i’m new to this arduino world and i have a project for may class. i have an arduino mega 2560, high precision RTc sd+eth shield and wiegand keypad with rfid incorporated. i’m 90% done and working, the only problem i cant solve it right now, is that i dont know how to manage data very well. let me explain to you.
–i have 4 rfid cards
–i need to enroll 3 of them in the system, the card codes need to be saved in a file but i cant save the same code twice or more.
–the file is text
–when i aproach the rfid cards to the reader, i need to check the card code if its in the system
–if the code is corect i open the gate and log that card
my problem is:
–how do i save the card code only once?
–how do i delete that code if i want to remove it from the system?
–how do i check if the code is in the system?
i need help, any ideea pls