The Indian Sonic Research Organisation | Main / DIYEFFECTSPROCESSOR

D.I.Y EFFECTS PROCESSOR

Setting up and getting started with Raspberry Pi

1. Insert an SD card with Raspbian installed in its respective slot.
2. Connect a mouse and a keyboard to one of the USB ports.
3. Connect the Raspberry Pi 3 to a PC monitor via an HDMI cable. Use a VGA to HDMI converter if necessary.
4. Connect a LAN cable to its respective slot or use a USB Wifi adapter to connect to a Wifi network.
5. Turn on the Raspberry Pi 3 by connecting a charger with microUSB pin to the respective slot.

Now you essentially have a desktop with the Raspberry Pi being the CPU

Installing Csound

1. Go to the Terminal or press Alt+Ctrl+T.
2. Install Csound by typing sudo apt-get install csound.
3. Install ALSA (Advanced Linux Sound Architecture) by typing sudo apt-get install alsa-utils.
4. Get updates by typing sudo apt-get update.

Configuring the SoundCard

Follow the steps here - http://www.horus.com/~hias/cirrus-driver.html. But the system does not allow the selection of the RPI-Cirrus soundcard from the audio settings options on the desktop. Had to follow this - https://raspberrypi.stackexchange.com/questions/19705/usb-card-as-my-default-audio-device to discover the command to play with the soundcard.

$ aplay loop.wav -D sysdefault:CARD=0

Following the configuration steps above, the RPI-Cirrus soundcard is selected as card 0. But the system still plays to the inbuilt sound card.

Tried setting

`#dtparam=audio=on`

in /boot/config.txt

to disable the default audio card. But the desktop keeps jumping on bootup and doesn't draw any of the menus. The system becomes unusable using the desktop GUI. Had to ssh to it, to uncomment the dtparam line and reboot.

Making RaspberryPi Linux Lean

This section deals with trying to squeeze as much performance as possible out of the Raspberry Pi, to reduce audio latency. We followed a lot of the steps detailed here - https://wiki.linuxaudio.org/wiki/raspberrypi although that page was written for running Jack on Raspberry Pi. And we currently haven't configured that. Perhaps that is the next step in trying to reduce latency, is to switch from ALSA to using Jack.

Step 1 Turning Off GUI

Turning off Raspberry Pi GUI. This was done using raspi-config.

    $ sudo raspi-config

Select the 3rd option 'Enable Boot to Desktop/Scratch'. Then choose boot option 'Console Text console, requiring login(default)'.

Step 2 Overclocking

In raspi-config now select the 7th option 'Overclock'. Click Ok for the warning and select an option to overclock. We have only tested with 'Modest' setting for overclock and the system appears to work fine.

Step 3 Turn Off Unnessary Services

From here - https://wiki.linuxaudio.org/wiki/raspberrypi . We ran the following commands in the console:

    $ sudo service ntp stop
    $ sudo service triggerhappy stop
    $ sudo service dbus stop
    $ sudo killall console-kit-daemon
    $ sudo killall polkitd

Important

The changes to raspi-config are permanent. If you have problems with overclocking on the system or want to get your GUI back. You must login to the Raspberry Pi (using ssh or connected to the main terminal) and run raspi-config again.

To enable the GUI

    $ sudo raspi-config

Select the 3rd option 'Enable Boot to Desktop/Scratch' and then select the 2nd option in the next menu.

Similarly you can select option #7 Overclock and either disable it completely or try lower settings.