ST25 NFC/RFID tags and readers

Is there any way to get an antenna working in reader mode (chip 3911) when placed very close to a metal surface (around 2–3 mm)?I did some experiments with NFC in modern smartphones — their antennas sit right on top of the battery surface, and everything works fine there. But when I tried the same idea with the 3911 and 3916 evaluation kits, the antennas turned out to be pretty much ineffective.

Hello,I am running tha example code on RPi 5 on Ubuntu. Everything compiles fine but I get a Segmentation fault. I did configure the hwconfig.hI added some debug messages to the code:int main (void) { const ST25DV_PASSWD st25dv_i2c_password = {.MsbPasswd = 0, .LsbPasswd=0}; /* Init of the Type Tag 5 component (ST25DV-I2C) */ (BSP_NFCTAG_Init(0) != NFCTAG_OK); printf("ST25DV-I2C init done\r\n"); printf("DEBUG1\n"); /* Present configuration password */ BSP_NFCTAG_PresentI2CPassword(0, st25dv_i2c_password ); printf("DEBUG1.5\n"); /* Set GPO Configuration */ BSP_NFCTAG_ConfigIT(0,ST25DV_GPO_ENABLE_MASK | ST25DV_GPO_FIELDCHANGE_MASK ); printf("DEBUG2\n"); while(ST25DV_GPO_Init() != NFCTAG_OK); printf("GPO init done\r\n");This is where it crashes:./st25dv-i2c_gpo ST25DV-I2C init done DEBUG1 DEBUG1.5 Segmentation fault (core dumped) Any help will be appreciated. 

Hi everyone!I have just downloaded STSW-ST25002 source code and tried to build it in freshly installed Android Studio (Win11), but I got a couple of errors like "com.st.st25nfc.BuildConfig not found".Can someone give me exact steps to be able to build this application?The target goal is to remove all unnecessary parts except firmware update.Thanks!

Hi,I am working on a React Native project for an NFC app that needs to run on both iOS and Android. I am using the react-native-nfc-manager library to perform NFC operations. The NFC tag I am using is ST25DV, which supports NDEF and NfcV (ISO15693) technologies.Some basic functionalities the app would perform are reading and writing raw memory blocks to the memory.I noticed when I am using iOS device to perform read write operation, it can do so while keeping the tag intact with iOS device. I don't have to practically take the tag away from device and bring it near again to start the new nfc session.In case of Android, to perform the writing functionality, I have to first send the command from device by pressing button, then device will start looking for NFC tag. I bring the NFC tag near the device; it detects it and locks in the session and sends the command to the tag and closes the session. Thats how the code is written.Now if I want to read back from the tag, I press the read butto

I’m working on an iOS(17+ using Swift) app using CoreNFC and need to manage passwords on ST25 tags.The goal:Authenticate with the existing password (assuming I already have).Remove the password (disable protection).Immediately set a new password in the same NFC session.The issue:• The chip doesn’t actually clear the password.• Commands fail with “Tag connection lost”.It looks like I’m not reading/writing the configuration pages correctly or missing a required sequence.What I needA working Swift implementation that:• Authenticates with the existing password,• Removes/clears it,• Sets a new password,• All in one NFC session.Any code snippets or idea would be really helpful.

Hi,for a project we are evaluating we need to read bank/credit card data via NFC (Number, expire date, ccv/cvv) to record when people are accessing a gate and when are leaving; similar to the underground gateways that could be accessed with credit cards directly.Could we do it with any of the ST25 NFC readers (e.g. ST25R3916B)?As we do not have to process any payments could we get the credit card data simply using the reader functionalities or do we need any additional software components? (Beside the rfal middleware). Kind Regards,Andrea

Hi.I'm in progress of making an iOS app that needs to send custom commands to a ST25DV tag. I've been going through the same error all week (Feature not supported, from CoreNFC), so I started using the ST25SDKiOS but I still don't get how to use it. I was wondering if there is any instruction to use it to send custom commands to the tag.Thanks.

Hi everyone,I'm currently working with the ST25DV04K NFC tag connected to a Nucleo board, and I need to read and write text data to the tag for application development. I'm looking for:Example code to perform text read/write operations.A middleware library that supports text data access from memory blocks.Compatibility with STM32 MCUs for future integration.I've explored the examples provided in X-CUBE-NFC4, but most of them focus on writing url using NDEF_URL. Unfortunately, I couldn't find any examples or libraries that support reading/writing plain text to the tag. Also, the read NDEF_URL example throws error.My goal is to read data from this NFC tag connected to the Nucleo board or STM32mcu via I2C  .The data can be written by an NFC tap Application, which works fine with the ST25DV04K IC. Any guidance, sample code, or library recommendations would be greatly appreciated.Thanks in advance!

When we use 3920B to read the M1 card, the data sent to 3920B by MCU is "60 3C 1A 80", but compared with the data sent by 3920B captured by equipment, it is found that there are two more bytes "00 00" behind the data sent by 3920B. The difference is shown in the attached picture. Why does the data sent by 3920B have two more bytes? Will this extra byte affect the total length of bytes sent?Use the rfalNfcDataExchangeStart () function to send data, but only the interruption of sending data is completed, and there is no interruption of receiving data, so it has been circulating in do while. The card did not reply to the data sent by 3920B. Is this phenomenon related to the abnormality of the data sent by 3920B?

I am working on a React Native project for an NFC app that needs to run on both iOS and Android. I am using the react-native-nfc-manager library to perform NFC operations. The NFC tag I am using is ST25DV, which supports NDEF and NfcV (ISO15693) technologies.In my app, I need to perform:Writing different types of NDEF messages (URI, AAR, etc.).Writing directly to static registers (e.g., RFA1SS, ENDA1, RF_PWD_1, etc.).For writing to registers, I need to access raw memory blocks, which requires NfcV commands.According to the react-native-nfc-manager documentation, NfcV is not supported on iOS. That leaves me only with NDEF, as the tag only supports NDEF and NfcV.My questions:Is there any way to access or write to those registers on iOS without NfcV?Is there a workaround to enable or simulate NfcV support on iOS?Or am I limited to NDEF-only operations on iOS with this tag?Here’s a snippet from my current code that uses NfcV to write a static register (works on Android) I haven't tested th

Hi I would like to use the same pcb antenna used in the STVAL-SMARTAG2 board in our product. Could you provide some more information on the pcb (thickness, material, impedance, etc) in order to keep the antenna performance?    BR Gilberto  

hi all, I am planning to use a ST25R200 as non standard load shift keying receiver for medical applications. The use of the TAD1 en 2 pins could help monitoring the internals and optimize the filter and correlator settings. what are the registers to control these pins ?  

Hello. I am making a custom PCB with a custom antenna and ST25R on the board.Antenna: single-ended (RF0, RF1).Bundle: Nucleo-C031C6 with STM32 for communication via I2C with my PCB.The antenna has a SWR at a frequency of 13.56MHz is about 2.2 (not ideal, but for testing it should work). The spectrum analyzer shows that the field is established by command cmd = 0xC8 and with a fairly strong signal. It seems to me that my problem is somewhere in the configuration or the commands used.I will briefly describe the steps (the code is presented below):STEP 1: Reset to default state with a command 0xC0.STEP 2: Basic interface configurationWrite IO config1 (0x00) = 0x81 (Single antenna, sup3V, No LF clock)Write IO config2 (0x01) = 0xA6 (sup3V, AAT EN, I2C, VDD_RF)STEP 3: Automatic regulator adjustment wit ha command 0xD6.STEP 4: Enable regulators and oscillator Operation control (0x02) = 0x80 (bit EN = 1)Delay 100msSTEP 5: Configure operation mo

HiI am designing a small circular PCB with the following specifications. Due to size limitations, the antenna cannot exceed 9mm, which prevents me from achieving the recommended 4.8µH of inductance. Is it acceptable to compensate for this by increasing the matching capacitance?Additionally, I have two other questions:1. what is the recommended spacing for an NFC antenna from the edge of the PCB?2. Also, which formula do you use to calculate the inductance Circular or spiral () since I get two different results. Please let me know if you need additional information.Thank you  (mm)PCB Radios10.5N Turns3Space from Edge0.5Track Width0.28Spacing0.13First 9.86Second9.45Third9.04Spiral L0.35uHCircular L76nH  

Hi, I bought ST25RU3993-HPEV and In the tag authentication menu I want to use 29167-10 as CSI and there is a field with 'keyID' parameter. I want to know what is the key which this ID is assigned to. you know, the key in the tag and the the reader must be same for encryption and decryption. I want to know the 128-bit key used for this cryptographic suite indicator.And one more thing, according to the ISO/IEC 29167-10 standard, there are MAM and IAM functions, but in the GUI I can only select between TAM1 & 2. how can I use these features with this reader?Thanks.

Hi ST team , I have designed NFC reader using ST25R3916B  with single ended antenna connected with cable. Antenna is on different PCB. I would like to read ISO1443A tags using this antenna and want to have read range of around 5 cm. Right now when i am able to read the tags but with no range, i need to touch the tag on antenna. Pls help me to tune my matching circuit on reader side and on antenna side. I am attaching here reader schematic, antenna schematic , antenna PCB. Let me know what component value should i choose to get that range. Also I dont have VNA , so i am not able measure antenna parameters and not able to use ST antenna matching tool, so pls provide me the best component values to based on the schematicsReader sideAntenna sideAntenna PCB - 4 turns, 50mm x 50mm square, track width = 0.152mm,  track spacing  =  0.2mm RegardsDilip Motwani  

Hi, Every time I try to connect the eval kit to the GUI I get this error:This board doesn't reply properly to connect !Can anyone tell me how to solve this problem.  I have made sure that the correct COM Port and baud rate is selected. Also, the power indicator LED is ON and the RED LED is flashing. Your help is greatly appreciated.Regards,

Hello,I am currently trying to modify the schematic of the X-NUCLEO-NFC08A1 to support the connection of any commercial NFC antenna.From my understanding, I need to add a standard RF connector (SMA/U.FL/IPEX, etc.). Since commercial antennas are typically designed with a 50-ohm impedance, I believe the matching network may need to be redesigned as well. However, I am new to PCB and RF design, so I am not very experienced yet.I would greatly appreciate any guidance or advice on the basic steps to achieve this. If there are any relevant reference documents or application notes, I would be very thankful if you could share them.Thank you!

Hello,  I am working on implementing the CR95HF RFID reader into a project, and I'm having some trouble with the external crystal starting; I'm wondering if anyone has had a similar issue.  On my design I have the CR95HF connected to an NRF52840 MCU through UART. When I send the ECHO command (0x55) over the UART bus, I do not get any response from the chip. I have verified the following: The chip is properly receiving 3.3V at all of its power supply pins. The SSI_0 and SSI_1 pins are properly tied to ground to select UART communication Baudrate for UART is set to 57600, the default for this chip I pulse the UART_RX/IRQ_IN pin low for ~150us on startup to properly select the protocol On an oscilloscope, I can see that the XOUT pin that goes to the crystal rises to just above 0.5V on powerup, but the crystal never begins oscillation (see attached image). I am using the XRCGB27M120F3M00R0 from Murata, which is 27.12MHz with ~150 ohm ESR and 6pF load capacitance. I will pr

Hi everyone!I am currently testing the reading of a tag with an ST25TV02K chip using two different readers. Both readers are based on the same NFC chip and use the same antenna coil, but they differ in the matching network between the NFC chip and the antenna.In theory, the first reader should be better matched to the NFC chip, while the second reader should be less well matched (and therefore expected to deliver less power). I have verified the reader matching using a VNA. However, I am observing an issue: at the same tag-to-reader distance and with the same power settings, tag read/write operations with the ST25TV02K sometimes fail when using the better-matched reader. This makes me wonder whether the better-matched reader might actually be delivering too much power to the tag, such that the VAC0–VAC1 voltage exceeds the maximum limit, preventing the ST25TV02K from responding correctly. Conversely, the less well-matched reader could be delivering lower power, keeping VAC0–VAC1 w

Hello, I am using STEVAL 25R200 board to read/write NFC tags. Currently, I am using NFC V type tag which is getting detedted by the EVAL GUI software as well as by the code I implemented using RFAL layer functions through Cube IDE. My tag UID as seen in the EVAL GUI is e002080ab3e64bc8 which matches what I am getting after rfalNfcGetActiveDevice() function executes. I have the following testReadNfcBlock() function based on the rfalNfcvPollerReadSingleBlock() function. I am calling this function with input parameter as the dev->nfcid (that I get from the rfalNfcGetActiveDevice) inside the while loop. The read fails with a timeout error code 4. I even tried reversing the UID just to confirm that the UID handling error is not the problem.P.S. I checked out a similar post 'https://community.st.com/t5/st25-nfc-rfid-tags-and-readers/x-cube-nfc6-polling-demo-modification-and-sending-commands-to/m-p/635714#M10285' where a similar(same?) error is discussed but t

I am facing difficulties configuring the GPO interrupt on the ST25DV04KC to trigger exclusively when an NDEF message is written to the tag via the RF interface. The NDEF formatting is working correctly, and I am able to read and write data without issues both through the RF interface and via my microcontroller using the I2C protocol. However, I have not found a configuration or register setting that allows the GPO to generate an interrupt solely upon an NDEF write event initiated from the RF side.The interrupts are only working if I configure them as shown below.NFC07A1_NFCTAG_ConfigIT(NFC07A1_NFCTAG_INSTANCE, ST25DVXXKC_GPO1_ENABLE_MASK | ST25DVXXKC_GPO1_FIELDCHANGE_MASK);However, in this configuration, as expected, the interrupts are triggered simply by bringing the RF device close to the tag, without performing any read or write request. Therefore, this behavior does not serve the intended purpose.I tried the configurations below but was not successful. Shouldn’t this work?NFC07A1_N

Hello, I am using STEVAL25R200 evaluation board and integrating read/write application using the ndef_read/write examples provided in the documentation embedded library. In my main function, I am Initializing the NFC using rfalNfcInitialize(), rfalNfcDeactivate() and rfalNfcDiscover(). In the while loop, using the rfalWorker() function, I am polling for NFC tags. I have checkd using the EVAL GUI software that a NFC V tag in indeed present and being detected along with its ID (e002080ab3e64bc8).However, the tag is not detected in my code. I get the rfaNfcGetState = RFAL_NFC_STATE_POLL_TECHDETECT on my serial terminal and then it waits indefinitely. In my opinion, the activation of tag needs to happen using Interrupt routine but it never gets called and I never even proceed further. I have set my IRQ (PA0) and SS (PB0) pins in nfc_conf.h and initialized the IRQ pin as follows.#define BUS_SPI1_NSS_GPIO_PIN GPIO_PIN_0#define BUS_SPI1_NSS_GPIO_PORT GPIOB#define BUS_SPI1_

 Hello,I’m working with an ST NFC tag (e.g., ST25DV) and noticed that when I add an NDEF record using the ST25 mobile apps, the system automatically adds a 4-byte Capability Container (CC) to the NDEF message record.My question is:Is there a way to append or extend the CC to 8 bytes instead of the default 4 bytes when adding an NDEF record?  

Hello,I’m working with the ST25R3911 NFC reader IC in a battery-powered application where ultra-low power consumption is critical.Is it allowed to completely switch off VDD_IO while VDD is still supplied (e.g., when the device is in Wake-Up mode)?Will the interrupt pin still work in Wake-Up mode if VDD is present but VDD_IO is off?I noticed that even when VDD is off, if VDD_IO is connected, there seems to be additional leakage current. Could you clarify the expected current paths in such cases?Is there any recommended sequence for powering up/down VDD and VDD_IO to avoid unwanted currents or undefined states?Can VDD_IO be powered directly from a microcontroller GPIO pin (to save power by enabling it only when needed)? What is the typical consumption of VDD_IO in idle conditions?