HydraFW binary NFC Reader mode guide

This guide is updated towards firmware release HydraFW v0.10 and later

Commands

Once the NFC mode has been selected, the following commands are available :

• 0b00000000 Return to main mode. Returns BBIO1
• 0b00000001 Mode identification. Returns NFC1
• 0b00000010 Switch RF off
• 0b00000011 Switch RF on
• 0b00000100 Send bits (see below)
• 0b00000101 Send bytes (see below)
• 0b00000110 Set mode to ISO 14443A Reader
• 0b00000111 Set mode to ISO 15693 Reader
• 0b11xxxxxx Binary Auxiliary pins

Command details

Send bits (0b00000100)

This command is used to send at most 7 bits and read the response Format :

Byte 1           2          3
|----------|----------|----------|
 [command]    [bits]    [number]

number bits are sent starting from MSB of the bits field.

This commands returns one byte containing the number of bytes of the response, followed by the response.

Send bytes (0b00000101)

This command is used to send full bytes and read the response. Format :

Byte 1           2          3          4
|----------|----------|----------|----------| [...]
 [command]    [CRC]     [number]    [data]

If CRC == 0, the CRC is not calculated by the transceiver. if CRC == 1 CRC is calculated and transmitted.

data length has to match the number bytes to be sent.

This commands returns one byte containing the number of bytes of the response, followed by the response.

See https://github.com/hydrabus/hydrafw/wiki/HydraFW-HydraNFC-v1-guide for more explanation.