NEW MERIS MAKER SERIES!! ANGELO’S DIY LOOPER – PART 1
The Raspberry Pi is an inspiring device. For $40 dollars you get an incredible nerve center with which you can build an amazing array of gadgets. The same promise holds true for musicians. With a little bit of work, the Pi allows the DIY musician the ability to build a piece of gear custom suited to their needs, and is limited only by the extent of your imagination and ingenuity.
In the Meris Maker Series, we’ll first venture through and expand on the territory previously covered by the great blog Guitar Extended, who provided the inspiration for this journey. The basic concept is the same (Raspberry Pi + Pure Data = joy), but instead of building our own arduino based footcontroller, I’ll show you how to integrate an off the shelf foot controller, as well as get into some of the very useful control options and event triggering that Pure Data provides. Along the way we’ll use the foot controller to control multiple effects running on the Raspberry Pi, and the series will culminate in the modification and customization of a Raspberry Pi based Looper in the style of the Boomerang Phrase Sampler, DL4, and Ditto.
- Raspberry Pi (version B or B+)
- SD Card (click here for compatible devices)
- Griffin iMic USB audio interface
- Pi friendly keyboard and mouse (click here for compatible devices)
- HDMI Monitor and cable (or DVI monitor and a HDMI to DVI cable)
- Pi compatible USB MIDI Foot Controller (I am using the FBV Express MKII)
- Network Connection
- Ethernet cable (or buy a Pi compatible wifi dongle)
- Audio cables (The iMic is ⅛” so I use these for input and output)
- Guitar (or any other audio source: keyboard, microphone, iPhone)
- Guitar Amp (or any other convenient loudspeaker, headphones, or studio monitors)
Optional, but strongly recommended:
- USB Hub
Depending on how many USB devices you are using simultaneously, the Pi’s power supply may not provide enough current to cover the power requirements and adding a hub will solve that problem. Additionally, it is convenient to have the additional USB ports that a hub provides. This one works great for me
- Case
It’s probably a good idea to provide some protection for your Pi. The case protects the Pi’s pins from shorting and makes the Pi a lot easier to work with. I went one step further and built a little plexiglas tower for my Pi, iMic, and USB hub.
Getting Started
After amassing all of the materials, the first order of business is getting a copy of the operating system (we’ll be using Raspbian) on an SD card. The easiest path forward is buying an SD card with the OS preloaded from a vendor like Adafruit. If that’s not convenient, preparing the SD card yourself is not that difficult and here is the place to help you with that task. As I mentioned, we’ll be using Raspbian, which you can install directly, or you can install NOOBS which also allows you to select Raspbian (among other choices) as your OS on startup.
Once you have your SD card ready, it’s time to connect your keyboard, mouse, network connection, and monitor to your Pi and power up for the first time. I would hold off on connecting the iMic and foot controller for now and start by exploring the Raspberry Pi.
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More Raspberry Pi Tips
After your Pi boots up, you will be prompted for a username and password. The default user is pi with the password raspberry. After successfully logging in to your Pi, type startx to launch LXDE. LXDE provides a familiar windowing system to allow you to easily manage files and launch applications.
The Raspbian OS is a derivative of Debian, which in turn is a Linux distribution, and it is a good idea to have this list of common Linux commands handy. One of the more useful concepts is the sudo command. Sudo is used as a prefix for other commands and stands for “super user do”. It is essentially the way you tell the OS: “Yes, I really want to do this.” You will use the sudo command when shutting down the Pi, as sudo halt shuts down the Pi safely. Another common use for sudo is sudo reboot, which you can use after installations and upgrades.
One of the quirks of the Raspberry Pi is that its default keyboard localization preference is set to UK, which is fine, but chances are you are using a US keyboard and the layout is a bit different. For example, with the localization set to UK, Shift+3 will result in £ being inserted into your text instead of the # symbol. This seems really minor, but trust me it will bother you later. Go here to learn how to use raspi-config to change your keyboard layout.
In our next post, we’ll look at installing and configuring Pure Data on the Raspberry Pi.
-Angelo
(Angelo Mazzocco is a DSP Engineer/VP at Meris)