2.1 Documentation (API, Protocols, Manuals)
uFR Zero Online – Unified Firmware Package System
Last Updated: September 9, 2025µFR Zero Online – Unified Firmware Package System Introduction With the release of ESP32 firmware version 3.0.82, µFR Zero Online devices have adopted a unified firmware package system. This change simplifies firmware management by allowing developers to update both the ESP32 main controller and the NFC reader-writer in a single process. Instead of handling separate firmware updates, you now select from precompiled firmware packages that ensure both components always run mutually compatible versions. This article explains how the new system works, what package types are available, and how to resolve common issues when working with firmware packages. How Firmware Packages Work When you click “Check for Updates” in the device frontend: Individual firmware versions are no longer listed. Instead, you will see packages named in the format: Zero_Online_YYYYMMDD The date indicates when the package was created. A newer date corresponds to a newer firmware version. Once selected, the package automatically installs the correct versions of: The ESP32 main unit firmware The NFC reader firmware This ensures both parts of the device run on compatible builds. Package Variants Three types of firmware packages are available: Zero_Online_YYYYMMDD – the standard package for most devices. Zero_Online_Lite_YYYYMMDD – for Lite variants of µFR Zero...
Premium Firmware Upgrade Instruction – License Token Implementation
Last Updated: September 9, 2025uFR API References
Last Updated: July 5, 2024uFR API References – uFCoder Library Click to open the API webpage.
NDEF Message vCard property types – Virtual Contact File NDEF record writing
Last Updated: May 4, 2023NDEF Message vCard property types Virtual Contact File NDEF record writing Name Property presence Description Example v. 2.1 v. 3.0 v. 4.0 ADR Optional Optional Optional A structured representation of the physical delivery address for the vCard object. ADR;TYPE=home:;;123 Main St.;Springfield;IL;12345;USA AGENT Optional Optional Undefined Information about another person who will act on behalf of the vCard object. Typically this would be an area administrator, assistant, or secretary for the individual. Can be either a URL or an embedded vCard. AGENT:http://mi6.gov.uk/007 ANNIVERSARY Undefined Undefined Optional Defines the person’s anniversary. ANNIVERSARY:19901021 BDAY Optional Optional Optional Date of birth of the individual associated with the vCard. BDAY:19700310 BEGIN Required Required Required All vCards must start with this property. BEGIN:VCARD CALADRURI Undefined Undefined Optional A URL to use for sending a scheduling request to the person’s calendar. CALADRURI:http://example.com/calendar/jdoe CALURI Undefined Undefined Optional A URL to the person’s calendar. CALURI:http://example.com/calendar/jsmith CATEGORIES Optional Optional Optional A list of “tags” that can be used to describe the object represented by this vCard. CATEGORIES:swimmer,biker CLASS Undefined Optional Undefined Describes the sensitivity of the information in the vCard. CLASS:public CLIENTPIDMAP Undefined Undefined Optional Used for synchronizing different revisions of the same vCard. CLIENTPIDMAP:1;urn:uuid:3df403f4-5924-4bb7-b077-3c711d9eb34b EMAIL Optional Optional Optional The address for...
A corrupted µFR Nano Online firmware recovery – desktop app
Last Updated: October 10, 2023A corrupted µFR Nano Online firmware recovery – desktop app If you are experiencing a problem with a corrupted firmware of your µFR Nano Online device, and it cannot be connected to your network, or for some other reason you cannot access its web backend configuration in your browser, you need to recover the device using the desktop tools. Windows desktop tools – µFR Nano Online firmware recovery Plug the device into your Windows machine USB port and make sure your FTDI drivers are running properly. As you are probably already aware, the µFR Nano Online device consists of the two joined hardware, uFR Nano and ESP32, both having individual firmware. Therefore, one firmware flashing tool may not recover the entire device. It is most likely that the device’s ESP32 firmware failed. The console flasher can flash the uFR Nano reader of the device, but you first need to fix the ESP32 with the following ufr_online-flasher-oneclick tool (explained at https://www.d-logic.com/nfc-rfid-reader-sdk/software/ufr-online-flasher/). In case you have trouble detecting the device on the Windows machine, make sure you meet the following conditions: – FTDI drivers present – The device is plugged directly into the host machine USB port (not into the external power...
A corrupted µFR Nano Online firmware diagnostic and recovery – web backend
Last Updated: October 10, 2023A corrupted µFR Nano Online firmware diagnostic and recovery – web backend – µFR Reader Firmware Issue – This device has two pairs of LEDs. The top LEDs are connected to the ESP32 board and show the network connection status, while the bottom pair of LEDs are connected to the NFC reader. The bottom LEDs should flash green (slowly when there is no card near, and fast when you read the card). If you see any red light at the bottom or no light at all, then the µFR reader firmware is missing or corrupted. If you still can access your device’s web backend, please log in and check the device info as shown below: The red-marked fields contain the NFC reader firmware details. If you have no firmware data listed here, or if both, the reader serial and the firmware version are missing, the firmware of your device is corrupted. In this case, you can try resting the device on the factory settings. Then connect the device to your network again and flash both firmware again. Whatever firmware version your device has, it is recommended to upgrade to the latest release. This should recover all the device functionality....
How to flash-update µFR Nano Online Firmware
Last Updated: October 10, 2023µFR Nano Online Firmware flashing – upgrade & downgrade If you need to upgrade or downgrade your µFR Nano Online device, for the device connected to the desktop host (USB-connected) you may use the software tools provided for the µFR Online devices, or you can use the firmware update options of the device web configuration panel. For the desktop, you should download the following firmware flashing software – ufr_online-flasher-oneclick. This software tool implementation is further explained at https://www.d-logic.com/nfc-rfid-reader-sdk/software/ufr-online-flasher/. However, this device is designed to be used primarily as a network device so that it can be entirely configured and both its firmware (uFR and ESP32) can be updated using its online fronted options. To access its front-end panel, you need to connect the reader to your network. Then open its assigned IP address in your browser. Further, follow the steps of the demonstration video. 🔗 https://www.youtube.com/watch?v=5khSfhTnxV0&ab_channel=D-LogicNFC_SDK Please remember that the default login credentials for the device online configuration panel are: user: ufr password: ufr Both of the mentioned solution, desktop, and network, includes the Factory Reset option. However, be aware that the factory reset turns all the devices’ configuration options to their default values, but does not affect the firmware...
How to enable µFR Nano Online Log and Access Control Mode?
Last Updated: October 10, 2023µFR Nano Online Log and Access Control Mode How to enable log mode? Log in to the µFR Online Log and Access Control Module Online WEB configurator GUI. Enable Master mode if it is not already enabled. Click the Save and Restart option to apply the changes. Enable log mode (only visible after the Master mode is enabled) How to enable access control mode? Log in to the µFR Online Log and Access Control Module Online WEB configurator GUI. Enable Log mode. Enable Access Control mode (only available if log mode is previously enabled). Turn off µFR Online from the power supply Connect the Access control board. Turn on µFR Online from the power supply ***Access control mode has to be enabled before the access control board is connected. Access control mode additional options Relay pulse time: How many milliseconds relay outputs square wave pulse Relay pulse frequency: Square wave output frequency in Hz Relay pulse power: Square wave output power (duty cycle) Relay active time: How many milliseconds to stay output high after a square wave pulse Use cases This section will describes two primary use case scenarios. Log mode without access control Enable log mode and ensure...
How to enable BLE HID mode and pair the uFR Nano Online Reader with a smartphone?
Last Updated: October 10, 2023BLE Mode – Pairing & Connecting the uFR Nano Online Reader
Last Updated: November 3, 2022How to enable BLE mode on the uFR Nano Online Reader? Log in to the uFR Online WEB frontend settings page; Select Other Settings from the menu; If the reader is in Master Mode, change it to Slave Mode; Go to the BLE section (image below); To enable BLE mode, click the section button; The BLE security section will be displayed (image below); Navigate down for more information regarding BLE security modes; Click the Save and Restart button; After restarting the reader, the light blue light will blink. Notes: Blinking light blue LEDs indicate that the reader is waiting for a smartphone or other BLE-capable device to establish a connection. The device can be seen as a WiFi access point as well. A constant light blue LED shows that the reader is already paired. On BLE scanning, connected devices are not detected. The device is not visible acting as a WiFi access point. BLE security modes There are three BLE security modes. Details about all three are shown in table 1. Disabled security means that there is no open security channel and MITM protection. * Security disabled Security enabled and the PIN is set to 0 Security enabled and...
NDEF Detection and Access – MIFARE Classic & MIFARE Plus tags
Last Updated: November 21, 2022MIFARE Classic and MIFARE Plus IC memory NDEF data mapping methods
Last Updated: March 30, 2023iOS support for µFR Series hardware
Last Updated: October 10, 2023For iOS, we provide the µFR Series hardware library for iOS, the APIs, and other documentation related to hardware, as well as all the necessary technical support for your project development. As for the development tools and executable software solutions, the current iOS compliant SDK is available at our GitLab repository and the two apps at App Store. The SDK is compliant with all the µFR Series devices, while one of two available iOS apps is developed for the µFR Nano Online reader exclusively.
µFR Nano Online reader features – brief overview
Last Updated: October 10, 2023µFR Nano Online is a great choice for a standalone device. Its “Master mode” allows you to send all NFC tag read data to a predefined server. The HTTP POST request method is used for the data sending. The user can choose to send cards/tags serial numbers only or to send all the tag content. Features Basic µFR Nano Online information µFR Nano Online is an NFC Reader with WiFi and BLE connectivity. Optionally, Ethernet connectivity is also available through an adapter board. µFR Nano Online has configurable GPIO (4 pins) and UART for connecting additional NFC Reader. The device also features external EEPROM and optional RTC (Real Time Clock). Link: https://www.d-logic.com/nfc-rfid-reader-sdk/wireless-nfc-reader-ufr-nano-online/ Device composition and compatibility Nano Online is comprised of two main boards: 1. µFR Nano NFC Reader 2. ESP32 add-on board Because this device integrates µFR Nano, it enjoys SDK and features our other µFR Series devices do. This includes: – SDK in multiple programming languages – Cross-platform libraries – NFC tag emulation – Digital Signing support – Working with MIFARE cards (Classic, Ultralight, Ultralight C, DESFire, DESFire Lite, Plus), NTAG2xx, NTAG DNA, JCOP (Java Cards)… – Ever upgrading firmware, library, and software SDK support – Browser extensions (Chrome,...
FTDI drivers installation on 64-bit macOS
Last Updated: November 25, 2022FTDI drivers installation on 64-bit macOS Driver Installation Manual Download and unpack the drivers for your OS from the FTDI
FTDI driver installation and uFR SDK/software launching on Windows
Last Updated: October 10, 2023FTDI driver installation and uFR SDK/software launching on Windows step-by-step guidance - uFR series of the Digital Logic NFC RFID Reader Writer Development