#include <Wire.h>

const int deviceAddress = 0x68; // I2C address of the device (change as needed)
const uint8_t relay1 = 2; // LOW ACTIVE
const uint8_t relay2 = 3; // LOW ACTIVE
const uint8_t oe = 5;
const uint8_t d6 = 6; // Define pin D6
bool actionPerformed = false; // Flag to track if the action has been performed

void relaysOn()
{
    //Relays are low active
    digitalWrite(relay1,LOW);
    digitalWrite(relay2,LOW);
    delay(5);
}

void relaysOff()
{
    //Relays are low active
    digitalWrite(relay1,HIGH);
    digitalWrite(relay2,HIGH);
    delay(5);
}
// Function to transmit 16-bit data in little-endian format
void transmitData(uint8_t registerAddress, uint16_t data) {

    digitalWrite(oe,HIGH);
    Wire.beginTransmission(deviceAddress);
    Wire.write(registerAddress); // Send the register address
    Wire.write(data & 0xFF);      // Send the low byte (LSB)
    Wire.write((data >> 8) & 0xFF); // Send the high byte (MSB)
    Wire.endTransmission();
    digitalWrite(oe,LOW);
}

// Function to read back data from the register
uint16_t readData(uint8_t registerAddress) {
    uint16_t receivedData = 0;
    digitalWrite(oe,HIGH);
    // First, send the register address to read from
    Wire.beginTransmission(deviceAddress);
    Wire.write(registerAddress); // Send the register address
    Wire.endTransmission();

    if (Wire.endTransmission() != 0) {
    Serial.println("Device not found");
    digitalWrite(oe,LOW);
    return 0; // Return 0 or some error code
}
    
    // Now request 2 bytes from the device
    Wire.requestFrom(deviceAddress, 2);
    if (Wire.available() == 2) {
        receivedData |= Wire.read();       // Read low byte (LSB)
        receivedData |= Wire.read() << 8; // Read high byte (MSB)
    }
    digitalWrite(oe,LOW);
    return receivedData;
}

void setup() {
    Serial.begin(9600);
    Wire.begin(); // Initialize I2C
    pinMode(relay1, OUTPUT);
    pinMode(relay2, OUTPUT);
    pinMode(oe, OUTPUT);
    pinMode(d6, INPUT); // Set D6 as input
    digitalWrite(oe,LOW);

    for(int i = 8; i <= 13; i++)
    {
        pinMode(i,OUTPUT);
        digitalWrite(i,LOW);
    }
}

void printHex(uint16_t value) {
    Serial.print("0x");
    if (value < 0x10) {
        Serial.print("000");
    } else if (value < 0x100) {
        Serial.print("00");
    } else if (value < 0x1000) {
        Serial.print("0");
    }
    Serial.println(value, HEX); // Print the value in hexadecimal
}

unsigned long lastDebounceTime = 0; // Last time the pin state changed
unsigned long debounceDelay = 50;    // Debounce delay in milliseconds
int lastD6State = LOW;                // Last stable state of D6
int currentD6State;                   // Current state of D6

void loop() {
    // Read the current state of D6
    int reading = digitalRead(d6);

    // Check if the state has changed
    if (reading != lastD6State) {
        // Reset the debounce timer
        lastDebounceTime = millis();
    }

    // If the state has been stable for the debounce delay, update the state
    if ((millis() - lastDebounceTime) > debounceDelay) {
        // Only proceed if the state has changed
        if (reading != currentD6State) {
            currentD6State = reading;

            // Only act if the new state is HIGH and the action hasn't been performed yet
            if (currentD6State == HIGH && !actionPerformed) {
                relaysOn();                
                uint8_t registerAddress = 0xBF;
                uint16_t dataToSend = 0x0000;               
                // Transmit the data
                transmitData(registerAddress, dataToSend); // Transmit data
                // Read back data
                uint16_t receivedData = readData(registerAddress); // Read back data
                relaysOff();
                Serial.println("Received data : ");
                // Use the method to print received data in hexadecimal format
                printHex(receivedData); // Print formatted received data
                Serial.println(); // New line for better readability
                // Set the action performed flag to true
                actionPerformed = true;
            }
        }
    }

    // If the state is LOW, reset the action performed flag
    if (currentD6State == LOW) {
        actionPerformed = false;
    }

    // Update the last stable state
    lastD6State = reading;
}