nRF52 write NFC Tag

RE: nRF52 write NFC Tag

david.drinn — Tue, 24 Jul 2018 04:22:51 GMT

Thanks for this! How's it going in the past 2 years? Has it been working well? Thx again. :) Any chance a newer cleaned up version is available?

RE: nRF52 write NFC Tag

Eirik Midttun — Fri, 03 Feb 2017 12:35:57 GMT

Tag write and Tag Type 4 is now available. See the blog section.

RE: nRF52 write NFC Tag

thln — Mon, 14 Nov 2016 17:04:44 GMT

Hi, It's just the Device ID of my device. 0x5F, 0xF6, 0x4C, 0x6D, 0x2F, 0xF4, 0xDA, 0x59, 0x58 (with BCC).

You should replace it by your own device ID according to the : NRF_NFCT->NFCID1_LAST and NFCID1_2ND_LAST registers (for 7 bytes ID)

RE: nRF52 write NFC Tag

Alvaro_Val — Mon, 14 Nov 2016 08:39:38 GMT

Hi, I mean i dont understand these: 0x5F, 0xF6, 0x4C, 0x6D, // Internal 0-3 0x2F, 0xF4, 0xDA, 0x59, // Internal 4-7 , the other bytes from the static uint8_t Test_Memory_Type2 i do understand. Thanks

RE: nRF52 write NFC Tag

Alvaro_Val — Fri, 11 Nov 2016 13:35:14 GMT

Hi, I have been trying to find why do you use these Internal Bytes inside : static uint8_t Test_Memory_Type2[NFC_MAX_PAYLOAD_SIZE_RAW] = { 0x5F, 0xF6, 0x4C, 0x6D, // Internal 0-3 0x2F, 0xF4, 0xDA, 0x59, // Internal 4-7 I have study the protocol and i dont understand why do you use these bytes, and not others, if i use the ones that my nfc Tag makes it doesnt support the write commands, and the nfc doesnt work. Could you explain to me, why do you use these particular and no others with different values? Best regards

RE: nRF52 write NFC Tag

thln — Mon, 24 Oct 2016 07:22:34 GMT

Hi,

The sample code that I have published above is a simple way to have the write feature on nRF52. This code is not perfect, It's just first try ;) I've improve it and I' am writing the full nfc library to replace the Nordic one. For more informations to understand how it works, you can read the NFCForum Specifications.

NFCForum Digital Protocol found here : cwi.unik.no/.../NFC_forum_digital_protocol.pdf and NFCForum Type2Tag found here : apps4android.org/.../NFCForum-TS-Type-2-Tag_1.1.pdf

RE: nRF52 write NFC Tag

Alvaro_Val — Wed, 19 Oct 2016 14:03:08 GMT

Hi I have recently started developing with nordifc nrf52, andi have some doubts. Could you post the full program?. I have found several mistakes. With this code you are able to write via NFC in your nrf52? Thanks

RE: nRF52 write NFC Tag

thln — Mon, 19 Sep 2016 13:50:48 GMT

Hello,

The write NFC Tag is now enabled :)

I've removed the libnfc library because it didn't support the write feature, and no documentation is provided by Nordic to manage it. Furthermore the library gives information to the host (the NFC reader), that the card is NOT writable. So the host will never send the write request (0xA2).

What exactly does this library? It simulates a Type2 NFC buffer card, and provided data to the HAL driver. I've replaced it, by a function who sends the buffer content with the right datas.

static uint8_t Test_Memory_Type2[NFC_MAX_PAYLOAD_SIZE_RAW] = {
	// page 0
	0x5F, 0xF6, 0x4C, 0x6D,	// Internal 0-3
	0x2F, 0xF4, 0xDA, 0x59,	// Internal 4-7
	0x58, 0x03, 0x00, 0x00, // Internal 8-9 | Lock0-1       // <-- makes the card writable !
	0xE1, 0x11, 0x7C, 0x00, // CC0-3						// <-- makes the card writable !
	// page 4
	0x03, 0x16, 0xC1, 0x01,	// TLV Tag field, Length field, Value field
	0x00, 0x00, 0x00, 0x0F, // NDEF Payload length 15
	0x54, 0x02, 0x65, 0x6E, // NDEF Message Type : Text UTF8, "Hello World!"
	0x48, 0x65, 0x6C, 0x6C, //
	// page 8
	0x6F, 0x20, 0x57, 0x6F,
	0x72, 0x6C, 0x64, 0x21, //
	0x00, 0x00, 0x00, 0x00,
	0x00, 0x00, 0x00, 0x00,
};

I've linked directly the application calls to the HAL functions to check if it's working

ret_val = nfcSetup(nfc_callback, NULL);

replaced by ret_val = hal_nfc_setup(nfc_callback, NULL);

welcome_msg_encode(ndef_msg_buf, &len);
ret_val = nfcSetPayload( (char*)ndef_msg_buf, len);

no need because the buffer is already set with the right datas

ret_val = nfcStartEmulation();

replaced by ret_val = hal_nfc_start();

So the main function looks like this below :

int main(void) {
	NfcRetval ret_val;

	printf("nfc_1 start\n");

	uint32_t err_code = NRF_LOG_INIT();
	APP_ERROR_CHECK(err_code);

	/* Configure LED-pins as outputs */
	LEDS_CONFIGURE(BSP_LED_0_MASK);
	LEDS_OFF(BSP_LED_0_MASK);

	ret_val = hal_nfc_setup(nfc_callback, NULL); // <-- callback to to application 
	APP_ERROR_CHECK(ret_val);

	// Start sensing NFC field
	ret_val = hal_nfc_start();
	APP_ERROR_CHECK(ret_val);
	while(1)
	{
		if (!NFC_NEED_MCU_RUN_STATE())
		{
			__WFE();
		}
	}
return 0;
}

And I've added the read & write command inside the NFCT_IRQHandler !

...
if (NRF_NFCT->EVENTS_RXFRAMEEND && (NRF_NFCT->INTEN & NFCT_INTEN_RXFRAMEEND_Msk))
{
    /* Take into account only number of whole bytes */
    uint32_t rx_data_size = ((NRF_NFCT->RXD.AMOUNT & NFCT_RXD_AMOUNT_RXDATABYTES_Msk) >> NFCT_RXD_AMOUNT_RXDATABYTES_Pos);

    nrf_nfct_event_clear(&NRF_NFCT->EVENTS_RXFRAMEEND);

	if (rx_data_size>NFC_CRC_SIZE) {
		rx_data_size -= NFC_CRC_SIZE;

		LOG_HAL_NFC("[NFC_HAL]: rx %02X [%02X]\r\n", m_nfc_rx_buffer[0], m_nfc_rx_buffer[1]);

        switch (m_nfc_rx_buffer[0]) {

        case T2T_READ_CMD :		// 30h
        	{
				uint8_t BNo = m_nfc_rx_buffer[1];
				if (BNo<252) /* Max Block number */
					hal_nfc_send(&Test_Memory_Type2[BNo*4], 16);
				else 
					/* hal_nfc_send(&Dymamic_Memory_Aera[0], 16); */
					hal_send_ack_nack(0x0);	// NAck
        	}
        	break;



        case T2T_WRITE_CMD :	// A2h
        	{
				uint8_t BNo = m_nfc_rx_buffer[1];
				if (rx_data_size==6) {
					LOG_HAL_NFC("[NFC_HAL]: receive");
					uint8_t i, c;
					for (i=0;i<4;i++) {
						c = m_nfc_rx_buffer[2+i];
						Test_Memory_Type2[BNo*4 + i] = c;
						NRF_LOG_PRINTF(" %02X", c);
					}
					NRF_LOG_PRINTF("\n");

					hal_send_ack_nack(0xA);	// Ack for write command
				} else {
					hal_send_ack_nack(0x0);	// NAck for write command : should be 0, 1, 4 or 5
				}
        	}
        	break;

        case NFC_SLP_REQ_CMD :
        	LOG_HAL_NFC("[NFC_HAL]: SLP_REQ\r\n");
        	m_slp_req_received = true;

        default:
        	/* Not a READ Command, so wait for next frame reception */
        	NRF_NFCT->TASKS_ENABLERXDATA = 1;
        	break;

        }
	}
...

the HAL send functions are listed below:

/**
 * send data to the host (the reader) with CRC16 
 */
hal_nfc_retval hal_nfc_send(const uint8_t *data, size_t dataLength)
{
	if (dataLength == 0)
	{
		return HAL_NFC_RETVAL_INVALID_SIZE;
	}

	
	/* Ignore previous TX END events, SW takes care only for data frames which tranmission is triggered in this function */
	nrf_nfct_event_clear(&NRF_NFCT->EVENTS_TXFRAMEEND);

	NRF_NFCT->PACKETPTR     = (uint32_t)(data);
	NRF_NFCT->TXD.AMOUNT    = (dataLength << NFCT_TXD_AMOUNT_TXDATABYTES_Pos) & NFCT_TXD_AMOUNT_TXDATABYTES_Msk;

	uint32_t reg = 0;
	reg |= (NFCT_TXD_FRAMECONFIG_PARITY_Parity << NFCT_TXD_FRAMECONFIG_PARITY_Pos);
	reg |= (NFCT_TXD_FRAMECONFIG_DISCARDMODE_DiscardStart << NFCT_TXD_FRAMECONFIG_DISCARDMODE_Pos);
	reg |= (NFCT_TXD_FRAMECONFIG_SOF_SoF << NFCT_TXD_FRAMECONFIG_SOF_Pos);
	reg |= (NFCT_TXD_FRAMECONFIG_CRCMODETX_CRC16TX << NFCT_TXD_FRAMECONFIG_CRCMODETX_Pos);
	NRF_NFCT->TXD.FRAMECONFIG  = reg;

	NRF_NFCT->INTENSET      = (NFCT_INTENSET_TXFRAMEEND_Enabled << NFCT_INTENSET_TXFRAMEEND_Pos);
	NRF_NFCT->TASKS_STARTTX = 1;

	LOG_HAL_NFC("[NFC_HAL]: send");
	uint8_t i;
	for (i=0;i<dataLength;i++) {
		NRF_LOG_PRINTF(" %02X", *(data+i));
	}

	NRF_LOG_PRINTF("\n");


	return HAL_NFC_RETVAL_OK;
}

/**
 * send a ack or nack to the host (the reader) without CRC16
 */
static hal_nfc_retval hal_send_ack_nack(uint8_t ack_nack_code) {
	static uint8_t Ack;
	Ack = ack_nack_code;

	nrf_nfct_event_clear(&NRF_NFCT->EVENTS_TXFRAMEEND);

	NRF_NFCT->PACKETPTR     = (uint32_t)(&Ack);
	NRF_NFCT->TXD.AMOUNT    =  4;

	uint32_t reg = 0;
	/* reg |= (NFCT_TXD_FRAMECONFIG_PARITY_Parity << NFCT_TXD_FRAMECONFIG_PARITY_Pos); */
	reg |= (NFCT_TXD_FRAMECONFIG_SOF_SoF << NFCT_TXD_FRAMECONFIG_SOF_Pos);
	NRF_NFCT->TXD.FRAMECONFIG  = reg;
	NRF_NFCT->INTENSET      = (NFCT_INTENSET_TXFRAMEEND_Enabled << NFCT_INTENSET_TXFRAMEEND_Pos);
	NRF_NFCT->TASKS_STARTTX = 1;

	return HAL_NFC_RETVAL_OK;
}

Et voila !

RE: nRF52 write NFC Tag

Luke — Thu, 01 Sep 2016 14:00:13 GMT

Is there any news about tag writing? I would like to store some information on the nRF52 for binding porpuses.

RE: nRF52 write NFC Tag

Eirik Midttun — Wed, 04 May 2016 11:06:24 GMT

@CR: It is possible to write to the tag, what is missing is software support in the SDK. You have the possibility of writing the software yourself; see the nRF52 series product specification for hardware features, and the specifications for Tag Type 2 for the software. You can also implement Tag Type 4, but that will be more complex.

RE: nRF52 write NFC Tag

jfathman — Mon, 02 May 2016 20:26:19 GMT

Use case: I would like be able to write to the nRF52 via NFC to program the UUID, advertising interval, and transmit power level used by the Bluetooth beacon. Is there any new information whether writing to the nRF52 via NFC will be supported?

RE: nRF52 write NFC Tag

CR — Thu, 28 Apr 2016 15:10:08 GMT

For my use case I do need the tag to be writable. Any pointers where to start to get it work?

RE: nRF52 write NFC Tag

Alex — Mon, 25 Jan 2016 15:27:54 GMT

No problem. I modified my use case, write is not necessary any more :-) (Originally I wanted to pass a kind of ID to an IoT device via NFC.)

RE: nRF52 write NFC Tag

Eirik Midttun — Mon, 25 Jan 2016 11:30:18 GMT

Unfortunately I cannot comment on what will be included in future releases. Are you willing to share some information about your use case? There might be other solutions.

RE: nRF52 write NFC Tag

Alex — Mon, 25 Jan 2016 08:28:34 GMT

Erik, thanks for your fast reply. OK, it would be easier for me (my use case) if write is supported but I think I can also do it with read. Do you already know when write is supported by the SDK? Within weeks or rather months?

RE: nRF52 write NFC Tag

Eirik Midttun — Fri, 22 Jan 2016 16:16:04 GMT

nRF52 lets you implement an NFC tag which is a passive device and, as you say, cannot generate a field. A device (or poller, typically a phone or payment terminal) can read and write to a tag.

The library in the SDK is read only (at the moment), so you what you can do is to define the data in your application and a polling device can read it. The nRF52 is capable of supporting write, and it is possible to implement it. However, read only supports the majority of the use cases and avoiding writes save quite a bit of the flash memory.