ESP8266 Community Forum

Hi everyone,

I have been trying to get my ESP8266 work with RC522 RFID module but it was not working when i connected 3.3v pin of the RC522 to the regulated 3v pin of the ESP8266.

So, after some reasearch I found VIN pin has unregulated 5v. When I assigned it to the 3.3v pin of the RC522 it started working fine!

Now my question is if i use a 5v usb power adapter to power the ESP8266 and have the RC522 powered through the vin pin is there any cause of concern ?

As far as I have read RC522 can take upto 5v. I belive the ESP8266 is supplying 3v instead of 3.3v which is required by the RC522, that is why it may have not been working. Now, its working when powered via VIN pin but is it safe? Or should I some how try to regulate to 3.3v.

Hardware used:
- NodeMCU v3 CH340g
- RC 522

Thanks in advance for the help. Sorry about the long explanation as you can guess, I am totally new to this.

Regards

Faisal

Yes, ESP8266 is supplying 3V. But from the tutorials that I came across it looks like the 3V supplied by the ESP is enough for the RFID module. This one says in case of some versions, the 5V Vin pin must be used. Check the warning here:

https://www.aranacorp.com/en/using-an-r ... n-esp8266/

However, if you got the 5V version of the RFID module, there should be no problem.

By the way, if you ever consider using Raspberry Pi instead, you can check this:

https://www.theengineeringprojects.com/ ... -pi-4.html