Am working on a voting system. am using RFID and SD. when i connect the SD and the RFID. the rfid will not detect card but if i disconnect the SD the RFID will work perfectly... pls help a brother with the connection
Post links to the used hardware! A wiring diagram is probably also necessary.
This often happens which cheap Chinese SD readers which don't implement the SPI interface correctly (MISO should be tri-state if CS is HIGH).