Hi everyone! i am new in coding for arduino. I need some help with the project i’m working on. my project is a object tracking by using the rfid rc522 for inventory system. so i need to have multi reader in this project. i would like to have 4 reder that will work at the same time.
this is how i want my project to work:
there is going to be 3 or 4 reader rc522, 1 i2s lec and leds.
one rfid tag will be use as the master card. the master card have the ability to add or remove card.
when 1 tag is tapped on 1 reader, the card quantity at the reader that it tapped will increase. example when we tap the tag at reader1, reader1 will add 1 card into its memory.
hey, I did this before after a long search I found a good tutorial, with a master card that can add or remove other cards! the saved cards are stored in the eeprom of the arduino so that when you switch off the arduino everything stays stored!
here is the link to the tutorial:
here’s the code:
/*
* Arduino Door Lock Access Control Project
*
* by Dejan Nedelkovski, www.HowToMechatronics.com
*
* Library: MFRC522, https://github.com/miguelbalboa/rfid
*/
#include <SPI.h>
#include <MFRC522.h>
#include <LiquidCrystal.h>
#include <Servo.h>
#define RST_PIN 9
#define SS_PIN 10
byte readCard[4];
char* myTags[100] = {};
int tagsCount = 0;
String tagID = "";
boolean successRead = false;
boolean correctTag = false;
int proximitySensor;
boolean doorOpened = false;
// Create instances
MFRC522 mfrc522(SS_PIN, RST_PIN);
LiquidCrystal lcd(2, 3, 4, 5, 6, 7); //Parameters: (rs, enable, d4, d5, d6, d7)
Servo myServo; // Servo motor
void setup() {
// Initiating
SPI.begin(); // SPI bus
mfrc522.PCD_Init(); // MFRC522
lcd.begin(16, 2); // LCD screen
myServo.attach(8); // Servo motor
myServo.write(10); // Initial lock position of the servo motor
// Prints the initial message
lcd.print("-No Master Tag!-");
lcd.setCursor(0, 1);
lcd.print(" SCAN NOW");
// Waits until a master card is scanned
while (!successRead) {
successRead = getID();
if ( successRead == true) {
myTags[tagsCount] = strdup(tagID.c_str()); // Sets the master tag into position 0 in the array
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Master Tag Set!");
tagsCount++;
}
}
successRead = false;
printNormalModeMessage();
}
void loop() {
int proximitySensor = analogRead(A0);
// If door is closed...
if (proximitySensor > 200) {
if ( ! mfrc522.PICC_IsNewCardPresent()) { //If a new PICC placed to RFID reader continue
return;
}
if ( ! mfrc522.PICC_ReadCardSerial()) { //Since a PICC placed get Serial and continue
return;
}
tagID = "";
// The MIFARE PICCs that we use have 4 byte UID
for ( uint8_t i = 0; i < 4; i++) { //
readCard[i] = mfrc522.uid.uidByte[i];
tagID.concat(String(mfrc522.uid.uidByte[i], HEX)); // Adds the 4 bytes in a single String variable
}
tagID.toUpperCase();
mfrc522.PICC_HaltA(); // Stop reading
correctTag = false;
// Checks whether the scanned tag is the master tag
if (tagID == myTags[0]) {
lcd.clear();
lcd.print("Program mode:");
lcd.setCursor(0, 1);
lcd.print("Add/Remove Tag");
while (!successRead) {
successRead = getID();
if ( successRead == true) {
for (int i = 0; i < 100; i++) {
if (tagID == myTags[i]) {
myTags[i] = "";
lcd.clear();
lcd.setCursor(0, 0);
lcd.print(" Tag Removed!");
printNormalModeMessage();
return;
}
}
myTags[tagsCount] = strdup(tagID.c_str());
lcd.clear();
lcd.setCursor(0, 0);
lcd.print(" Tag Added!");
printNormalModeMessage();
tagsCount++;
return;
}
}
}
successRead = false;
// Checks whether the scanned tag is authorized
for (int i = 0; i < 100; i++) {
if (tagID == myTags[i]) {
lcd.clear();
lcd.setCursor(0, 0);
lcd.print(" Access Granted!");
myServo.write(170); // Unlocks the door
printNormalModeMessage();
correctTag = true;
}
}
if (correctTag == false) {
lcd.clear();
lcd.setCursor(0, 0);
lcd.print(" Access Denied!");
printNormalModeMessage();
}
}
// If door is open...
else {
lcd.clear();
lcd.setCursor(0, 0);
lcd.print(" Door Opened!");
while (!doorOpened) {
proximitySensor = analogRead(A0);
if (proximitySensor > 200) {
doorOpened = true;
}
}
doorOpened = false;
delay(500);
myServo.write(10); // Locks the door
printNormalModeMessage();
}
}
uint8_t getID() {
// Getting ready for Reading PICCs
if ( ! mfrc522.PICC_IsNewCardPresent()) { //If a new PICC placed to RFID reader continue
return 0;
}
if ( ! mfrc522.PICC_ReadCardSerial()) { //Since a PICC placed get Serial and continue
return 0;
}
tagID = "";
for ( uint8_t i = 0; i < 4; i++) { // The MIFARE PICCs that we use have 4 byte UID
readCard[i] = mfrc522.uid.uidByte[i];
tagID.concat(String(mfrc522.uid.uidByte[i], HEX)); // Adds the 4 bytes in a single String variable
}
tagID.toUpperCase();
mfrc522.PICC_HaltA(); // Stop reading
return 1;
}
void printNormalModeMessage() {
delay(1500);
lcd.clear();
lcd.print("-Access Control-");
lcd.setCursor(0, 1);
lcd.print(" Scan Your Tag!");
}
