I'm trying to wire the mfrc522 and the huzzah but i can't seem to figure out the rst pin.

I found the pin out diagram but it doesn't show or idk how its labeled as. enter image description here

2 Answers 2


use Wemos table from your link. here is the mapping to esp8266 io pins

RST/Reset   D3 = io 0
SPI SS      D8 = io 15
SPI MOSI    D7 = io 13
SPI MISO    D6 = io 12
SPI SCK     D5 = io 14

If you want, you can use any pin for SS and reset. See the examples.

#define SS_PIN 4
#define RST_PIN 5
MFRC522 mfrc522(SS_PIN, RST_PIN);
  • @xiao-ning-er, did it help?
    – Juraj
    Jan 29, 2019 at 20:00

Use GPIO0 (D3 on the Wemos). The reset signal is under program control in the library and isn't the same as the ESP8266 reset input.


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