Linux Volume Control for Nano. Slider , ALSA and Pulse compatible -- Windows
This is mainly developed for Nano. Slider, but it can be fairly easily used with any Midi based potentiometer. It is written in python3.
Options:
| Command | Info |
|---|---|
| -p | Pulse |
| -a | Alsa |
| -d | Debug mode(produces a .log) |
| -t | Set .json file |
| -e | Elementary OS mode(Icons work different on Elementary OS) |
| --bento | NanoBento Notification Icon |
| --wavez | NanoWavez Notification Icon |
| --mizu | NanoMizu Notification Icon |
This version has per app control when using pulse, it can be configured via the config.json,to add more apps.In order to make it work we have to change some things on the qmk keymap,instancitate an app variable as 0x3E,uint8_t app = 0x3E; , on slider function we have to change midi_send_cc to midi_send_cc(&midi_device, 2, app, 0x7F - (analogReadPin(SLIDER_PIN) >> 3)); and last use the macro utility to change app value to what ever is configured in the config.json
ex:
uint8_t app = 0x3E;
// Defines the keycodes used by our macros in process_record_user
enum custom_keycodes {
QMKBEST = SAFE_RANGE,
SPOTIFY,DISCORD
};
bool process_record_user(uint16_t keycode, keyrecord_t *record) {
switch (keycode) {
case SPOTIFY:
if (record->event.pressed) {
// when keycode SPOTIFY is pressed
app= 0x3F;
} else {
app= 0x3E;
// when keycode SPOTIFY is released
}
break;
case DISCORD:
if (record->event.pressed) {
// when keycode SPOTIFY is pressed
app= 0x40;
} else {
app= 0x3E;
// when keycode SPOTIFY is released
}
break;
}
return true;
}
void slider(void) {
if (divisor++) { // only run the slider function 1/256 times it's called
return;
}
midi_send_cc(&midi_device, 2, app, 0x7F - (analogReadPin(SLIDER_PIN) >> 3));
}
It is provided as is, and it comes with no guarantee.(see Licence)
Nevertheless any change, update or upgrade is welcomed.
This project uses the following libraries:
- pulsectl: https://pypi.org/project/pulsectl/
- pyalsaaudio: https://pypi.org/project/pyalsaaudio/
- python_rtmidi: https://pypi.org/project/python-rtmidi/
TODO
- Add auto launch on boot
- Proper installer
- Add Hot-Plug support
- Test stability
- Allow control when changing audio output Devices(on Pulse only)
- Allow per App control
How to install
Install git & python3 & pip3
sudo apt install git python3 python3-pip
Import repository(on /home/USER directory , where USER is your user name)
git clone https://github.com/jesusvallejo/Midi2Vol-Linux/
Install requirements
sudo apt-get install libasound2-dev
sudo apt-get install libjack-dev
sudo apt install libappindicator3-dev
cd /home/USER/MidiDev/
pip3 install -r requirements.txt
To launch on boot create a file called midi2vol.sh and edit with(where USER is your user name, And -X is either -a for Alsa or -p for Pulse edit accordingly):
#!/bin/bash
sleep 5 && python3 /home/USER/MidiDev/midi2vol.py -X |& tee -a /home/USER/MidiDev/midi2vol.log;
Then crontab -e and paste this(remember to edit USER with your user name):
@reboot bash /home/USER/MidiDev/midi2vol.sh
And last add your user to the audio group (remember to edit USER with your user name):
sudo usermod -a -G audio USER
PS: I could not make it work as a service, still working on it
After some time i figured out the problem was not running the service as the logged user so: Add USER to audio and pulse groups:
sudo usermod -a -G audio USER
sudo usermod -a -G pulse USER
Example:
sudo usermod -a -G audio jesus
sudo usermod -a -G pulse jesus
Add this file:
sudo nano /etc/systemd/system/midi2vol.service
Fill with:
[Unit]
Description=midi2vol service.
[Service]
User=USER
Type=simple
ExecStart=/usr/bin/python3 /home/USER/MidiDev/midi2vol.py -p
[Install]
WantedBy=multi-user.target
EX: (NOTE IN THE EXAMPLE -d IS ACTIVE, THIS ENABLES LOGGING, REMEMBER CHANGING THE PATH ON THE CODE OR IT WONT HAVE RIGHTS TO DO SO)
[Unit]
Description=midi2vol service.
[Service]
User=jesus
Type=simple
ExecStart=/usr/bin/python3 /home/jesus/MidiDev/midi2vol.py -p -d
[Install]
WantedBy=multi-user.target
Reload and start
sudo systemctl daemon-reload
sudo systemctl start midi2vol.service
sudo systemctl status midi2vol.service (if everything ok continue)
sudo systemctl enable midi2vol.service (this makes it run each boot)
If you are on a Ubuntu distro(or based on it ex: elementary os), you can make it easier by System settings/Applications/Startup/+ and type in box 'Type in a custom command':
/usr/bin/python3 /home/USER/MidiDev/midi2vol.py -p
Some Q/A regarding code:
Why is there two time.sleep()?
- Well , first one time.sleep(10) helps to let (what i think) pulse audio completely init and avoid not having per app volume control, to this moment i still dont know why this happens but 10 seconds at start up not having volume control with the nano. slider seems a good trade for having per app volume control(will implement a flag so its only when per app control is wanted), and the second one is to avoid wasting cpu when theres no actual change on the nano slider potentiometer.
Can i make my own .json?
- Yes of course you can as long as it parses and follows the default one,pretty easy to add/delete apps. Remember that your keymap has to send the correct hex to work. Also if you loose it the file will be auto generated, and in case it does not work it will make a .bak before creating a new working one.
Does alsa work as pulse?
- Yes and no, alsa only has default device control, and pulse has all sink control and per app control, which means even if you change the output device will work, it wont with alsa.