How Emulate NDEF text with ST25R3916 (card emulation) ?

[Mickaël Bucher]

I Use STM32CubeExpansion_NFC6_V1.1.0 for emulate card with NUCLEO-L053R8 and X-NUCLEO-NFC06A1.

I Try NDEF URI card emulation with sucess.

I don't find a example code for NDEF Text emulation card.

Does anyone have a example code for NDEF Text Emulation card ?

Best Regards.

Mickaël

[Ulysses HERNIOSUS]

Hi Mickaël,

I think en.wikipedia.org/wiki/Android_Beam summarizes it quite well.

The size of an NDEF is not limited by ST25R3916. There may be some limits in our software (maybe in the 64K area). The NDEF specification would even allow to go beyond 2^32 bytes.

I think the real limit is more in the available RAM of the MCU and the transmission throughput which is often limited by an I2C bus on the smartphone. Nobody wants to tap a device for several minutes/hours/....

Regards, Ulysses

[Mickaël Bucher]

HI Ulysses,

I don't think the limits are my software.

If I understand the ST25R3916 datasheet, the RAM size is 48 bytes.

Can you confirm this point ?

Regards, Mickael

[Ulysses HERNIOSUS]

Hi Mickaël,

The 48 bytes which you are referring are for the static information used by the ST25R3916 to have all information necessary to generate automatic responses during anti-collision (UID for NFC-A and NFC-F, SAK, etc.).

Data transfer is done through a FIFO of 512 bytes. In a typical T4T use case the frames are limited to 256 bytes but the reader can and will issue multiple read-block commands on a T4T to retrieve much bigger data files. The firmware on the MCU just needs to provide the data requested to the FIFO. So it becomes a limitation of the MCU.

Regards, Ulysses