RPi 3, Hifiberry AMP2, rotary encoder, on/off switch

pez

Hi Everybody,
i have managed to use a rotary encoder to change volume and play/pause, was inspired by this here:
#3665
and got some help from Bob:
https://github.com/bobrathbone/piradio

I am using the original rotary_class.py from Bob.

I am using this encoder and these pins (attachment):
https://www.conrad.at/de/encoder-5-vdc-001-a-schaltpositionen-20-360-tt-electronics-ab-1en11-hsm1af15-1-st-453405.html

I used this codes here to start:

pacman -Syy
pacman -S python2
pip install RPi.GPIO

That's the script for controlling runeaudio (mpd):

#!/usr/bin/env python
#
# Raspberry Pi Rotary Test Encoder Class
# $Id: rotary_switch.py,v 1.4 2014/01/31 14:06:26 bob Exp $
#
# Author : Bob Rathbone
# Site   : http://www.bobrathbone.com
#
# Adjusted to be used as single hardwarecontroller for rune audio and Hifiberry Amp2 by Petrus Gartler
# Date   : 2017/12/2
#
# This class uses standard rotary encoder with push switch
#

import sys
import time
import sys,os

from rotary_class import RotaryEncoder

# Switch definitions
ROT_A = 24
ROT_B = 25
ROT_BUTTON = 23

# Execute system command
def execCommand(cmd):
	p = os.popen(cmd)
	return  p.readline().rstrip('\n')

# This is the event callback routine to handle knob events
def volume_knob_event(event):
	handle_event(event,"Volume knob")	
	return

# This is the event callback routine to handle events
def handle_event(event, name):
	if event == RotaryEncoder.CLOCKWISE:
#		print name, "Clockwise event =", RotaryEncoder.CLOCKWISE
		execCommand("mpc volume +5"), RotaryEncoder.CLOCKWISE
	elif event == RotaryEncoder.ANTICLOCKWISE:
#		print name, "Anticlockwise event =", RotaryEncoder.ANTICLOCKWISE
		execCommand("mpc volume -10"), RotaryEncoder.CLOCKWISE
	elif event == RotaryEncoder.BUTTONDOWN:
#		print name, "Button down event =", RotaryEncoder.BUTTONDOWN
		execCommand("mpc toggle"), RotaryEncoder.BUTTONDOWN
#	elif event == RotaryEncoder.BUTTONUP:
#		print name, "Button up event =", RotaryEncoder.BUTTONUP
	return

# Define knob
volumeknob = RotaryEncoder(ROT_A,ROT_B,ROT_BUTTON,volume_knob_event,2)

# Wait for events
while True:
	time.sleep(0.5)

# End of program

Now i am trying to make an on/of switch but unfortunately i somehow messed around the poweroff command and can't even shutdown rune using the webinterface or terminal.
I am afraid, i deleted a file called poweroff-target. Is that something i shouldn't have done?

I hope someone can get me out without reinstalling the whole thing.

Cheers,
Pe

Attachments

: GPIO_Pi3.png (90.61 KiB) Viewed 9208 times

janui

Hi pez,

pip install RPi.GPIO

This is not the way to install a package or library on an Arch Linux system. I would expect you to do something like this:

cd /home
wget https://aur.archlinux.org/packages/ra/raspberry-gpio-python/raspberry-gpio-python.tar.gz
tar xf raspberry-gpio-python.tar.gz
cd raspberry-gpio-python
makepkg -Acs --asroot
pacman -U raspberry-gpio-python

You may get some errors with the makepkg command because Rune is a striped down version of Arch Linux. I use the following to install the extra packages needed to build packages:

pacman -Syy make gcc

And afterwards remove the extra packages with:

pacman -Rs make gcc

Finally to clean up the package build (you may want to save the files '/home/raspberry-gpio-python/*' first, with these you can reinstall with the pacman command after restoring the files without needing to use makepkg):

cd /home
rm -rf raspberry-gpio-python

I think you should also know about the overlay 'rotary-encoder' open the file '/boot/overlays/README' and search for 'rotary-encoder'. I have not used this and am not sure how it works.

And, yes, you need the file '/usr/lib/systemd/system/poweroff.target', it should contain:

#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.

[Unit]
Description=Power-Off
Documentation=man:systemd.special(7)
DefaultDependencies=no
Requires=systemd-poweroff.service
After=systemd-poweroff.service
AllowIsolate=yes
JobTimeoutSec=30min
JobTimeoutAction=poweroff-force

[Install]
Alias=ctrl-alt-del.target

janui

pez

Hi janui,
thanks for that, i created that poweroff.tagret file and it shuts down properly now when i use python to run the script.

All the GPIOs work well, so i will not reinstall that, but next time i'll do it as you recommend.

Only when i try to create a service running that script at boot time i get the following error:

root@runeaudio(rw):~/hw-control# systemctl enable hw_poweroff
root@runeaudio(rw):~/hw-control# systemctl start hw_poweroff
root@runeaudio(rw):~/hw-control# systemctl status hw_poweroff
● hw_poweroff.service - RuneAudio Poweroff
   Loaded: loaded (/usr/lib/systemd/system/hw_poweroff.service; enabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Fri 2017-12-08 14:10:40 CET; 4s ago
  Process: 1531 ExecStart=/home/root/hw-control/hw_poweroff.py (code=exited, status=203/EXEC)
 Main PID: 1531 (code=exited, status=203/EXEC)

Dec 08 14:10:40 runeaudio systemd[1]: Started RuneAudio Poweroff.
Dec 08 14:10:40 runeaudio systemd[1]: hw_poweroff.service: Main process exited, code=exited, status=203/EXEC
Dec 08 14:10:40 runeaudio systemd[1]: hw_poweroff.service: Unit entered failed state.
Dec 08 14:10:40 runeaudio systemd[1]: hw_poweroff.service: Failed with result 'exit-code'.

My service file is this here:

[Unit]
Description=RuneAudio Poweroff
After=mpd.service

[Service]

ExecStart=/home/root/hw-control/hw_poweroff.py

[Install]
WantedBy=multi-user.target

Can you tell what's going wrong?

hondagx35

Hi janui and pez,

pip install RPi.GPIO

This is not the way to install a package or library on an Arch Linux system. I would expect you to do something like this:

RPi.GPIO is not a Linux package it is a python library!
To install python libraries with pip is totally fine on Arch and Rune.

[Unit]
Description=RuneAudio Poweroff
After=mpd.service

[Service]

ExecStart=/home/root/hw-control/hw_poweroff.py

[Install]
WantedBy=multi-user.target

Python scripts cannot be started directly, you have to use something like:

ExecStart=/usr/bin/python2 /home/root/hw-control/hw_poweroff.py

BTW:
@[deleted]: I have no idea why your posts have to be approved.

Frank

pez

Hi Frank,
thanks for the clearification, everything runs perfectly now!
In another thread you mentioned to be better using another command to shutdown:

hondagx35 wrote Hi Pete,

- Python2 is installed on the newer versions by default
- you should call "/var/www/command/rune_shutdown poweroff" or
"/var/www/command/rune_shutdown reboot" before systemctl shutdown or reboot.

Frank

Why is that?

Interesting enough, i have a script running at startup for my rotary encoder which runs OK with this service:

[Unit]
Description=RuneAudio Rotary Switch
After=mpd.service

[Service]

ExecStart=/home/root/hw-control/rotary_switch.py

[Install]
WantedBy=multi-user.target

I'm fine with that, only wandering why this one doesn't need the "/usr/bin/python2" part and the other one does.

Now to the stauts LED-part,
cheers and thanks,
pez

PS.: Maybe the forum-software thinks i'm a bot, but i can assure you i'm not.

hondagx35

Hi pez,

I'm fine with that, only wandering why this one doesn't need the "/usr/bin/python2" part and the other one does.

Compare your python scripts, i bet the working one has this at the top:

#!/usr/bin/python2

and / or
it is made executable with:

chmod +x filename.py

This can be checked with:

ls -la /path-to-your-script/scriptname

In another thread you mentioned to be better using another command to shutdown:

I mentioned to call rune_shutdown before shutting down with your favorite method.
This is because the script stops MPD and unmounts your shares.

- you should call "/var/www/command/rune_shutdown poweroff" or
"/var/www/command/rune_shutdown reboot" before systemctl shutdown or reboot.

Frank

pez

The python script wasn't executable, that was it!
I included that call ".../rune_shutdown poweroff" before shutdown.
By the way, both of them have

#!/usr/bin/env python2

at the beginning but it works anyway.

Cheers, i'll keep this thread updated with my progress.
pez

pez

Hi everybody,
i am more the soldering type of guy rather than coding, so i've figured out a hardware based solution for a combined shutdown/startup switch with status LED, see attachment. It works perfectly fine with my script to shutdown via GPIO-26. It uses a relais to switch between RUN and GPIO on one side and red/green LED color on the other.
I'm planning to remove one USB connector and use it's 5V pin to control the "primary" relais circuit.
Does anybody have an idea about how to get three LEDs controlled based on the volume level as a simple volume indicator?
0%: no LED
1-33%: 1 LEDs
34-67%: 2 LEDs
68-100%: 3 LEDs

Any help is appreciated,
greetings,
P

Attachments

: RaspiHifiBox02.png (19.74 KiB) Viewed 9012 times

pez

OK, based on some other threads i got that script set up but is that the correct way to do it?
To be honest i hardly understand what i'm doing

Testing it without LEDs connected it puts out the actual volume correctly but i get some warning in the beginning (see below):

#!/usr/bin/env python2
# LED_volume.py

# IMPORTS
import sys
import time
import RPi.GPIO as GPIO

from mpd import (MPDClient)

#GPIO Setup
GPIO.setmode(GPIO.BCM)
GPIO.setup(05,GPIO.OUT)
GPIO.setup(06,GPIO.OUT)
GPIO.setup(12,GPIO.OUT)
GPIO.setup(13,GPIO.OUT)

#definitions
client = MPDClient()
client.connect('localhost', 6600)

# Poll the volumelevel and set GPIO.output accordingly

while True:

    status=client.status()

    if status['volume'] > '0': # 1st LED
        GPIO.output(05,GPIO.HIGH)
        print('volume > 0')
    else:
        GPIO.output(05,GPIO.LOW)
        print('volume = 0')

    if status['volume']>'50': # 2nd LED
        GPIO.output(06,GPIO.HIGH)
        print('volume > 50')
    else:
        GPIO.output(06,GPIO.LOW)

    if status['volume']>'75': # 3rd LED
        GPIO.output(12,GPIO.HIGH)
        print('volume > 75')
    else:
        GPIO.output(12,GPIO.LOW)

    if status['volume']>'88': # 4th LED
        GPIO.output(13,GPIO.HIGH)
        print('volume > 88')
    else:
        GPIO.output(13,GPIO.LOW)

    time.sleep(0.2) # Delay loop for 0.2 second

# disconnect
client.disconnect()

# end of programm

This is the warning for each GPIO:

LED_volume.py:13: RuntimeWarning: This channel is already in use, continuing anyway.  Use GPIO.setwarnings(False) to disable warnings.
  GPIO.setup(05,GPIO.OUT)
...

Do you coding guys have any input for me?

pez

Hey guys,
i have connected a LED to the 4th GPIO output and it acts as expected EXCEPT:
At volume level 8 the pythonscript outputs

Volume > 0
Volume > 50
Volume > 75

and at Volume level 100 the LED goes off!

Do you have an idea what's going on?
Could you give some hints what to do?

pez

Well, i am making progress, but still have weird behaviour.
At volume 100 everything is OK now, all LEDs are on.
But still: at volume 8 three LEDs are on, as if it would be between 75 and 87.
Maybe it's a python vs. python2 thing?
I am really curious about what's wrong here!

That's my current script and wiring diagramm for the volume LEDs (see attachment):

#!/usr/bin/env python2
# LED_volume.py

# IMPORTS
import sys
import time
# import os
import RPi.GPIO as GPIO

from mpd import (MPDClient)

#GPIO Setup
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)

LED1 = 05
LED2 = 06
LED3 = 12
LED4 = 13

GPIO.setup(LED1,GPIO.OUT, initial=GPIO.LOW) #1st LED
GPIO.setup(LED2,GPIO.OUT, initial=GPIO.LOW) #2nd LED
GPIO.setup(LED3,GPIO.OUT, initial=GPIO.LOW) #3rd LED
GPIO.setup(LED4,GPIO.OUT, initial=GPIO.LOW) #4th LED

#definitions
client = MPDClient()
client.connect('localhost', 6600)

# Poll the volumelevel and set GPIO.output accordingly

while True:

    status = client.status()
    volume = status['volume']

    if status['volume'] > '0': # 1st LED
        GPIO.output(LED1,GPIO.HIGH)
        print('volume = ' + str(volume))
    else:
        GPIO.output(LED1,GPIO.LOW)
        print('MUTE')

    if status['volume'] > '50': # 2nd LED
        GPIO.output(LED2,GPIO.HIGH)
        print('volume = ' + str(volume))
    else:
        GPIO.output(LED2,GPIO.LOW)

    if status['volume'] > '75': # 3rd LED
        GPIO.output(LED3,GPIO.HIGH)
        print('volume = ' + str(volume))
    else:
        GPIO.output(LED3,GPIO.LOW)

    if status['volume'] > '87': # 4th LED
        GPIO.output(LED4,GPIO.HIGH)
        print('volume = ' + str(volume))
    else:
        GPIO.output(LED4,GPIO.LOW)

    if status['volume'] == '100': # ALL LEDs
        GPIO.output(LED1,GPIO.HIGH)
        GPIO.output(LED2,GPIO.HIGH)
        GPIO.output(LED3,GPIO.HIGH)
        GPIO.output(LED4,GPIO.HIGH)
        print('volume = ' + str(volume))

    time.sleep(0.2) # Delay loop for 0.2 second

# disconnect
client.disconnect()

# end of programm

Attachments

: RaspiHifBox03.png (8.82 KiB) Viewed 4270 times

pez

OK, i tried increasing volume by 1 and it's like that from 1 to 9 the script behaves like from 10 to 90 in steps of 10.
That's why at 8 it thinks it is at 80.
What can i do about that?
Any ideas?

Cheers and merry christmas, P

hondagx35

Hi pez,

Any ideas?

You are comparing strings that means

>>> '9' > '12'
True
>>> '7777' > '8'
False
>>>

You have to convert the string to an int first.

#!/usr/bin/env python2
# LED_volume.py

# IMPORTS
import sys
import time
import sys
import RPi.GPIO as GPIO
from mpd import MPDClient

#GPIO Setup
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)

LED1 = 05
LED2 = 06
LED3 = 12
LED4 = 13

GPIO.setup(LED1,GPIO.OUT, initial=GPIO.LOW) #1st LED
GPIO.setup(LED2,GPIO.OUT, initial=GPIO.LOW) #2nd LED
GPIO.setup(LED3,GPIO.OUT, initial=GPIO.LOW) #3rd LED
GPIO.setup(LED4,GPIO.OUT, initial=GPIO.LOW) #4th LED

#definitions
client = MPDClient()
client.connect('localhost', 6600)

# Poll the volumelevel and set GPIO.output accordingly

while True:

    status = client.status()
    volume = int(status['volume'])

#    print('volume = ' + str(volume))

    if volume == 0 : # 1st LED
        GPIO.output(LED1,GPIO.LOW)
        GPIO.output(LED2,GPIO.LOW)
        GPIO.output(LED3,GPIO.LOW)
        GPIO.output(LED4,GPIO.LOW)

    if volume > 0 and volume <= 50: # 1st LED
        GPIO.output(LED1,GPIO.HIGH)
        GPIO.output(LED2,GPIO.LOW)
        GPIO.output(LED3,GPIO.LOW)
        GPIO.output(LED4,GPIO.LOW)

    if volume > 50 and volume <= 75: # 2nd LED
        GPIO.output(LED1,GPIO.LOW)
        GPIO.output(LED2,GPIO.HIGH)
        GPIO.output(LED3,GPIO.LOW)
        GPIO.output(LED4,GPIO.LOW)

    if volume > 75 and volume <= 87: # 3rd LED
        GPIO.output(LED1,GPIO.LOW)
        GPIO.output(LED2,GPIO.LOW)
        GPIO.output(LED3,GPIO.HIGH)
        GPIO.output(LED4,GPIO.LOW)

    if volume > 87 and volume < 100: # 4th LED
        GPIO.output(LED1,GPIO.LOW)
        GPIO.output(LED2,GPIO.LOW)
        GPIO.output(LED3,GPIO.LOW)
        GPIO.output(LED4,GPIO.HIGH)

    if volume == 100: # ALL LEDs
        GPIO.output(LED1,GPIO.HIGH)
        GPIO.output(LED2,GPIO.HIGH)
        GPIO.output(LED3,GPIO.HIGH)
        GPIO.output(LED4,GPIO.HIGH)

    time.sleep(0.2) # Delay loop for 0.2 second

# disconnect
client.disconnect()

# end of programm

This script gives you the following behaveor:
- volume = 0 all LEDs off
- volume between 0 and 50 only LED1 is on
- volume between 50 and 75 only LED2 is on
- volume between 75 and 87 only LED3 is on
- volume between 87 and 100 only LED4 is on
- volume = 100 all LEDs on

Frank

pez

Awsome, that's it, thank you, Frank!

Only when i try to start that at boot time with a service as i did with the other scripts, i get following error.
When i start the service manually it works!
Again, do you know what's wrong?

root@runeaudio(rw):~# systemctl status LED_volume
● LED_volume.service - RuneAudio LED_volume
   Loaded: loaded (/usr/lib/systemd/system/LED_volume.service; enabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Mon 2016-02-22 15:40:17 CET; 28s ago
 Main PID: 297 (code=exited, status=1/FAILURE)

Feb 22 15:40:17 runeaudio python2[297]:   File "/home/root/hw-control/LED_volume.py", line 26, in <module>
Feb 22 15:40:17 runeaudio python2[297]:     client.connect('localhost', 6600)
Feb 22 15:40:17 runeaudio python2[297]:   File "/usr/lib/python2.7/site-packages/mpd.py", line 413, in connect
Feb 22 15:40:17 runeaudio python2[297]:     self._sock = self._connect_tcp(host, port)
Feb 22 15:40:17 runeaudio python2[297]:   File "/usr/lib/python2.7/site-packages/mpd.py", line 403, in _connect_tcp
Feb 22 15:40:17 runeaudio python2[297]:     raise err
Feb 22 15:40:17 runeaudio python2[297]: socket.error: [Errno 111] Connection refused
Feb 22 15:40:17 runeaudio systemd[1]: LED_volume.service: Main process exited, code=exited, status=1/FAILURE
Feb 22 15:40:17 runeaudio systemd[1]: LED_volume.service: Unit entered failed state.
Feb 22 15:40:17 runeaudio systemd[1]: LED_volume.service: Failed with result 'exit-code'.

The service file ist this:

[Unit]
Description=RuneAudio LED_volume
After=mpd.service

[Service]

ExecStart=/home/root/hw-control/LED_volume.py

[Install]
WantedBy=multi-user.target

Cheers, Pe

hondagx35

Hi,

this is a networking issue.

You can try:

client.connect('127.0.0.1', 6600)

instead off:

client.connect('localhost', 6600)

Frank

pez

Hi Frank,
i just tried that with 127.0.0.1, runeaudio.local, IPadress but nothing helped.
I even changed the service to this but it didn't help either. Still when i start that manually, everything works fine...

[Unit]
Description=RuneAudio LED_volume
After=network.target mpd.service

[Service]

ExecStart=/home/root/hw-control/LED_volume.py

[Install]
WantedBy=multi-user.target

hondagx35

Hi pez,

please try something like this:

[Unit]
Description=RuneAudio LED_volume
After=mpd.service network.target

[Service]
ExecStart=/home/root/hw-control/LED_volume.py
ExecReload=/usr/bin/kill -HUP $MAINPID
KillMode=process
Restart=always
RestartSec=10
StartLimitInterval=30
StartLimitBurst=20

[Install]
WantedBy=multi-user.target

Frank

pez

Hey Frank, you are my personal hero.
That was the last bit of code needed to get that running.
I am currently working on the design and circuit layout for everything i need to get started to actually build that thing.
Chassis and parts for crossover are on their way, I'll start off with a mockup speakerbox just to check audio quality.
I'll post my progress, maybe it's better to move to another section of the forum, since everything seems to work fine now?
Cheers and mille gracie, pez

breizheau

Hi there.

I have just subscribed to this board and this thread is exactly what i needed !!!!!

I bought a rpi3 ( already got it and use Runeaudio with my headphones plugged on jack pkug) and the new Amp2 from Hifiberry that i hope to receive soon...

I wanted to have a on/off switch and a rotary encoder !
I have relays, momentary switches, resistors, +5 DC power supply, prototyping boards and......time !

I think i'll have work to do soon

My encoder has the momentary switch built-in.

Do you use a specific encoder or not ?

Cheers.

Olivier

pez

Hey Oliver,
in my first post i included a link to the encoder i'm using.
For the AMP2 you will need a power supply between 12 and 24V (depending on your loudspeakers): no 5V PS needed, the AMP supplies the RPi!
I'm using the included switch of the encoder to play/pause and a seperate one for I/O.
Ony the relay is controlled by the USB 5V so it switches depending on on/off state of the RPi. It controls the two functions of the I/O switch and the red/green status LED. Attached you will find my final electric scheme of all that.
pez

Attachments

: relais_simple.png (23.74 KiB) Viewed 4038 times