I'm working with a project in which I need to use an SD card module and an RFID antenna simultaneously. The devices that I'm using are the MFRC522 and the CATALEX SD Card Adapter. Both have SPI Protocol, and they're using the libraries MFRC522.h and SD.h.
This is the pin layout that I'm using:
/////// For RFID //////////
Arduino
Mega
Signal Pin
---------------------
RST/Reset 5
SPI SS 53 (CUSTOM)
SPI MOSI 51
SPI MISO 50
SPI SCK 52
//////// For SD ///////////
Arduino
Mega
Signal Pin
----------------------
SPI SS 49 (CUSTOM)
SPI MOSI 51
SPI MISO 50
SPI SCK 52
As you can see the only line that they are not sharing is the Slave Select (aside from the RST pin of the RC522 module), so I believe that my wiring is correct.
I tried setting in LOW the chip select of the device that I wanted to use and in HIGH the one that I didn't. But this didn't work.
Any help you could provide would be appreciated! Thanks!