XS156 Theory of Operation
This section describes how specific components operate on the HD225 and HD1025.
On-Board LEDs
The four on-board LEDs have the following indicators:
LED | Indication |
|---|---|
Green power (Pwr) | Displays when the board is powered up and not in reset mode. Flashes during the firmware update process. |
Green file-system activity (Bsy) | Flashes any time there is file-system activity (on any storage device) |
Blue WiFi (WiFi icon) | Flashes when the board is being updated |
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 / SVC Button
The on-board switch is connected to the GPIO02, which is pulled low when the service (SVC) button is pressed. Conversely, a pull-up on the button normally sets the GPIO02 to be pulled high.
Reset Switch / GPIO Button
The on-board switch is connected to the reset circuit. Pulling low on the Reset button for less than 2 seconds will initiate an orderly system reset under software control at the rising edge of the signal. If the Reset button is pulled low for more than 6 seconds, an immediate hard reset is performed.
SDIO Slot
The XS156 provides one SD card interface capable of UHS-1 operation at up to DDR50 transfer rates. A +3.3V power supply is provided for the card. This power supply can be switched on and off by the firmware, allowing it to power-cycle the SD card.
Wireless Module
The XS156 has an M.2 E Key for WiFi/Bluetooth modules.