Hello. I have bought an Arduino UNO kit that came with an RFID module. I have soldered the pins on the RFID module, then I did the wiring. RFID Arduino RST 9 SDA(SS) 10 MOSI 11 MISO 12 SCK 13 GND GND 3.3V 3.3…

[image] codepirate7: Why is that? Because the pins of the RC522 are not 5V tolerant. See the data sheet for this chip and see if you can find if they are. If it is not mention then they aren't. It is unusual for a 3V3 chip to have 5V tolerant inputs and the manufacturers would brag about it o…

Does that module have the correct voltage-level adjustments to work with a 5V Arduino? See: [image] RFID RC522 malfunction multi scan Project Guidance If you wire up a RC522 to a 5V processor you need level shifters to protect the chip from the output signals from the 5V …

Thank you for answering me. But I don't get it, my Arduino has both 5V and 3.3V pins, and i'm using the 3.3V pin for te 3.3V on the module, do I still need to use resistors even though I'm connecting it to the 3.3V pin? Why is that? [ard0]

[image] codepirate7: my Arduino has both 5V and 3.3V pins, and i'm using the 3.3V Those are just the power supply pins - you also need to take care of the interface pins - see the follow-up post in that thread: [image] RFID RC522 malfunction multi scan Project Guidance …

Why is my RFID-RC522 module not working?

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awneil September 4, 2023, 12:24pm 2

Does that module have the correct voltage-level adjustments to work with a 5V Arduino?

See:

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RC522 RFID module powered but not scanning cards Sensors	3	175	March 14, 2026
MFRC RC522 not communicating with arduino uno General Guidance	18	1411	October 12, 2024
RC522 RFID Module not connecting General Guidance	5	175	March 31, 2026
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Why is my RFID-RC522 module not working?

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