GPIO amplifier control


Hi, I did my best to search this forum for answer with no success.

I’m trying to find a way how to turn on and off amplifier using raspberry’s GPIO. Hardware is no problem. But I would like to know if there is a way how to control GPIO based on Mopidy activity? Like linking status “is playing” to GPIO, or to have a set of scripts running when stream started/stopped.

I found there is complex API for Mopidy, but that is far beyond my skills.

Any ideas? Thank you.


I wouldn’t call the API complex, in fact I found it very easy to start with writing my own code :slight_smile: To run some code on player state changes just create a class deriving from mopidy.core.CoreListener and implement playback_state_changed method (docs:

Or You can take another aproach which I did and use pulseaudio events - this approach is better if You plan to use other audio sources on Your device (for example bluetooth playback or spotify connect). I wrote simple python script to handle this: If You use only alsa there is also a way to do same thing but You need to dig the internet for the solution.


Your pulse event solution is nice, not come across that before.



is there any foolproof guide how to implement it to PiMusicBox? You know… for a fool.



Hm, yeah, I am making strongly use of mosquitto and my mosquitto-frontend (and openHab) and I do something similar.

It works like this, openhab turns on the speakers by a let’s say mosquitto-heartbeat-message.
Five minutes after last the heartbeat-message the speakers/amplifier are turned off.

So you have to send the heartbeat-message e.g. every minute to keep them turned on!

This is what my frontend does - it sends a message every 30 seconds when state is playing to keep the amplifier turned on.

Of course you don’t have to use openHab. A simple python script should do the job.

If you are interested in such a solution, let me know.

Nevertheless this is how my openHab config looks like:

rule "Server Speaker Mopidy Keep Alive"
    Item Mopidy_Speaker_Keep_Alive received update

rule "Server Speakers auto timer"
    Item PCSpeakersServer received command ON
    # set the timeout back to 5 mins
    serverSpeakersTimeout= 60 ; // 5 min --> 300 / 5secs = 60
    logInfo("SrvSpkrs","Started timeout ")

rule "Every 5 seconds"
    Time cron "0/5 0/1 * 1/1 * ? *"
    if (serverSpeakersTimeout > 0)
        if (serverSpeakersTimeout==1)
        serverSpeakersTimeout = serverSpeakersTimeout - 1