Hello

I have project with arduino IDE program that used C language ... Im using Arduino Uno and RFID RC522 to read a card .. this project work when I scan the card on reader ... So, now I have a code but I need to explaination to know how its work ?

// why we need this library ??

#include #include // why define this pin only? ( RFID RC522 has 8 pins) #define SS_PIN 10 #define RST_PIN 9 MFRC522 mfrc522(SS_PIN, RST_PIN);

//The card_ID[4] used for what ? And why the card write in this method {0x56,0x4d,0x47,0xFF} ?

byte card_ID[4]; byte First_card_ID[4]={0x56,0x4d,0x47,0xFF}; byte i; // why using the Boolean and why its false ? boolean State = false;

Void setup {

Serial.begin(9600); SPI.begin(); mfrc522.PCD_Init(); }

// I need explaining to how this function done step by step

void crd_id(){ for (byte i = 0; i < mfrc522.uid.size; i++) { if(card_ID[i]==First_card_ID[i]){ State=true; } else{ State=false; i=5; } } }

Finally, I want to add another card that can be read card and accepted

Regards,