WARNING: Communication failure, is the MFRC522 properly connected?

So.....I have to buy a new one? :roll_eyes:

Domnulvlad:
So.....I have to buy a new one? :roll_eyes:

If you don't have used level shifters that would be an option. :wink:

pylon:
The soldering looks rather bad on the pictures.

In any way, connecting that board directly to an UNO might fry it.

On your picture none of the pins is labeled SS, so which pin did you use for SS?

I guess he was using SDA(SS) for SPI SS. I am having the same firmware error 0x0 (unknown).

Kindly assist.

Physical Layout

Soldering worked for me guys, thanks!

Hi there, I've encountered the similar problem as yours and I managed to solve it by welding the pins, so probally it's worth trying.