My partner and I are both working with a PN512 and we trying to communicate with it via SPI.
While sending values, we have found a very weird issue maybe you can help us with.
We are sending all the data correctly. However, when we try to read them (after writting each one) we always get the registers' reset value.
We have checked the following items to discard possible failure causes:
- The SPI lines are working fine. We have checked SCK, MOSI, MISO and CS with an oscilloscope and all 4 are working as spected .
- The crystal is oscillating OK.
- SPI timing is OK.
- Address bit shifting and setting/clearing the command bit (read/write) is also correctly done.
- All physical pads are correctly soledered and routed in the board.
Do we have to configure any special PN512's register for us to be able to modify its registers? Is there something we are not doing/configuring prior to send all data?
Hope someone could help us.