#include <Servo.h> //Include the library Servo.

#define resetRFID 13 //Define reset RFID as 13
#define gate 8 //Define gate as 8

String tag_read = "0000000000000"; //Creates the variable tag_read and "clean" the positions of ID
String tag_CARD = "0B00487A7A43"; //Creates the variable tag_CARD with an ID of the Card

int i; //Variable to count
int position=90; //Starts with the initial value of the position of servomotor (90 degrees, closed gate)

Servo servo; //Instance the library Servo.

void setup()
{

Serial.begin(9600); //Initiates the serial with baud rate of 9600

pinMode(resetRFID, OUTPUT); //Sets the pin D13 as an output
servo.attach(gate); //Sets the pin D8 to be used with the servomotor
servo.write(position); //Positions the cursor of the servomotor to the first position (90 degrees);

digitalWrite(resetRFID, LOW); //Places the reset pin of ID12/20 module in low level (resetRFID, LOW);
delay(5); //Wait 5 milliseconds
digitalWrite(resetRFID, HIGH); //Places the reset pin of ID12/20 module in high level (resetRFID, HIGH);
delay(5); //Wait 5 milliseconds

}

void loop ()
{

if(Serial.available() > 0) //If the serial receive data (ID)
{

le_tag(); //Execute the function of the TAG read
identifies_tag(); //Identifies which TAG this ID belongs (Card or Capsule)
clean_tag(); //Execute the function to clean the ID and reset the ID 12/20 module
}

delay(100); //Wait 100 milliseconds

}

void le_tag() //Funcition that reads the TAG and store the ID's TAG in a variable tag_read
{

i=0; //Resets the variable to read
while(Serial.available() > 0) //While the serial receive data (ID)
{
tag_read[i] = Serial.read(); //Store the character that entered in serial on tag_read’s position
i++; //Increments a variable of count

}

Serial.print("\n\nTAG Read:"); //Jump 2 lines and print at serial the phrase"TAG Read:"

for(i=0;i<13;i++) Serial.print(tag_read[i]); //Take each position of ID and print at the same serial
Serial.println(); //Jump a line at serial

}

void clean_tag() //Function that cleans the variable tag_read and resets the module ID 12/20 for a new read leitura
{

digitalWrite(resetRFID, LOW); //Places the reset pin of ID12/20 module in low level (resetRFID, LOW);
delay(5); //Wait 5 milliseconds
digitalWrite(resetRFID, HIGH); //Places the reset pin of ID12/20 module in high level (resetRFID, HIGH);
delay(5); //Wait 5 milliseconds

for(i=0;i<13;i++) tag_read[i] = '0'; //Lace to clean all the positions of the variable tag_read

}

void identifies_tag() //Function that identifies the TAG
{

boolean validate = true; //Creates a boolean variable to validate the TAG

//Lace to compare the ID of the tag_read with the ID of the tag_CARD
for(i=0 ; i<13 ; i++)
{

if(tag_read[i+1] != tag_CARD[i]) // If ID tag_read is different from the ID tag_card
{
validate = false; //Invalidates the tag_CARD
}

}

//===========================================================

if(validate == true)//If the "tag CARD" is not invalidated
{

 //Changes the state of the Servo (Gate)
if(position != 90) //If the variable position is different of 90 degrees
{
position = 90; //Store the value 90 in the variable position
servo.write(position); //Positions the cursor of the servomotor at 90 degrees
Serial.println("CARD >> Open Cancel"); //Prints in the serial the phrase "CARD >> Open Cancel"
}

else if(position != 175) //If the variable position is different of 175 degrees
{
position = 175; //Store the value 175 in the variable position
servo.write(position); //Positions the cursor of the servomotor at 175 graus
Serial.println("CARD >> Close Cancel"); //Prints in the serial the phrase "CARD >> Close Cancel"

}

delay(2000); //Wait 2 seconds to make a new reading;
}

}