how many Weigand26 readers it's possible to connect to Arduino UNO and Arduino Mega
Well it uses the pin change interrupt so number of readers = number of free pins / 2
And it's possible to "decode" the Card data like the other code I posted using your code as sample ?
I don't know, I never read the code past the Weagand comment and I knew what problems you were going to have. But Weagand is Weagand so there should be no incompatibility it is just a matter of gathering up the right bytes.