Hi, everyone. Tried my hands on RFID technology. This is my reference: Arduino RFID Door Lock System with LCD Display - YouTube
My problem is this:
For the first few tries, it worked 3 times only on "Access granted" condition. Every time on every reset. On "Access denied", no problem. I can scan invalid cards/tags continuously and the loop still worked. Only after the true condition is met, and for just 3 times, then it wouldn't work.
However, when I tried it again later in the day, Access Granted only worked once and still no problem on access denied. What do you think is the problem?
This is their code:
//Viral Science www.viralsciencecreativity.com www.youtube.com/c/viralscience
//RFID Door Lock System
#include <Wire.h>
#include <SPI.h>
#include <MFRC522.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
#define SS_PIN 10
#define RST_PIN 9
#define LED_G 4 //define green LED pin
#define LED_R 5 //define red LED
#define BUZZER 2 //buzzer pin
#define lock 3
MFRC522 mfrc522(SS_PIN, RST_PIN); // Create MFRC522 instance.
int Btn = 6;
void setup()
{
Serial.begin(9600); // Initiate a serial communication
SPI.begin(); // Initiate SPI bus
mfrc522.PCD_Init(); // Initiate MFRC522
pinMode(LED_G, OUTPUT);
pinMode(LED_R, OUTPUT);
pinMode(BUZZER, OUTPUT);
noTone(BUZZER);
pinMode(Btn,INPUT);
pinMode(lock,OUTPUT);
Serial.println("Place your card on reader...");
Serial.println();
lcd.begin();
lcd.backlight();
lcd.clear();
lcd.setCursor(0,0); // column, row
lcd.print(" Scan Your RFID ");
lcd.setCursor(0,1); // column, row
lcd.print(" Door Locked ");
}
void loop()
{
if(digitalRead(Btn) == HIGH){
Serial.println("Access Granted");
Serial.println();
delay(500);
digitalWrite(LED_G, HIGH);
lcd.setCursor(0,1); // column, row
lcd.print(" Door Un-Locked ");
tone(BUZZER, 2000);
delay(100);
noTone(BUZZER);
delay(50);
tone(BUZZER, 2000);
delay(100);
noTone(BUZZER);
digitalWrite(lock,HIGH);
delay(3000);
digitalWrite(lock,LOW);
delay(100);
digitalWrite(LED_G, LOW);
lcd.setCursor(0,1); // column, row
lcd.print(" Door Locked ");
tone(BUZZER, 2000);
delay(100);
noTone(BUZZER);
delay(50);
}
// Look for new cards
if ( ! mfrc522.PICC_IsNewCardPresent())
{
return;
}
// Select one of the cards
if ( ! mfrc522.PICC_ReadCardSerial())
{
return;
}
//Show UID on serial monitor
Serial.print("UID tag :");
String content= "";
byte letter;
for (byte i = 0; i < mfrc522.uid.size; i++)
{
Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");
Serial.print(mfrc522.uid.uidByte[i], HEX);
content.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " "));
content.concat(String(mfrc522.uid.uidByte[i], HEX));
}
Serial.println();
Serial.print("Message : ");
content.toUpperCase();
if ((content.substring(1) == "33 E8 C2 14") || (content.substring(1) == "5C 94 21 4A")) //change here the UID of card/cards or tag/tags that you want to give access
{
Serial.println("Access Granted");
Serial.println();
delay(500);
digitalWrite(LED_G, HIGH);
lcd.setCursor(0,1); // column, row
lcd.print(" Door Un-Locked ");
tone(BUZZER, 2000);
delay(100);
noTone(BUZZER);
delay(50);
tone(BUZZER, 2000);
delay(100);
noTone(BUZZER);
digitalWrite(lock,HIGH);
delay(3000);
digitalWrite(lock,LOW);
delay(100);
digitalWrite(LED_G, LOW);
lcd.setCursor(0,1); // column, row
lcd.print(" Door Locked ");
tone(BUZZER, 2000);
delay(100);
noTone(BUZZER);
delay(50);
}
else
{
lcd.setCursor(0,1); // column, row
lcd.print("Invalid RFID Tag");
Serial.println(" Access denied");
digitalWrite(LED_R, HIGH);
tone(BUZZER, 1500);
delay(500);
digitalWrite(LED_R, LOW);
noTone(BUZZER);
delay(100);
digitalWrite(LED_R, HIGH);
tone(BUZZER, 1500);
delay(500);
digitalWrite(LED_R, LOW);
noTone(BUZZER);
delay(100);
digitalWrite(LED_R, HIGH);
tone(BUZZER, 1500);
delay(500);
digitalWrite(LED_R, LOW);
noTone(BUZZER);
lcd.setCursor(0,1); // column, row
lcd.print(" Door Locked ");
}
}
They originally used it on Nano, but I used Uno. When I press the reset button on Arduino Uno, it can work again. But once I scan a valid card/tag, it won't work on the second time now. Even if I scan an invalid card/tag afterwards.
Is it a power problem? Memory problem? Or something with my RFID reader? The cards/tags?
TIA
