LEDsΒΆ
The Duckbill is equipped with a two-color status LED at the bottom side. Each color of the LED is wired to a dedicated GPIO pin of the CPU. As usual in Linux, both colors are modelled as individual LED in the BSP.
During boot process, U-Boot switches the red status LED on shortly to indicate that a software component is running at all. When linux kernel takes over, it flashes the green status LED like a heartbeat, to indicate that the kernel is still alive and running.
| Attribute | Status LED | |
|---|---|---|
| Color | red | green |
| Linux Device | /sys/class/leds/duckbill:red:status | /sys/class/leds/duckbill:green:status |
| Default trigger | none | heartbeat |
The following table lists various device states.
| Status LED | Duration of this state | Status / possible solution | |
|---|---|---|---|
| red | green | ||
| off | off | persistent | Device is powered off, attach power supply |
| on | off | < 10s | U-Boot is running and loading Linux |
| on | flashing | < 25s | Linux kernel is booting |
| on | off | persistent | U-Boot could not start Linux |
| off | flashing | persistent | Linux system is running |
| on | flashing | persistent | Linux system is running, but errors during initialization |
Additionally, the Duckbill 485 has two single LEDs on left and right side of the case. The LEDs are handled by the ser2net application via sysfs. They indicate RS-485 operations by flashing and are operational after a socket connection to ser2net has been established.
| Attribute | TX LED | RX LED |
|---|---|---|
| Color | red | green |
| Linux Device | /sys/class/leds/duckbill:red:rs485 | /sys/class/leds/duckbill:green:rs485 |
| Default trigger | none | none |
