Understanding Firmware Feature Variants in µFR Zero Series Readers #

Overview #

The µFR Zero series NFC RFID readers are designed to support a wide range of card types and advanced features. However, due to firmware memory limitations, not all features can be included in a single firmware release. For this reason, different firmware versions are published with slightly different feature sets.

This article explains why some features may appear to be missing on your device, and how to resolve issues by selecting the right firmware version for your project.

Common Developer Issues #

When working with µFR Zero devices, developers sometimes encounter issues such as:

• Attempting to use MIFARE Plus cards, but the device does not respond or authenticate.
• Attempting to use card emulation (HCE), but the reader does not recognize emulated cards.
• Unexpected differences between two devices running different firmware versions.

These situations are usually caused by firmware feature exclusions rather than hardware limitations.

Why Features Are Excluded #

Each µFR Zero firmware version has a fixed memory budget. Some advanced features—such as MIFARE Plus support or card emulation (HCE)—consume significant memory. To introduce new improvements or additional standards, the development team must occasionally exclude certain features to free up space.

The most common trade-off is:

• Versions that include MIFARE Plus usually exclude HCE.
• Versions that include HCE usually exclude MIFARE Plus.

Other features may also be temporarily excluded depending on ongoing development priorities.

How to Resolve Compatibility Issues #

If your project requires a feature that is not available in your current firmware, you can:

1. Check the firmware version currently installed on your µFR Zero device.

2. Review the changelog for that version to see which features are included or excluded.

3. If needed, upgrade or downgrade to another firmware version using the uFR Flashing tool.

   • Firmware versions are interchangeable across µFR Zero devices.

   • Choose the version that matches your project requirements (e.g., MIFARE Plus vs. HCE).

Important: Always use the official uFR Flashing tool provided by Digital Logic to update or change firmware.

Best Practices #

• Before starting development, identify whether your project requires MIFARE Plus, card emulation (HCE), or another specific feature.
• Select the firmware version accordingly.
• If you are unsure which firmware is best, contact our Technical Support team for guidance.

Troubleshooting #

If you encounter issues with missing functionality, follow this checklist:

Problem: MIFARE Plus cards are not working

• Verify your firmware version.
• Check the changelog: if MIFARE Plus support is excluded, you need to install a firmware version that includes it (e.g., version 10.0.53).
• Flash your device with the correct firmware using the uFR Flashing tool.

Problem: Card emulation (HCE) does not work

• Verify your firmware version.
• Check the changelog: if HCE support is excluded, switch to a firmware version where HCE is included (e.g., version 10.0.54).
• Re-test after flashing the device.

Problem: The Device behaves differently from another µFR Zero with the same hardware

• Confirm that both devices are running the same firmware version.
• If not, align them by flashing to the same version.
• Compare included/excluded features in the changelog.

Problem: Unsure which firmware version to use

• Determine whether your project requires MIFARE Plus, card emulation, or another feature.
• Select the firmware version accordingly.
• Contact Technical Support if your project requires multiple features that cannot coexist in the same firmware.

Related Resources #

• µFR Series Firmware Changelog (link to your firmware download/changelog page)

• Using the uFR Flashing Tool (link to instructions or tool download)

• Contact Technical Support