Hi,
I am using a ST25R3920 to emulate a type 2 tag. I have got the Read part working and I am able to send 16 bytes of data in response to 0x30 and confirm the data on a phone. But when the phone tries to write data using 0xA2, I am unable to send the 4 bit Ack (0xA) response that is acceptable for the phone which throws a write error. On probing the modulation using an oscilloscope, I noticed that the ST25 is sending
start 0101 0000 parity
instead of
start 0101 parity
Here is my send sequence:
Clear FIFO
Set ntx = 0, nbtx = 4 (to send only 4 bits)
Load FIFO with 0xA
Transmit without CRC
Is it possible to send 4 bit frames in card emulation mode with this chip to support type 2 communication?
