Hi everyone !
I have a problem with the SPI on the Arduino Uno board. Here my code for the MFRC522 RFID module, just read the Card ID and post to the serial port. It works perfectly but my next plan is use another spi slave, so I try to deactive the SPI slave's chip select with digitalWrite(chipSelectPin, HIGH) but it did not work. The module still can read the ID card.
How can i fix this. Thanks for any help !!!
ggrfid.ino (19.6 KB)