mono output and gpio buttons to control speaker

[Greylinux]

Hi ,

@rern I've only just found your project and seriously its amazing , to give you a quick background I've tried several software options , Moode audio , Volumio, HifiberryOS, etc etc . Ive even made my own arch linux arm build using just plain mpd using an mpd client to control , but everything seemed lacking in the UI department .

I stumbled upon your project after discovering rune audio was still being actively developed, albeit with forks such as yours and I'm seriously impressed, also its all built off Arch Linux 😍

now to the matter in hand firstly I have my Hifiberry amp2 wired to be a mono speaker I convert the output into mono using the asound.conf file , however when I edit this file it defaults back to the previous file upon reboot , do you have an alternative way that I can convert the output to mono ? or maybe allow config of the asound.conf file ?

this is my config if it helps someone or they are interested .

pcm.card0 {
type hw
card 0
}

ctl.card0 {
type hw
card 0
}

pcm.monocard {
slave.pcm card0
slave.channels 2
type route
ttable {
# Copy both input channels to output channel 0 (Left).
0.0 0.5
1.0 0.5
# Send nothing to output channel 1 (Right).
0.1 0
1.1 0
}
}

ctl.monocard {
type hw
card 0
}

pcm.!default monocard
ctl.!default monocard

now to the second matter , I currently control the speaker using gpio attached buttons that utilise a python script run as a service that wait for the rising edge of a button press and sort of filter out ghost presses that tend to happen with mechanical buttons.

its a very simple script that works with out issue, would you be interested in adding it as an option in your build ? possibly with an option in the UI to enable it ?

here is the script

#!/usr/bin/python


import RPi.GPIO as GPIO
import sys
import time
import os
import subprocess

# Use SoC pin numbering
GPIO.setmode(GPIO.BCM)

#configuration of pins
SW_TOGGLE = 26
SW_VOL_UP = 27
SW_VOL_DN = 23

bounce_time = 500

GPIO.setup(SW_TOGGLE, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(SW_VOL_UP, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(SW_VOL_DN, GPIO.IN, pull_up_down=GPIO.PUD_UP)

if GPIO.input(SW_TOGGLE) == 1:

    def switch_event_toggle(event):
        time.sleep(0.005)
        # only deal with valid edges
        if GPIO.input(event) == 1:
            subprocess.call(['mpc', 'toggle' ])
            #print ('TOGGLE')

    GPIO.add_event_detect(SW_TOGGLE, GPIO.RISING, callback=switch_event_toggle, bouncetime=bounce_time)

if GPIO.input(SW_VOL_UP) == 1:

    def switch_event_vol_up(event):
        time.sleep(0.005)
        # only deal with valid edges
        if GPIO.input(event) == 1:
            subprocess.call(['mpc', 'volume', '+1' ])
            #print ('VOLUME UP')

    GPIO.add_event_detect(SW_VOL_UP, GPIO.RISING, callback=switch_event_vol_up, bouncetime=bounce_time)

if GPIO.input(SW_VOL_DN) == 1:

    def switch_event_vol_dn(event):
        time.sleep(0.005)
        # only deal with valid edges
        if GPIO.input(event) == 1:
            subprocess.call(['mpc', 'volume', '-1' ])
            #print ('VOLUME DOWN')

    GPIO.add_event_detect(SW_VOL_DN, GPIO.RISING, callback=switch_event_vol_dn, bouncetime=bounce_time)

# Main
while True:
    time.sleep(1)

and here is the simple service file I use to start the script at boot

[Unit]
Description=gpio button script 
After=multi-user.target

[Service]
Type=idle
ExecStart=/usr/bin/python3 /home/alarm/gpio-buttons.py

[Install]
WantedBy=multi-user.target

utilise these as you see fit, I hope this possibly improves the project further .

kind regards

[Greylinux]

I should also mention that in order for the gpio script to work python3-rpi-gpio needs to be installed from AUR

[Greylinux]

I see that this will be a lot harder to implement than i first thought, Ive tried editing the relevant line in mpd-conf.sh , mpd-devices.sh and /etc/asound.conf to allow for mono output. Sometimes it works and I can get mono output but then volume control breaks and I cant load the player tab it seems changing /etc/asound.conf breaks the settings.php for the player tab as it claims an unknown variable.
after reboot /etc/asound.conf becomes unreadable as something alters the file with multiple 0's in places .

I hope that eventually mono output can be added to Raudio-1 so I can use it , as I really really like the project , I will tinker around and see if I can get it working but my experience is very limited . However 🤞

[Greylinux]

I managed to get the gpio script working, however to install python3-rpi-gpio I had to change to the alarm user and install , as makepkg doesnt allow root to install from AUR

[Greylinux]

I'm not sure if its possible to use sox resampling in Raudio-1 , I've discovered that the moode audio project use sox resampling to create mono output not entirely sure how , but did see an article that might help here