// Include the required Wire library for I2C
// Include the libraries:
// LiquidCrystal_I2C.h: https://github.com/johnrickman/LiquidCrystal_I2C
#include // Library for I2C communication
#include // Library for LCD

// Wiring: SDA pin is connected to A4 and SCL pin to A5.
// Connect to LCD via I2C, default address 0x27 (A0-A2 not jumpered)
LiquidCrystal_I2C lcd16x2_23 = LiquidCrystal_I2C(0x23, 16, 2); // Change to (0x23,16,2) for 16x2 LCD.
LiquidCrystal_I2C lcd20x4_27 = LiquidCrystal_I2C(0x27, 20, 4); // Change to (0x27,20,4) for 20x4 LCD.

#include
int x = 0;
int LED = 13;
int SlavePR[10] = {};

const int MOTOR=9; //Motor on Digital Pin 9

void HeartOfStainlessSteel_20x4_27() {
lcd20x4_27.init();
lcd20x4_27.backlight();

lcd20x4_27.setCursor(3, 0); // 4th column 1st row
lcd20x4_27.print("Welcome aboard");

lcd20x4_27.setCursor(8, 1); // 9th column 2nd row
lcd20x4_27.print("the");

lcd20x4_27.setCursor(6, 2); // 7th column 3rd row
lcd20x4_27.print("Heart of");

lcd20x4_27.setCursor(2, 3); // 3rd column 4th row
lcd20x4_27.print("Stainless Steel");
}

void LCD16x2_23() {
lcd16x2_23.init();
lcd16x2_23.backlight();

//PWM Simple Motor System

/* 
//LCD I2C 160X2_23

lcd16x2_23.setCursor(3, 0); // 4th column 1st row
lcd16x2_23.print("I am 0x23");
//LCD I2C 160X2_23
*/
}

void I2C_Begin() {
// I2C Scanner Code
Serial.begin(9600);
while (!Serial); // wait for serial monitor
Serial.println("\nI2C Scanner");
// I2C Scanner Code
}

void I2C_Find_Address() {
// I2C Scanner Code
byte error, address;
int nDevices;

Serial.println("Scanning...");

nDevices = 0;
for(address = 1; address < 127; address++ )
{
// The i2c_scanner uses the return value of
// the Write.endTransmisstion to see if
// a device did acknowledge to the address.
Wire.beginTransmission(address);
error = Wire.endTransmission();

if (error == 0)
{
Serial.print("I2C device found at address 0x");
if (address<16)
Serial.print("0");
Serial.print(address,HEX);
Serial.println(" !");

nDevices++;
}
else if (error==4)
{
Serial.print("Unknown error at address 0x");
if (address<16)
Serial.print("0");
Serial.println(address,HEX);
} 
}
if (nDevices == 0)
Serial.println("No I2C devices found\n");
else
Serial.println("done\n");

delay(5000); // wait 5 seconds for next scan
// I2C Scanner Code 
}

void setup() {

//PWM Simple Motor System
pinMode(9,OUTPUT);

// comment out to stop the I2C find address 
//I2C_Begin(); 
// comment out to stop the I2C find address

// These control the LCD displays
LCD16x2_23();
HeartOfStainlessSteel_20x4_27();

// I2C counter for LEDs 
pinMode (LED, OUTPUT);
// Start the I2C Bus as Master
Wire.begin();
Serial.begin(9600);
// I2C counter for LEDs 
}

void loop() {
//PWM Simple Motor System

for (int i=0; i<256; i++)
{
Serial.println(i);

analogWrite(MOTOR, i);
delay(10);
}
delay(500);

for (int i=255; i>=0; i--)
{
Serial.println(i); 
analogWrite(MOTOR,i);
delay(10);
}

analogWrite(MOTOR,0);
delay(4000);

//Slave 1: display Photoresistor to LCD 16x2 
Wire.requestFrom(1, 4);
SlavePR[1] = Wire.read();
// SlavePR[1] = map(SlavePR[1], 0, 255, 0, 1023);
// ValueA0 = map(ValueA0, 0, 1023, 0, 255);

Serial.print(SlavePR[1]);
lcd16x2_23.setCursor(0, 0);
lcd16x2_23.print("PR1:");
lcd16x2_23.setCursor(4, 0);
lcd16x2_23.print(SlavePR[1]);
lcd16x2_23.print(" ");
Serial.print("\n");

//Slave 2: display Photoresistor to LCD 16x2 
Wire.requestFrom(2, 4);
SlavePR[2] = Wire.read();
Serial.print(SlavePR[2]);
lcd16x2_23.setCursor(9, 0);
lcd16x2_23.print("PR2:");
lcd16x2_23.setCursor(13, 0);
lcd16x2_23.print(SlavePR[2]);
lcd16x2_23.print(" ");
Serial.print("\n");

//Slave 3: display Photoresistor to LCD 16x2 
Wire.requestFrom(3, 4);
SlavePR[3] = Wire.read();
Serial.print(SlavePR[3]);
lcd16x2_23.setCursor(0, 1);
lcd16x2_23.print("PR3:");
lcd16x2_23.setCursor(4, 1);
lcd16x2_23.print(SlavePR[3]);
lcd16x2_23.print(" ");
Serial.print("\n");

//Slave 4: display Photoresistor to LCD 16x2 
Wire.requestFrom(4, 4);
SlavePR[4] = Wire.read();
Serial.print(SlavePR[4]);
lcd16x2_23.setCursor(9, 1);
lcd16x2_23.print("PR4:");
lcd16x2_23.setCursor(13, 1);
lcd16x2_23.print(SlavePR[4]);
lcd16x2_23.print(" ");
Serial.print("\n");

// comment out to stop the I2C find address 
// I2C_Find_Address(); 
// comment out to stop the I2C find address

// I2C counter for LEDs 
x++; // Increment x

//From Left to Right
// First UNO
Wire.beginTransmission(1); // transmit to device #1
Wire.write(x); // sends x
Wire.endTransmission(); // stop transmitting

//Second UNO
Wire.beginTransmission(2); // transmit to device #2
Wire.write(x); // sends x
Wire.endTransmission(); // stop transmitting

//Mega in the Middle

//Third UNO
Wire.beginTransmission(3); // transmit to device #3
Wire.write(x); // sends x
Wire.endTransmission(); // stop transmitting

//Fourth UNO
Wire.beginTransmission(4); // transmit to device #4
Wire.write(x); // sends x
Wire.endTransmission(); // stop transmitting

if ( (x == 3) || (x == 6)) {
digitalWrite(LED, HIGH);
}
else {
digitalWrite(LED, LOW);
}

if (x == 7) x = 0; // `reset x once it gets 6
delay(1000);
// I2C counter for LEDs

}