HO523 Theory of Operation
This section describes how specific components operate on the HO523.
On-Board LEDs
There are four on-board LEDs that indicate the following:
LED | Indication |
|---|---|
Green file-system activity (Bsy) | Flashes any time there is file-system activity (on any storage device) |
Green power (Pwr) | Displays when the board is powered up and not in reset mode. Flashes during firmware update process. |
Blue WiFi (WiFi icon) | Flashes when the player is connecting to the wireless network. Displays when connected. |
Red status (Err) | Flashes a certain number of times to indicate which error is occurring. The flash codes are described below. |
| 2: Unspecified error |
| 3: Network recovery script is preparing to run on a device configured for network recovery. |
| 4: No upgrade file found. |
| 5: Failed to load kernel module. |
| 6: Board is not capable of running the current firmware version. |
| 7: A piece of on-board hardware is not working correctly. |
| 8: Problem related to the storage device (either the USB drive or microSD card) |
| 9: Problem related to the registry/NAND |
| 10: The autorun script encountered a load/run error. |
| 11: WiFi-related error |
| 12: Unable to find a bootable image. |
On-Board Switch
The on-board switch is connected to the GPIO12, which is pulled low when the service (SVC) button is pressed. Conversely, a pull-up on the button normally sets the GPIO12 to be pulled high.
Reset Switch / GPIO Button
The on-board switch is connected to the reset circuit. Pressing down the reset button will send an initial signal to the system software, and holding the reset button low for approximately 4 seconds will cause a hard reset.
microSD Slot
The HO523 has one microSD slot, which supports transfer modes up to UHS-1 DDR50 (50MB/s). There is no inherent limit on the storage capacity of microSD cards used with the player.
Wireless Module
The HO523 has an internal M.2 slot for installing a compatible wireless module. The M.2 wireless module connects via cable to a single external, attachable wireless antenna.