LCD RF ID reader

In this project, I used the Elegoo templates for LCD display- specifically Hello World, along with the RFID template for changing out an ID on a card. Though the provided cards from the kit I was using does not allow for writing, I was able to read them and determine them to have 2 IDs. Using this information, I was able to make the LCD display if there's an acceptable card is placed to it or not. This is a small version of a verification system.

 

#include <SPI.h> #include <MFRC522.h> #include <LiquidCrystal.h> // initialize the library with the numbers of the interface pins LiquidCrystal lcd(7, 8, 9, 10,5, 4); #define RST_PIN 3 // Configurable, see typical pin layout above #define SS_PIN 6 // Configurable, see typical pin layout above MFRC522 mfrc522(SS_PIN, RST_PIN); // Create MFRC522 instance /* Set your new UID here! */ #define NEW_UID {0xDE, 0xAD, 0xBE, 0xEF} byte cardUID[4] = {0x7B, 0x20, 0xF9, 0x3};// blue thing is 53, FC, E6, 2C MFRC522::MIFARE_Key key; void setup() { Serial.begin(9600); // Initialize serial communications with the PC while (!Serial); // Do nothing if no serial port is opened (added for Arduinos based on ATMEGA32U4) SPI.begin(); // Init SPI bus mfrc522.PCD_Init(); // Init MFRC522 card // Prepare key - all keys are set to FFFFFFFFFFFFh at chip delivery from the factory. for (byte i = 0; i < 6; i++) { key.keyByte[i] = 0xFF; } // set up the LCD's number of columns and rows: lcd.begin(16, 2); // Print a message to the LCD. lcd.print("Card to Reader"); } // But of course this is a more proper approach void loop() { bool match = true; // Look for new cards, and select one if present if ( ! mfrc522.PICC_IsNewCardPresent() || ! mfrc522.PICC_ReadCardSerial() ) { // (note: line 1 is the second row, since counting begins with 0): lcd.setCursor(0, 1); // print the number of seconds since reset: lcd.print("NO CARD "); } else{ for (byte i = 0; i < 4; i++) { if (mfrc522.uid.uidByte[i] != cardUID[i]) { match = false; } } if(match){ lcd.setCursor(0, 1); lcd.print("Allowed! "); } if(!match){ lcd.setCursor(0, 1); lcd.print("NOT Allowed! "); } delay(2000); } /* just checking the id when needed Serial.print("UID: "); for (byte i = 0; i < mfrc522.uid.size; i++) { Serial.print(mfrc522.uid.uidByte[i], HEX); Serial.print(" "); } Serial.println(); delay(2000); */ }