ST25 NFC/RFID tags and readers

  Currently, we are developing a card reader featuring a circular NFC antenna. However, due to the lack of equipment for measuring antenna parameters, we are reliant solely on calculated theoretical values. The circuit board and antenna are depicted in Figure 1, impedance matching is shown in Figure 2, and simulation diagrams are presented in Figures 3 and 4. Is there any means to optimise the antenna design or draw the antenna? Alternatively, are any circular antennas readily available? The circular antenna requires a minimum diameter of 42mm and a maximum diameter of 50mm.   *This post has been translated from Chinese to comply with the ST Community guidelines.

We’re facing an issue with the ST25DV04KC tag. The tag is powered through energy harvesting. The GPO register unexpectedly resets to 00 whenever there’s a brief drop or interruption in the RF field or Communication. The GPO is configured to generate an interrupt when the tag enters an RF field, this interrupt is what signals the host device (via I²C) to initiate communication. When the GPO register resets, no interrupt is generated, so the host device can’t detect the RF field and communication never starts.As far as we know, the GPO register is a static register and should retain its configuration. Even after locking the configuration registers, the reset still occurs.Could you confirm if this is expected behavior, or if there’s a known workaround to maintain GPO configuration across short RF power losses or Communication drops?         

Dear ST Community,I hope you are doing great.I am having a trouble to run the GUI of ST25R3916 discovery board on my machine, I have windows 10 operating system, I tried to reinstall the included drivers (with the GUI), but the GUI is not able to recognize that the reader is connected to my PC. In the device manager when I connect the board I am getting the following drivers in my list:Universal Serial Bus Devices --> ST-link debugPorts (COM and LPT) --> STMicroelectronics STLink Virtual COM PortAlso I have used dfu-util to check if my system can identify the DFU, but It can not. I tried different PCs, but all have windows 10 OS. I am getting the same problem in all of them.I would really appreciate your help. Thank you very much.

Hi. I recently started using set "NUCLEO-L476RG" and "NUCLEO-NFC08A1"..I launched the existing "NFC08A1_PollingTagDetect" project, which works via SPI, and everything worked fine.Then I decided to redesign the project for I2C. I ran into some problems and questions.Questions:1) According to the "X-CUBE-NFC6" manual for implementing I2C:3.5.1:• solder ST2 and ST4 jumpers.• solder R116 and R117 pull-up resistors.• remove the SPI solder bridge.• install the I²C solder bridge.However, according to 6.2 of the same manual:it is also necessary to "Connect jumper wires from ST2 to ST5 and ST3 to ST6."Question: So, which step should I follow? Do I need to connect ST2 to ST5 and ST3 to ST6?2) If I still need to connect ST2 to ST5 and ST3 to ST6, then ST3 is missing in the "NUCLEO-NFC08A1". What should I connect instead?Problems:What I did:Hardware:• solder ST2 and ST4 jumpers.• solder R116 and R117 pull-up resistors.• remove the SPI solder bridge.• install the I²C solder bridge.• solder ST2 to S

Hello to the support community,  i'm currently working on some custom coils used with the ST25R3916. I've studied the ISO/IEC 14443-2 for quite a while and recently had a look into the AppNote AN6065 from you guys.  There is quite some confusion on the topic stated in the AN around Figure 15.First of: the minimum timing values stated in Table 3 are somewhat different from the ones in the actual ISO norm. That is not really the point of my question, but i just wanted you to know.  The real question arises from the following fact:In the AN the Q factor of the coil is calcaulated to be Q<= 13.56 MHz * 3µs = 41. (The very bottom line on Page 18).The 3µs represents the time that the unloaded coil would need to rise/ fall to the min/max amplitiude. So far so good.  Looking at this timing diagram: I would expect that those 3µs would represent t3 or t1-t2 as those are the rise and fall times of the symbol. Looking in the table:* t3 = 16/fc =

Hi. I bought a set of "NUCLEO-L476RG" and "NUCLEO-NFC08A1".The "X-CUBE-NFC6" library for the "NUCLEO-L476RG" contains examples of "NFC08A1_PollingTagDetect" and "NFC08A1_PollingTagDetectNDEF."How do I run them in the STM32 IDE?Which one should I use to read the tags and output data via UART?Please, could you help with that? I'm a beginner with NFC and all my attempts to run it - failed.The instructions included with the library are uninformative.

Hi,I am using this library on Rpi5:https://www.st.com/en/embedded-software/stsw-st25r021.html#overviewI modified the gpio_init thuslystError gpio_init(void) { int ret = 0; char gpiochip_file[SIZE]; if (isGPIOInit) { return ERR_NONE; } sprintf(gpiochip_file, "/dev/gpiochip4"); /* Open /dev/gpiochip0 */ int fd = open(gpiochip_file, O_RDONLY);I modified the rfal_platform.h to correspond to my interrupt pin/* Set the GPIO pin number used as interrupt line to receive interrupts from ST25R */ #define ST25R_INT_PIN 12 /*!< GPIO pin used for ST25R External Interrupt */ #define ST25R_INT_PORT (fd_GPIOs[0]) /*!< But the demoIni function fails (I added some debug statements) bool ok = demoIni(); printf("debug1, demoIni result %d\n", ok); while ((!ok) || (ok && i--)) { platformLedOn(PLATFORM_LED_FIELD_PORT, PLATFORM_LED_FIELD_PIN); platformLedOn(PLATFORM_LED_A_PORT, PLATFORM_LED_A_PIN); platformLedOn(PLATFORM_LED_B_PORT, PLATFORM_LED_B_PIN); platformLedOn(PLATFORM_LED

Hi everyone,I'm working on a project where I need to read NFC tags from 4 different locations. To save costs and complexity, I'm considering using a single ST25R3916B and multiplexing it to 4 antennas.From what I've found, it's possible to use the differential matching network as two single-ended matching networks, which would give me 2 antennas. By adding a 1:2 multiplexer on both TX/RX lines, I could get up to 4 antennas. Alternatively, I could use a single-ended configuration with a 1:4 multiplexer.From the ST community, I saw that some people used relays, but I'd like to avoid them due to the audible switching and bulky size. RF switches and transistor-based multiplexing have also been mentioned, but I couldn’t find much concrete information about how to implement them or which components to use.So here are my questions:Has anyone successfully implemented a multiplexer using transistors? If so, how?Has anyone implemented RF switches for this purpose? What was your approach?Which an

Hi everyone,I am working with the X-NUCLEO-NFC08A1, which uses the ST25R3916B chip, and I am planning to use it's main IC (ST25R3916B ) with 6 antennas. The idea is to use the two RF interfaces of the chip, with each interface connected to 3 antennas.I would like to know if anyone has experience or recommendations on how to handle antenna multiplexing for this setup. Specifically, I’m wondering whether it would be better to implement the multiplexing using PIN diode circuits or if it would be more suitable to use an RF switch. Are there any other solutions or approaches that should be considered? Do you have any specific IC (related) recommendations?Additionally, I’d appreciate some insights on where the multiplexing circuitry should be located. Should it be positioned between the IC and the antenna circuit (IC-xx-AntennaCircuit-Antenna) or between the antenna circuit and the antennas themselves (IC-AntennaCircuit-xx-Antenna)?Looking forward to your advice!Best regards,

Hi everyone,I'm working on a project that requires multiplexing 6 NFC antennas to a single NFC reader, such as the ST25R3916B. From my understanding, because the reader uses separate RFOx (TX) and RFIx (RX) lines for differential communication, I need to multiplex both RFOx and RFIx for each antenna.The most cost-efficient and compact approach I can currently think of looks like this:STM32 + ST25R3916B (RFOx/RFIx)--> Matching Network--> RF MUX--> [optional EMC Filter]--> AntennaAlternatively, if I place the matching network after the multiplexer like this:STM32 + ST25R3916B (RFOx/RFIx)--> RF MUX--> Matching Network--> [optional EMC Filter]--> Antenna…then I would need two separate MUXes per antenna path (one for RFO, one for RFI), effectively doubling the number of switches, which significantly increases both cost and board space. My questions:Has anyone implemented method 1 (matching network before the MUX)?Are there known issues (e.g., detuning, crosstalk

I was trying to setup the software (ST25R010) for NFC reader, and not only was I unable to setup the software but I realized the board malfunctioned at some point. The board initially worked fine but now it shows a reversed error message and I cannot reset the board. In terms of setting up the software, I was trying to update the firmware as instructed in 1.3 of the user manual. I am using windows 11 laptop with x64 architecture. I tried following Method 1 at user manual 1.3.1 but I could not find the STM32 Bootloader, so I moved on to method 2. I downloaded and installed ST Link Driver from https://www.st.com/en/development-tools/stsw-link009.html and moved the firmware file to MB1396 (the board I connected to my laptop using usb). I think this might have caused the board to show error screen but I'm not sure. Can I please get some help with 1. resetting the board/removing the error in the board, 2. Setting up the GUI software on my laptop?

For our NFC project, we are developing a mobile application that supports both iOS and Android. We are using React Native along with the react-native-nfc-manager library. Some of the core features include reading and writing raw memory blocks as well as handling different types of NDEF messages.At the moment, I am working with third-party NFC modules that come preloaded with an NDEF message and a CC file, and that support both NfcV and Ndef technologies. Reading and writing raw data with these modules is straightforward using NfcV transceive on Android and ISO15693Ios sessions on iOS. NDEF messages can also be read and written directly by opening an Ndef technology session.However, these modules don’t represent factory-fresh tags. To simulate a new tag with empty memory, I clear the tag’s memory using the ST NFC mobile application, which wipes both the CC file and any NDEF messages.After clearing, the tag only supports NdefFormatable technology. I am unable to format an empty tag back

Hello everyone. I'm currently developing and testing an embedded C software for microcontroller STM32L476 integrated on board ST25R3911B.In order to better understand FTM and its features, I'm trying to use a ST25NFC_Embedded_Lib_ST25R3911B_1.8.0 demo project ( \ST25NFC_Embedded_Lib_ST25R3911B_1.8.0\Projects\STM32L476RG-Nucleo\Applications\X-NUCLEO-NFC05A1 ).Currently I'm facing RX issues on packets over 32 bytes.Down below I attach thw two log outputs (TX = 32 bytes, RX = 32 bytes) and (TX = 96 bytes;  expected RX = 192 bytes)I really don't understand what's messing around here since everything on my traget device is actually working fine.Thank you.

Hi all，I now use ST25R3920B as a card reader on the official nucleo nfc08A1 of ST to read cards. However, I found that when the card was detected by 3920B, the current increased to 300mA, but the maximum current borne by PCB was 350mA.Can I reduce the current and how should I operate the configuration software code? 

I use the Flutter NFC Kit library.I enter the password and then use: Extended Read Multiple Blocks"2033XXXXXXXXXXXXXXX00003F00"Request_flags -> 20Extended Read Multiple Block -> 33UID -> XXXXXXXXXXXXXXXFirst block number -> 0000Number of blocks -> 3F00 == decimal 63 blocks (total read 64 blocks)With this line of code, I read 64 blocks, but if I try to read a larger number of blocks, for example, 128 blocks, passing 80h for Number of blocks, I receive an error message and the blocks are not read.Is it possible to read more than 64 blocks with smartphones?

Updated the title to be inline with ST community rules. Hi all! So I am looking for a standard antenna which would be suitable for ST25R100-CMET (IC Reader 13.56MHZ 24 UFQFN). This will be used in an alarm module with a lock, so please suggest! Thank you!

Dear Sir,  ST25R3911B-AQFT, we have noticed that the QFN32 package is different for COO=KR and COO=TH parts, referring to photos attached, is this normal? Is there any updated datasheet or PCN information to reflect such change?  The package of ST25R3911B-AQFT should have chamfers at its 4 corners and we have observed that COO=KR parts have 4 corners while COO=TH parts don't have it.     

I'm using ST25dv64KC memory and need to use Fast Extended Read Multiple Blocks C5h, but I haven't had any success.I'm passing the sequence "22C502E00251678F057ABB000001F00"22 - request flagsC5 - Fast Extended Read Multiple Blocks02 - IC mfg codeXXXXXXXXXXXXXXX - my UID0000 - starting block1F00 - ending block

Dear NFC Forum Community, we have recently developed a circuit design using one of STMicro’s latest NFC chips (e.g. ST25R200 as their most recent reader IC). We are very interested in having this design validated under NFC Forum conformance testing. We are based in Germany and have learned that IB-Lenhardt AG / IBL-Lab GmbH operates in St. Ingbert and is now officially designated as an Authorized Test Lab (ATL) for NFC Forum analog and digital conformance tests. The lab is ISO/IEC 17025 (DAkkS) accredited and works with validated test systems and robotics from COMPRION.https://ib-lenhardt.com/product-testing/nfc Do any forum members have experience working with IBL-Lab GmbH / IB-Lenhardt AG for NFC Forum conformance testing? If so:• What were the results and your overall impression of their services?• With what ballpark costs did you come across for an initial protocol / conformance test? Thank you in advance for any insights or contact suggestions. Best regard

The last few lines of  StMicro’s ST25DV-I2C  low power application note (high lighted) are ambiguous. Does “ST25DV-I2C” have the ability to read/write EEPROM without power applied between pins VDCG and GND? (YES/NO)  Our desired application needs to read/write EEPROM via RFID when microcontroller's battery is dead.   StMicro Literature (see attached *.pdf)Ultra-low power stateTo save power, the ST25DV-I2C is completely shut down most of the time. In that state, the GPIO connected toST25DV-I2C’s VCC pin can be either forced to low-level output, in high impedance mode. The GPIO connected tothe ST25DV-I2C’s LPD pin can be in any state, high or low output, or high impedance without any influence onpower consumption.If the ST25DV-I2C is powered by the RF field, it can receive and answer from any RF command and can sendan interrupt signal on its GPO pin to the microcontroller. The VDCG pin needs to be permanently powered. I2Ccommunication is not working. In

Hello We are preparing the following modes for the authentication test. 1) Unmodulated signal continuous output (typo corrected!) 2) Modulated signal continuous output 3) Adjust each signal output dB   1 and 3 have been resolved, and we are having difficulty outputting 2 modulation signals. So far, RFAL functions cannot output modulated signals continuously, and the driver code for ST25R3916 must be configured, but it has not been successful yet. (1, 3 are implemented as RFAL functions)The way I want to use it is "Start function call -> modulated signal continuous output" and "Stop function call -> output end". What I've tried now is that I've been working with rfalNfcWorker()  For "RFAL_NFC_STATE_POLL_TECHHDETECT", we fixed "gNfcDev.state" to "RFAL_NFC_STATE_LISTEN_TECHHDETECT" instead of "RFAL_NFC_STATE_STATE_DISCOVERY". Is this the right way?  

Hello,I recently added ST25R3916B to a board.  I followed the evaluation board schematic pretty closely.  During board "bring up" phase I had an issue where the osc_ok bit in `Auxiliary display register` was stuck low.  Specifically, after powering up the oscillator en bit in Operation Control Register..  The bit `osc_ok` bit always remained low. I spent some time trying to debug this from firmware perspective thinking that it may have been a firmware related issue [like incorrect sequencing]..  I ended up visually comparing the layout on my board to the STEVAL-ST25R3916B layout. In the STEVAL-ST25R3916B schematic the "HSE" xtal [Y200] shows 2x 10 pF loading capacitors [C217, C218] connected [see snip from STEVAL-ST25R3916B pg. 20].The bill of materials also lists Y200 + loading capacitors to be installed.  While visually inspecting the board... I noticed that [...what I believe to be...] the loading capacitors [C217, C21

Hello,I'm using RFAL with the ST25R3916 to emulate NDEF tags.The tag emulation works perfectly.Now, I'd like to get the RSSI when the emulated tag is read.My problem is that rfalGetTransceiveRSSI() and even the low evel st25r3916GetRSSI() always return 0, wherever I use them (after device is activated, after or before data exchange, ...).These functions return a correct RSSI value when the ST25R3916 is used as a reader; but not when it's used as a tag emulator.Any idea how I can get the RSSI when the emulated tag is read ?Thanks !

Hello,I’m working with an ST25R3916 and an ESP32-S3. I ported the RFAL library to the ESP32 (platform.c), and it works — I can successfully read a tag with this setup.However, I’m struggling to emulate a tag in order to send an NDEF message.Does anyone know where I could find an example implementation for this?For more context: when I enable tag emulation, my reader correctly detects the programmed UID, but I can’t manage to retrieve the NDEF.Thanks in advance.

 Hello everyone!This is my first time trying to use the ST25R chip. After struggling with the datasheet, I was referred to the RFAL library and the UM2890 manual.However, I couldn't find clear step-by-step instructions.:backhand_index_pointing_right: Therefore, I'd like to ask questions about the integration process in this thread.Perhaps this will also be useful to someone else in the future.Now I have issues with steps 4 and 5. Maybe someone could give me some advice on this?My setup:MCU: STM32C031C6 (NUCLEO-C031C6).NFC: ST25R3916B on a custom PCB via I2C.Notes:VDD_RF and VDD_DR connected together. 100nF to GND.VDD_AM has 2.2uF to GND.VDD_A and VDD_D have their own 10nF to GND.AAT_A and AAT_B are not connected.EXT_LM is not connected.TAD1, TAD2 are not connected.I2C_EN to VDD_D.Antenna: single-ended, onboard, connected directly to RF0 and RF1. Step 1 – ConnectionsUM2890 - 4.1:Pin definitions• ST25R_SS_PIN / ST25R_SS_PORT - Not used because I have I2C.• ST25R_INT_P