RL.write(3, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(3, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN2.read(4); // input21 control relay21
if (inputState) {
pcf8575_RL.write(4, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(4, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN2.read(5); // input22 control relay22
if (inputState) {
pcf8575_RL.write(5, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(5, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN2.read(6); // input23 control relay23
if (inputState) {
pcf8575_RL.write(6, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(6, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN2.read(7); // input24 control relay24
if (inputState) {
pcf8575_RL.write(7, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(7, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN3.read(0); // input25 control relay25
if (inputState) {
pcf8575_RL.write(8, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(8, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN3.read(1); // input26 control relay26
if (inputState) {
pcf8575_RL.write(9, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(9, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN3.read(2); // input27 control relay27
if (inputState) {
pcf8575_RL.write(10, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(10, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN3.read(3); // input28 control relay28
if (inputState) {
pcf8575_RL.write(11, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(11, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN3.read(4); // input29 control relay29
if (inputState) {
pcf8575_RL.write(12, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(12, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN3.read(5); // input30 control relay30
if (inputState) {
pcf8575_RL.write(13, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(13, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN3.read(6); // input31 control relay31
if (inputState) {
pcf8575_RL.write(14, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(14, LOW); // If input is LOW, turn the corresponding relay ON
}
inputState = pcf8575_IN3.read(7); // input32 control relay32
if (inputState) {
pcf8575_RL.write(15, HIGH); // If input is HIGH, turn the corresponding relay OFF
} else {
pcf8575_RL.write(15, LOW); // If input is LOW, turn the corresponding relay ON
}
// Delay for 500 milliseconds
delay(500);
}
