Control Jukebox with buttons / GPIO
Add buttons to your jukebox to control volume, skip tracks and more.
Before we start: One of the plus points about this projects, at least in my mind, was the fact that you don't need a soldering iron to build it. Everything is USB, plug and play, thank you, boot and go.
Many, many fellow jukebox tweakers have contacted me to push the envelope a bit further and add buttons to the jukebox. Buttons to change the volume and skip between tracks in a playlist.
So this documentation is entirely community driven, I am only editing and asking for confirmation that this works :)
Enough said, here we go.
Pin numbering on the RPi
On your RPi there are pin numbers printed on the board. In the following we are not referring to the board numbers, but the Broadcom (BCM) pin numbering for the GPIO pins. You can find more information on this issue on the pin numbering section of the GPIO Zero documentation site.
Any pin marked “GPIO” in the diagram above can be used as a pin number. A button attached to “GPIO17” would be specified in the script as pin number 17 rather than 11 (which would be the count on the board).
Fire up the soldering iron
Ok, you asked for it, roll up your sleeves and read these before you start:
You will be running wires from the RPi board to another board where the buttons will be connected. The following image is what this looks like in a successful project.
On the above image you can also see the pin numbering, in this case containing both: the RPi board numbering on the RPi3 and the Broadcom (BCM) pin numbering used for the code.
The script for the GPIO buttons we are using originally been provided by Andreas aka hailogugo. It's been modified since then and now provides
pull_up=True for all pins (not incl. shutdown). Read more in this thread why we added
Here is how to connect the buttons:
- Volume Down GPIO19 (PIN35) and GND (PIN39)
- Volume Up GPIO16 (PIN36) and GND (PIN34)
- Play/Pause/Halt (or how you call it) GPIO21 (PIN40) and GND (PIN25)
- Next GPIO26 (PIN37) and GND (PIN30)
- Previous GPIO20 (PIN38) and GND (PIN20)
- Shutdown (you need to hold button for 2 secs for shutdown) GPIO3 (PIN5) and GND (PIN6)
!!! IMPORTANT Only when using the above listed pins for wiring you will be able to power-up the Raspberry PI from firmware halt. !!!
Circuit example(s) for the button wiring
You will be using push buttons, which are essentially the same as arcade buttons, meaning: when you press them down, they are ON, when you let go, the are OFF. So skipping a track is tapping a button once, changing the volume, each tap changes it a bit.
There are a number of different ways to connect a button. The easiest one is well explained on O'Reilly's RPi site:
- Connecting a Push Switch, O'Reilly
- Watch the Connecting a Push Switch with Raspberry Pi video on YouTube
Install GPIO software
We need to run GPIO Zero, a simple interface to GPIO devices with Raspberry Pi. GPIO Zero is installed by default in Raspbian Jessie. To install see the installing chapter on their site. Better safe than sorry, so lets install the packages on our machine:
$ sudo apt-get install python3-gpiozero python-gpiozero
Note: No harm done to install both, python3 and python2. This needs trimming later on.
Make a copy of the python script for the GPIO buttons into the scripts folder. This way you are free to make changes to the script without changing your github repo.
$ sudo cp /home/pi/RPi-Jukebox-RFID/misc/sampleconfigs/gpio-buttons.py.sample /home/pi/RPi-Jukebox-RFID/scripts/gpio-buttons.py
And change the copy to be executable
$ sudo chmod +x /home/pi/RPi-Jukebox-RFID/scripts/gpio-buttons.py
Note: work in progress: the python script for the GPIO buttons will be explained when I get to it.