Hi!
I’m a long time user of Volumio. Love it.
In a new system I have an old receiver with sleep function. I would like Volumio to stop playing when the amp goes to sleep. I can think of 1 way:
I power the RPI 4 via the usb on the receiver. When it shutsdown the power wil be cut. Not very sophisticated, I know. Here I will use an usb dac wich will be externally powered.
I know there will be a small chance of corrupting the SD card. Any other problems with this scenario?
Cheers!
Peter
not really, (besides the SD card corruption) but I doubt that the amp can power the rpi adequate.
the rPi4 requires 3A, pretty sure the amp can’t deliver that
you can use the 5V of the receiver USB port as a signal to trigger the shutdown of the Raspberry Pi (when 5V is removed) or to boot the Raspberry Pi (when the 5V is applied again).
Please be aware it requires some additional components to make it working, connecting directly the 5V to a GPIO of the Raspberry Pi will damage it.
Smart one!
something like:
and replace the switch by a relay operated by the amp.
Yes it can! Although te usb port says 5v, 1a, it works!
Is there any damage or degradation in audio quality when things get underpowerd?
Dutch?
Yes it will cause unstable behaviour, weird unexpected errors, hickups, SD-Card corruption
Ah that sounds interesting!
I’m a total electronics noob though (just googled what a relay is. Now I know).
Would it be something like this:
Yes, Dutch!
similar principle, but not exactly this
the RPi will be always powered, but the circuit should “translate” the presence or absence of the 5V from the USB of the receiver into a signal that mimics the press of a button, connected to two GPIOs of the RPi.
But then next time you want to play music you’d have to turn on the receiver and wait for a few min for the RPi to boot? That seems inconvenient.
I don’t know what your ultimate goal is, but consider what happens if you turn off the receiver, and then do nothing - don’t touch volumio at all. It will continue playing until it reaches the end of playlist or album. That way next time you turn the receiver on - just pick a song and press play.
My volumio rPi has been on for a year.
I often listen to internet radio when going to sleep, so these playlists are endless.
tweemeter sessies 
There may be another way: power the usb dac from your amplifier, not the PI. Write a script which polls the existence of the usb dac device every few minutes by parsing the output from “aplay -l”.
Then, when the device goes “missing”, shutdown the PI with a normall “poweroff”.
You may need to cut the 5v line from the usb cable between the dac and PI.
Maybe you can use this…it cuts off the power raspberry pi.
The only drawback is that it must be controlled with a minimum of 7 volt power supply.
it works with audiophonics on off plugin.
it works just the other way around than what you want. so this is probably not the solution you are looking for.
Sounds good, also. Know idea how to do that yet, but I’ll look into it!
Hi Peter,
Use a master/slave powerstrip.
See Conrad or Hornbach for Brennensthuhl.
Regards,
Arieknarie