I bought a bunch of the common RC522 boards from some Aliexpress vendor. They (I tried multiple) seem to work at the register read-write level, but they don't seem to execute commands, much less recognise any RFID card.
But the realy weird thing is that the version returns 0X12, which matches neither the rc522 1.0, nor the 2.0, nor the clone that should return 0x88.
I verfied with my scope that the chip indeed answers to the SPI byte 1110_1110 (read register 0x37) with the value 0001_0010. The signal is crips, no clock skew, nice sharp edges.
I tried this with and Arduino Uno, an Arduino Due, using a recent version of the miguelbalboa library. But as I see this on my scope, it can't see how it can be a software problem.
Has anyone seen this, or better: found a solution?