ESP32 Forum

Hi,

I'm having trouble connecting an RC522 rfid reader to my esp32 module. I have the esp32-Lora module from Heltec with the built-in Oled and lora functionality.

Here is the pin diagram for this module: And here is the diagram for the Rc522 However, I don't understand how I should wire the reader to the module as it is written in the diagram "Pins with an arrow are used by on-board lora or Oled. They must not be used for other purposes unless you know what you are doing!".

I tried a lot of different wiring, but could not get it to work.

Any help would be greatly appreciated!
Thanks

Since this modules can either work using SPI or I2C, why simply use the I2C bus shared with OLED ?
Simply attached the SDA/SCL pins.

I Have tried to connect to I2C bus on Wemos Lolin32 Oled Board that is pin no. 5, 4 (SDA/SCL) which is also shared with Oled as 5 and 4 is dedicated I2C pins on this board. But while I run the code It says MFRC22 in not connected properly.


I have also tried to connect the mfrc522 through SPI bus using pins as MOSI=13, MISO=12, SCK=14, SS=2, RST=0, it is working alone but not working while add Wifi library to it. Please Help me if It is possible in some other ways..!!