The LED indicator normally flashes to indicate disk activity.
Upon initial power-on, the activity LED also reports following status conditions:
1 fast blink on boot: Firmware successfully loaded, and at least one image file loaded successfully
3 fast blinks: No images found on SD card, and then automatically falls back to raw passthrough mode.
5 fast blinks: SD card not detected
Continuous morse pattern: firmware crashed, morse code indicates crash location
No LED activity: verify the 'BOOT' configuration switch is OFF
If a crash occurs, the firmware will also attempt to save information to a separate zuluerr.txt log file, on the root of the SD card.