Can you use nfc T4T and T2T libraries in same application/build?

RE: Can you use nfc T4T and T2T libraries in same application/build?

Simonr — Fri, 11 Jun 2021 10:39:47 GMT

Hi again

When the NFC_tXt_setup() functions return error code 8 (INVALID_STATE) it means that the emulation already is in running state. This is related to a bug discovered in SDK v17, described here, where the nfc_t4t_done() call actually doesn't uninit the NFCT driver, and you need to call the nrfx_nfct_uninit() function after nfc_t4t_done() in order to be able to reinitialize the NFC peripheral.

Best regards,

Simon

RE: Can you use nfc T4T and T2T libraries in same application/build?

jp_is_my_name — Wed, 09 Jun 2021 16:06:12 GMT

I tried it.

There were no link errors or warnings. I'm using IAR tools. I didn't make any SDK17 t2t or t4t related source changes. I didn't see anything in nrfx_nfct.c that needed changing.

The bad news is that the NFC functionality only works once. In other words you can start t2t or t4t and they work normally, but once you stop nfc neither mode will restart.

This is true even if only one mode is ever used. Seems like the problem may be with _stop() and/or _done(), but it is odd that one mode doesn't still work if the other mode is never used.

@@@@@@ Case 1 only T4 mode from RESET @@@@@@

nfc_t4t_setup() OK

nfc_t4t_parameter_set() OK

nfc_t4t_emulation_start() OK

nfc_t4t_emulation_stop() OK

nfc_t4t_done() OK

=======================

//2nd attempted use

nfc_t4t_setup() FAILS code 8

@@@@@@ Case 2 only T2 mode from RESET @@@@@@

nfc_t2t_setup() OK

nfc_t2t_payload_set() OK

nfc_t2t_emulation_start() OK

nfc_t2t_emulation_stop() OK

nfc_t2t_done() OK

(also receive NFC_T2T_EVENT_STOPPED)

//2nd attempted use

nfc_t2t_setup() FAILS code 8

RE: Can you use nfc T4T and T2T libraries in same application/build?

jp_is_my_name — Mon, 07 Jun 2021 20:53:05 GMT

Thanks. I guess I'll try it and update the ticket with the results.

As far as I could tell from inspection the nrfx_nfct_init() isn't called from the src so it is probably called in the library nfc_t4/2t_emulation_start(), which if true is good.

RE: Can you use nfc T4T and T2T libraries in same application/build?

Simonr — Mon, 07 Jun 2021 13:15:34 GMT

I think these libraries use the same IRQHandler, so I'm guessing trying to add both into one project might cause some "multiple definitions" errors, but as other than that, I can't think of why it should be a problem to have T4T and T2T in the same project. Please note that you might have to make some changes to the existing code in order to ensure that they use different handlers. The handler seems to be located in nrfx_nfct.c and it calls a callback set in nrfx_nfct_init().

Best regards,

Simon