`Available` means Linux can access `/dev/spidev3.0`. Use `Test PING` to confirm ESP32 is actually responding.
Good response usually shows `00deadbeef`. Health becomes `Healthy` and fail streak returns to `0`.
Red banner means no response from the slave device. Check ESP32 power, SPI wiring, and matching CRC mode.
ESP32 and Orange Pi must use the same CRC mode (`none`, `crc16`, `crc32`, or `both`). Mismatch can show no-response or CRC errors.
Confirm MOSI/MISO/SCLK/CS are on the configured pins, shared GND is present, and ESP32 is powered before testing PING.
Uploads store files on Orange Pi at `~/Orange_Pi_RV2/data/files` and metadata in `~/Orange_Pi_RV2/data/orangepi.db`.
Single-file upload limit is 512 KB from this UI. If upload fails, check free disk space and API service status.
SPI: `/api/spi/status`, `/api/spi/ping`, `/api/spi/configure`. Files: `/api/files/list`, `/api/files/upload`, `/api/files/stats`.
Tip: press Esc to close this menu. You can reopen it from the floating `?` button.