I'm trying to get the power consumption of a MFRC522 RFID module down, currently while running it consumes about 4mA. There should be a way to put it into sleep mode, I just can't find any documentation on it. I'm using the module with a arduino currently if that helps; and this is the module itself : MFRC522

1 Answer 1



Look at section 8.6.2 Soft power-down mode.

  • I still don't get how to implement this in my arduino code.
    – Sam W
    Commented Apr 14, 2015 at 19:03
  • First, that wasn't your question. Secondly, you didn't say how you connected it. Are you using SPI or UART? What library are you using?
    – Gerben
    Commented Apr 14, 2015 at 20:04
  • I didn't know there was anything other than an SPI library for it; but currently using SPI.
    – Sam W
    Commented Apr 15, 2015 at 1:27
  • Two questions, one answer. I'm done helping you.
    – Gerben
    Commented Apr 15, 2015 at 15:09
  • Sam, it sounds like you're asking two different questions: "How do I put the MFRC522 into sleep mode?" and "How do I send commands, such as the soft power-down command, from an Arduino to the MFRC522?". I suggest you open a separate, independent question to ask that second question, as recommended by meta.stackexchange.com/questions/39223/… .
    – David Cary
    Commented Sep 12, 2015 at 4:29

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