When the Core Tap detects a fault, it displays an error code on the System tab under Active Errors and signals the group visually via the status LED. This guide covers every defined error code, what it means, and the steps to resolve it.
How to read the LED: A solid red LED means a Group 0 hardware fault. For all other errors, count the number of red blinks per cycle - that number is the group. See the Status LED Reference for the full pattern table.
These errors indicate a permanent hardware failure at the lowest level of the device. The unit cannot operate correctly and requires physical inspection or repair. Rebooting will not resolve them.
LED: Solid red
Severity: Critical - device cannot function
The I2C master bus failed to initialise at boot. The I2C bus connects the Core Tap to internal peripherals. If the bus itself fails, none of these peripherals are reachable.
- Short circuit or wiring fault on the SDA or SCL lines inside the enclosure
- Internal hardware damage (e.g. from a power surge)
- Firmware corruption causing the driver to fail to start (rare)
- Power cycle the device. If the error clears and does not return, it may have been a transient glitch.
- Check the enclosure for any signs of physical damage - burnt components, corrosion, or visible wire damage.
- If the error persists across multiple reboots with no visible damage, the unit has an internal hardware fault. Contact support for a replacement or repair.
¶ Error 002 - GPIO Expander Failure (GPIO_EXPANDER)
LED: Solid red
Severity: Critical - device cannot function
The GPIO expander IC did not respond on the I2C bus during startup.
- I2C bus failure (check Error 001 first - both may appear together)
- Expander IC damaged or incorrectly addressed
- Power supply issue preventing the IC from powering up
- Check for Error 001 first. If both are active, resolve the I2C bus issue - the GPIO expander error may clear automatically once the bus is healthy.
- Power cycle the device and observe whether the error returns immediately.
- If Error 002 appears alone and persists, the GPIO expander IC is likely faulty. Contact support for a repair or replacement.
LED: Solid red
Severity: Critical - device identity unavailable; contact support
The manufacturing record stored in the Core Tap is missing, has an invalid number, or has a checksum error. This record contains the product code, hardware version, and serial number shown on the System tab. Without it, the Device ID, Hardware Version, and other identity fields will show as unavailable in the web interface.
Game logic, audio, lighting, and tag scanning are not affected by this error, but the device should not be put into a permanent installation until the record is restored.
- Device was never provisioned at the factory (pre-production or prototype unit)
- Data was corrupted by a power interruption during a factory write
- GPIO expander failure (Error 002) - the EEPROM is hosted on the same chip
- Check for Error 002 (GPIO expander failure). If the expander is not working, the EEPROM is unreachable - resolve that error first.
- There is nothing a user can do to fix this in the field. The EEPROM record must be written using factory provisioning tools. Contact support and provide the device's label serial number so the record can be reprogrammed.
These errors indicate that the audio hardware could not be initialised. Audio playback will not work until the fault is resolved, but the device can still scan tags and run game logic.
LED: 1 red blink
Severity: High - audio playback unavailable
The audio DAC board did not respond during startup. The DAC board is a small daughterboard that connects to the right side of the Core Tap and drives the speaker output.
- DAC board not seated correctly in its connector
- Loose or damaged ribbon/header connector between the Core Tap and the DAC board
- DAC board is faulty or has been damaged
- I2C bus fault (Error 001) preventing communication - check for that error first
- Open the System tab and confirm only Error 100 is active. If Error 001 is also active, resolve the I2C issue first.
- Power off the device completely (remove power, do not just reboot).
- Inspect the DAC board connection. Ensure the board is fully and evenly seated in its connector with no bent or missing pins.
- Reconnect the board, apply power, and check whether the error clears.
- If the error persists after reseating, test with a known-good DAC board. If a replacement board resolves it, the original DAC board is faulty. Contact support for a replacement.
These errors relate to the SD card or the internal flash filesystem. Most are user-resolvable by checking the card, its formatting, or the settings file.
LED: 2 red blinks
Severity: Medium - SD card features unavailable (audio, files, auto-load)
The device detected an SD card but could not mount the FAT32 filesystem on it. Audio playback from the card, the file browser, settings auto-load, and profile management will not work.
- SD card is not fully inserted
- SD card is formatted with an incompatible filesystem (e.g. exFAT, NTFS, or unformatted)
- SD card is corrupted or has bad sectors
- SD card is not compatible with the device (very high-capacity or UHS-II cards are not supported)
- Remove and re-insert the SD card, ensuring it clicks into place fully.
- Check the filesystem. Insert the card into a computer. It should appear as a FAT32 volume. If it shows as exFAT or NTFS, reformat it:
- On Windows: right-click the drive ? Format ? File system: FAT32
- On macOS: use Disk Utility ? Erase ? Format: MS-DOS (FAT)
- Test with a different SD card (any standard Class 10 microSD card up to 32 GB formatted FAT32 is recommended).
- Reboot after inserting a correctly formatted card. The error should clear automatically.
LED: 2 red blinks
Severity: High - web interface assets may not load correctly
The internal SPIFFS flash partition (used to store the web interface and firmware assets) could not be mounted. This is an internal storage fault and is not related to the SD card.
- Flash partition table mismatch after a firmware update
- Flash memory corruption
- Interrupted firmware flash during a previous update
- Perform a firmware re-flash using the full firmware package provided by support. This re-writes the partition table and SPIFFS image.
- If re-flashing is not possible via the web interface (because the UI fails to load). Contact support for repair.
- If the error persists after a clean flash, the internal flash memory may be damaged. Contact support for a replacement unit.
LED: 2 red blinks
Severity: Medium - file access unreliable
The SD card was mounted successfully but a read operation failed during use. This typically indicates a degraded or failing card.
- SD card is developing bad sectors
- Poor contact between the card and the slot (dirt, oxidation)
- Card is being removed while data is being read
- Marginal power supply affecting card operation
- Remove the card and clean the contacts with a dry cotton swab.
- Re-insert the card firmly and reboot.
- Run a filesystem check on the card from a computer (Windows:
chkdsk /f, macOS: Disk Utility ? First Aid).
- Replace the card if the error recurs. SD cards have a limited write lifespan and can degrade over time. Use a new Class 10 microSD card up to 32 GB, formatted FAT32.
LED: 2 red blinks
Severity: Low - device runs with previous (NVS-stored) settings
The auto-load feature is enabled but a settings JSON file found on SD could not be loaded at boot. The device will continue running with its last saved settings from internal NVS storage. This error is raised if:
- One or more JSON files in
/settings are invalid or cannot be applied
If the card is inserted but settings were not applied:
- Go to the System tab ? SD Card - Active Config ? click Save Settings to SD Card.
- This writes a backup to
/settings/coretap-settings.json.
- Keep the file in
/settings (top-level, not in subfolders) and reboot.
If the file exists but is corrupt:
- Insert the card into a computer and validate JSON files in
/settings (top-level only). Each file should begin with { and end with }.
- If a file is damaged, replace it with a known-good file such as
/settings/coretap-settings.json.
These errors mean the Core Tap cannot communicate with the Tap Point NFC sensor over the wired link. Without the Tap Point, no tags can be scanned.
LED: 3 red blinks
Severity: High - no NFC scanning possible
The Core Tap sent startup messages to the Tap Point but received no response within 10 seconds. The Tap Point is either not connected, not powered, or not yet running firmware that speaks the expected protocol.
- Cable between the Core Tap and Tap Point is not connected or has come loose
- Tap Point is not receiving power
- Tap Point firmware is not installed or is incompatible with the Core Tap firmware
- TX/RX wires reversed in the cable
- Check the cable connecting the Core Tap to the Tap Point. Ensure both ends are firmly seated.
- Inspect the cable for damage - kinks, cuts, or pulled-out wires.
- Verify the Tap Point is powered. Its status LED should be lit or blinking. If it shows no signs of life, check its power supply.
- Reboot both devices (power off completely, then power back on). The Core Tap will retry discovery on boot.
- Check firmware versions. The Tap Point firmware version is shown on the System tab under System Information ? Tap Point Firmware once connected. If the Tap Point has never been programmed, flash the Tap Point firmware using the Tap Point firmware update procedure.
- If the cable and power are confirmed good and the error persists, try a replacement cable.
LED: 3 red blinks
Severity: High - NFC scanning stopped mid-session
The Tap Point was communicating successfully after boot but has since stopped responding. This error is raised when the communication link goes silent after an established connection.
- Cable was accidentally disconnected during operation
- Power to the Tap Point was interrupted
- Cable damaged by being walked on, pinched, or caught on something
- Check the cable - this is the most common cause. Trace the cable from the Core Tap to the Tap Point and confirm both connectors are seated.
- Check the Tap Point for power. Its status LED should be active.
- Reboot both devices. Once the Tap Point reconnects, Error 301 will clear automatically and Error 300 will not be raised if the link is re-established within the 10-second boot window.
- If the cable was pulled out and reinserted, a reboot is required - the Core Tap does not currently hot-reconnect without a restart.
These errors indicate that the Wi-Fi or web server subsystem failed to start. The device can still scan tags and run game logic; only the web interface and network-dependent features are affected.
LED: 4 red blinks
Severity: Medium - web interface unreachable
The Wi-Fi driver failed to initialise or start. This is uncommon and is usually caused by invalid stored network configuration or a driver crash.
- Stored Wi-Fi credentials are malformed or reference a network that causes the driver to fail
- NVS (non-volatile storage) corruption affecting network settings
- Very rare: firmware issue in the Wi-Fi driver
- Reboot the device. A transient driver crash will often clear on the next boot.
- If the error persists, perform a factory reset. You can do this from the web interface if it is reachable, or trigger the boot-time sequence by powering on while holding the user button for 5 seconds, releasing it, then holding it again for 5 seconds. This clears all stored settings. If an SD card is inserted at the time of the reset, SD auto-load is automatically disabled so the card's settings aren't immediately reloaded - see SD auto-load after a factory reset.
- After the reset, reconnect to the hotspot (
CoreTap-XXXX) and reconfigure the network from scratch.
- If the error returns after every reboot even with no stored network settings, reflash the firmware. Contact support for the firmware package.
LED: 4 red blinks
Severity: Medium - web interface unreachable
Wi-Fi started successfully but the HTTP server failed to launch. The web configuration interface will not be accessible. Tag scanning and game logic continue to operate normally.
- Insufficient free heap memory (can occur if other components consumed more memory than expected)
- Port conflict (very rare - the server uses port 80)
- Firmware bug
- Reboot the device. Memory fragmentation clears on restart.
- If the error returns reliably after every boot, reflash the firmware using the latest version from support.
- If the error still returns after a clean flash, contact support - the device may have insufficient RAM for the current firmware build.
These errors indicate that an on-board sensor is not responding. The device continues to operate normally for all game functions; only the affected monitoring feature is unavailable.
LED: 5 red blinks
Severity: Low - temperature monitoring unavailable, all other functions normal
The I2C temperature sensor did not respond during startup or is returning invalid data. The board temperature reading on the System tab will show as unavailable. All game functions (tag scanning, audio, lighting, web interface) continue to work normally.
- I2C bus issue (check for Error 001 - it would take priority and show a solid red LED)
- TMP102 sensor chip damaged or failed
- Solder joint failure on the sensor (rare)
- Check for Error 001. If the I2C bus itself is faulty, fix that first.
- Reboot the device. If the sensor was in a bad state at power-on, it may recover.
- If the error persists, the sensor has likely failed. Since all game functions still work, the device can remain in service and the error monitored.
- For a permanent fix, contact support for a repair.
If you have followed the steps above and an error persists, collect the following information before contacting support:
- The exact error code number shown on the System ? Active Errors panel
- The firmware version (System tab ? System Information)
- A description of when the error first appeared and whether anything changed at that time
- Any other active errors shown alongside the one you are troubleshooting