ok, quick followup on this.
the values of the card are saved in an array, called RC522.serNum[i],HEX
this array has 5 values, 0 to 4.
now what i want to do is save this array to a single string, containing 10 HEX characters, so that i can compare the outcome to a valid card.
so what i tried is setting up a string and adding the values, but that was no good..
is there any way anyone can point me in the right direction ?
my end goals is to read a card, validate it's a valid card, then proceed to do an action based on this. (switch a relais).