Setup sound I/O

Much of the documentation for setting up a USB microphone refer to Raspbian versions prior to Jessie. Since our base distribution is Jessie or newer, those do not apply. This guide follows the stackexchange, How do I configure my sound for Jasper on Raspbian Jessie?.

• Power down your pi and insert your USB webcam/microphone
• Boot the pi and connect to the cli

• Check the order in which your sound cards have been loaded, cat /proc/asound/modules. With output similar to:

  0 snd_bcm2835
  1 snd_usb_audio

• Create a file, sudo nano /etc/modprobe.d/alsa-base.conf with these lines

  # This sets the index value of the cards but doesn't reorder.
  options snd_usb_audio index=0
  options snd_bcm2835 index=1
  
  # Does the reordering.
  options snd slots=snd-usb-audio,snd-bcm2835

• Reboot the pi
• Check the sound card order, cat /proc/asound/modules
  • The order should have changed

Test sound I/O

Settings may be viewed and changed using: amixer, a command-line mixer for ALSA soundcard driver and alsamixer, a soundcard mixer for ALSA soundcard driver, with ncurses interface.

• View settings of microphone, amixer -c 0
• View settings of playback, amixer -c 1
• Adjust settings using alsamixer -c 0 and alsamixer -c 1

Recording is done with arecord, a command-line sound recorder for ALSA soundcard driver and aplay, a command-line sound player for ALSA soundcard driver.

• Record something with (stop recording with CTRL-c) arecord -D plughw:0,0 -f cd test.wav
• Play it back with aplay test.wav
• If you receive error messages or no sound record and playback occurs, please troubleshoot before continuing

Virtual Environments

A Virtual Environment is a tool to keep the dependencies required by different projects in separate places, by creating virtual Python environments for them. Jasper, a python project which helps convert voice recognition into commands, has a number of dependencies that may conflict with the OS installed Linux. A virtual environment will help greatly with this. See The Hitchhiker's Guide to Python and Virtualenv Documentation.

• Install virtualenv, sudo apt-get install virtualenv
• Some basic commands are:
  • cd my_project_folder
  • Create the virtual environment, virtualenv venv. Only needs to be created once.
  • Activate the environment, . venv/bin/activate. The prompt will change.
  • Perform tasks as usual
  • When done, deactivate the environment, deactivate

Install Jasper

• Install prerequisites, sudo apt-get install vim git-core python-dev python-pip bison libasound2-dev libportaudio-dev python-pyaudio
• Add to nano ~/.bash_profile export LD_LIBRARY_PATH="/usr/local/lib" source .bashrc
• Add to nano ~/.bashrc LD_LIBRARY_PATH="/usr/local/lib" export LD_LIBRARY_PATH PATH=$PATH:/usr/local/lib/ export PAT
• Clone Jasper, git clone https://github.com/jasperproject/jasper-client.git jasper
• cd jasper
• Create virtualenv, virtualenv venv
• Activate the environment, . venv/bin/activate
• Install Jasper requirements, pip install -r client/requirements.txt. This might take a while to compile

Install PocketSphinx and requirements

This follows the Jasper guide closely.

• Install PocketSphinx, sudo apt-get install pocketsphinx
• Installing CMUCLMTK
  • sudo apt-get install subversion autoconf libtool automake gfortran g++
  • svn co https://svn.code.sf.net/p/cmusphinx/code/trunk/cmuclmtk/
  • cd cmuclmtk/
  • ./autogen.sh && make, Check for errors prior to next step
  • sudo make install
  • cd ~
• Installing OpenFST, Phonetisaurus, m2m-aligner and MITLM
  • sudo su -c "echo 'deb http://ftp.debian.org/debian experimental main contrib non-free' > /etc/apt/sources.list.d/experimental.list"
  • sudo apt-get update
  • sudo apt-get -t experimental install phonetisaurus m2m-aligner mitlm libfst-tools
• Building the Phonetisaurus FST model
  • wget https://www.dropbox.com/s/kfht75czdwucni1/g014b2b.tgz
  • tar -xvf g014b2b.tgz
  • cd g014b2b
  • ./compile-fst.sh
  • cd ..
  • mv ~/g014b2b ~/phonetisaurus