X-NUCLEO-NFC03A1 Send Receive Command not detecting RFID tag

[ClosedBridge]

Hello,

I'm using the X-NUCLEO-NFC03A1 dev kit with the CR95HF RFID chip. The protocol to talk to the chip I'm using is SPI, and the ISO configured is 15693. I can confirm SPI comms are working as both the ID and ECHO commands work. I also seem to get the correct response from the chip with the protocol is selected and configured for 15693. Unfortunately it seems like RFID tags are not getting detected. 

I can confirm the RFID tags are programmed and work as expected as I can used my phone's RFID scanner to detect the tag, and the protocol is detected to be 15693. I've attached a Saleae capture of the SPI comms between the MCU and the CR95HF when using a Send/Receive command. The error code that is returned by the CR95HF is 0x87, which corresponds to not detecting an RFID tag.

Currently I'm using the default 15693 protocol config of 0x00, but have tried lowering the protocol bit rate and waiting for SOF.

Help would be greatly appreciated!

Capture of configuring the protocol

Capture of Send/Receive Command

[ClosedBridge]

Hi Brian,

Sure thing, I added another log to the drive folder. The protocol select is the first transaction that appears, and succeeds towards the end of the transaction.

[Brian TIDAL · Accepted solution]

Hi Alex,

the ProtocolSelect 02 02 01 00 is configured to not append the CRC and therefore the frame are transmitted without CRC except if you manually add the CRC in the transmit buffer. As the CRC is missing, the tag ignores the received command.

I would suggest to use 02 02 01 0D for the ProtocolSelect. This should fix your issue.

Rgds

BT

[ClosedBridge]

Hi Brian,

Yes, this was indeed the problem. I am now able to receive the correct serial number from the tag!

Thanks again,

-Alex