E3 — RFID_SPI_BUS_INIT_FAILED

Hardware version

This error only occurs on v3 hardware.

The SPI exclusive-device wrapper for the RFID reader failed to initialise (CS pin could not be set high).

What happens

rfid_task exits immediately. RFID scanning is unavailable for this session. All other firmware tasks continue normally.

Possible causes

• Setting the chip-select (CS) pin high failed during bus setup, which indicates a GPIO or shift-register issue.
• Flash or firmware corruption produced invalid pin assignments.

How to fix

1. Reboot the device — A fresh boot retries the whole rfid_task setup.
2. Reflash the firmware — Flash the latest firmware using espflash.
3. Contact support — If this error appears consistently, open an issue on GitHub.