How to disable blue (power)LED on PowerDock2? & expled not working properly?

Vukan Vuk

Hi guys,

I'm new to omega but I was wondering if someone can help me out with turning off the blue LED (power indicator, I'm guessing) light on the PowerDock2? Or maybe show me in which file the settings are...

Additionally, I tried messing around with the expled command, but it just changed the flickering lights of the battery level indicator. Also it did not change the colors, as explained in those docs. Also, now that the flickering is messed up, can someone give me the default values, so I can revert back to normal again?

All the best,

CAP 33

I do not know for sure, but I think that it is impossible to turn off the blue LED, as it turns on when power is applied to PowerDock2.

György Farkas

@Vukan-Vuk Yes, @CAP-33 is correct - you can not turn off the POWER LED of Power Dock without some hardware action / modification.

The expled tool - originally - is able to control the RGB LED of an Expansion Dock via GPIO15, 16, 17.
See also Expansion Dock > Using the Dock > Controlling the RGB LED

Power Dock 2 has a virtual PB (PushButton) that we can push with the power-dock2 utility via GPIO16 (or unintentionally because GPIO16 is floating by default ;-).
See also Checking the Battery Level

Up to now I thought that PB is effective only if a battery is connected to the board.
It seems you have found a creative way when you are keep pushing it with an expled command - theoretically 200 times per second ;-).

You should try to stop the PWM signal on GPIO16 with fast-gpio set-input 16 - this was the default state of GPIO16.

Notes to @Lazar-Demin
Software PWM on the Omega’s GPIOs

Using the Omega’s GPIOs > Fast-GPIO > Generating a PWM signal on a GPIO:

Generate a software-based Pulse Width Modulated (PWM) signal on a selected pin. Specify the desired duty cycle and frequency of the PWM signal.
fast-gpio pwm <gpio> <freq in Hz> <duty cycle percentage>
This will launch a background process that will generate the PWM signal.
...
To stop the PWM signal, set the GPIO’s value:
fast-gpio <gpio> 0

Correctly:
fast-gpio set <gpio> 0 - set the output LOW (if there's an active LOW LED then it will be ON) or
fast-gpio set <gpio> 1 - set the output HIGH (if there's an active LOW LED then it will be OFF).

# Omega2+ v0.2.2 b201

root@Omega-99A5:~# expled 0xf21133
Setting LEDs to: f21133
Duty: 6 94 80

root@Omega-99A5:~# ps | grep fast-gpio
 4641 root      1160 S    fast-gpio pwm 17 200 6
 4644 root      1160 S    fast-gpio pwm 16 200 94
 4647 root      1160 S    fast-gpio pwm 15 200 80
 4761 root      1188 S    grep fast-gpio

Are these fast-gpio pwm ... processes running in the background really?