LEDs

NMHW21 provides four LEDs that can be controlled by user application or via command line.

The LEDs are described as follows:

  • Indicator onboard (ind)
  • Status onboard (status)
  • Indicator user-interface (ind ui)
  • Status user-interface (status ui)

Standard LED behavior

On startup (during bootloader/system-boot) the LEDs follow a specific pattern. During the startup the LEDs on the user-interface and the onboard LEDs are synced.

‘ind’ = ‘ind ui’
‘status’ = ‘status ui’
  • start of the bootloader (hard coded into u-boot)
ind - red
status - red
  • start of kernel (defined in the device tree)
ind - off
status - orange

Hard reset

On a hard reset the onboard status LED starts orange.

LED: PCB Ind

Green

$ echo 1 > /sys/class/leds/ind\:green/brightness
$ echo 0 > /sys/class/leds/ind\:red/brightness

Orange

$ echo 1 > /sys/class/leds/ind\:green/brightness
$ echo 1 > /sys/class/leds/ind\:red/brightness

Red

$ echo 0 > /sys/class/leds/ind\:green/brightness
$ echo 1 > /sys/class/leds/ind\:red/brightness

Off

$ echo 0 > /sys/class/leds/ind\:green/brightness
$ echo 0 > /sys/class/leds/ind\:red/brightness

LED: PCB Status

Green

$ echo 1 > /sys/class/leds/status\:green/brightness
$ echo 0 > /sys/class/leds/status\:red/brightness

Orange

$ echo 1 > /sys/class/leds/status\:green/brightness
$ echo 1 > /sys/class/leds/status\:red/brightness

Red

$ echo 0 > /sys/class/leds/status\:green/brightness
$ echo 1 > /sys/class/leds/status\:red/brightness

Off

$ echo 0 > /sys/class/leds/status\:green/brightness
$ echo 0 > /sys/class/leds/status\:red/brightness

LED: UI Ind

Green

$ echo 1 > /sys/class/leds/ui\:ind\:green/brightness
$ echo 0 > /sys/class/leds/ui\:ind\:red/brightness

Orange

$ echo 1 > /sys/class/leds/ui\:ind\:green/brightness
$ echo 1 > /sys/class/leds/ui\:ind\:red/brightness

Red

# echo 0 > /sys/class/leds/ui\:ind\:green/brightness
$ echo 1 > /sys/class/leds/ui\:ind\:red/brightness

Off

# echo 0 > /sys/class/leds/ui\:ind\:green/brightness
$ echo 0 > /sys/class/leds/ui\:ind\:red/brightness

LED: UI Status

Green

$ echo 1 > /sys/class/leds/ui\:status\:green/brightness
$ echo 0 > /sys/class/leds/ui\:status\:red/brightness

Orange

$ echo 1 > /sys/class/leds/ui\:status\:green/brightness
$ echo 1 > /sys/class/leds/ui\:status\:red/brightness

Red

$ echo 0 > /sys/class/leds/ui\:status\:green/brightness
$ echo 1 > /sys/class/leds/ui\:status\:red/brightness

Off

$ echo 0 > /sys/class/leds/ui\:status\:green/brightness
$ echo 0 > /sys/class/leds/ui\:status\:red/brightness