I just bough 2 MFRC522 RFID reader from a different store. Both of them work well to read a standard 13.56 Mhz tags.
However, one of them have "MH" marking while the other doesnt. The one with MH marking able to read UID of a e-money card in my country (as of now I'm still looking for the tech detail of the card), while the other one cannot read it.
I try to swap the inductor (L1 and L2) between them and surprisingly, the original reader with MH marking now unable to read the e-money card, while the newly-swapped reader now able to read the e-money card.
Unfortunately, I dont have access to precise LC meter to measure the inductance of L1 and L2.
So, what is the different between MFRC522 with "MH" marking with others?
