7745 Lab 2

From CCRMA Wiki
Revision as of 13:38, 29 January 2014 by Eberdahl (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

Lab 2: Sound Synthesis in Pure Data using Satellite CCRMA
by Edgar Berdahl, Jan 2014

Powering Up For The First Time

Plug the Ethernet port of the Raspberry Pi into your laptop. Then use the USB micro cable to power up the Raspberry Pi. (If you have a USB power supply, you could use it to power the Raspberry Pi, or if not you can try using your laptop's USB connector to power the Rasberry Pi.) You should see some lights turn on, flickering every now and then. This means that the Raspberry Pi is booting up.

Connect To Satellite CCRMA

  • Connect your kit to your laptop using an Ethernet cable and power up your kit. If you have any difficulties, you can refer back to lab 1.
  • Open up the terminal program and connect to your kit using the command

ssh -XY ccrma@

Starting Audio And Pd

  • In order to be able to hear audio, you will need to plug a pair of ear buds, headphones, or loudspeakers into the 1/8" (2.54mm) jack on the Raspberry Pi (often it is yellow).
  • A default pd patch starts running automatically when your kit finishes booting up. To stop the default pd patch from running, execute the command


  • Start pd now with the following command

pd &

This time the graphical user interface (GUI) for pd should also start.

  • To start audio, click on the Compute audio checkbox.
  • If you want to test audio, go to the media pull-down menu and choose Test Audio and MIDI. If you still do not here any sound, then probably you missed one of the steps so far. If you look at the messages in the main pd window, you might find a clue.
  • Once you have audio working, close the test audio and MIDI window.

Help With Learning Pd

  • Try out the example patches in ~/pd/7745/lab2/separate-examples
  • Look at the tutorial patches in ~/pd/7745/lab2/pd_lecture_part_2'

Lab Assignment

Please complete either of the following assignment patches and submit it to get credit for this lab:

  • Choose Open from the File menu and select the patch lab2-survey.pd within your ~/pd/7745/lab2 directory. In this version of the assignment, you will complete some survey exercises to help you learn about more basic sound synthesis techniques such as additive synthesis, subtractive synthesis, and frequency modulation (FM) synthesis.


  • Choose Open from the File menu and select the patch lab2-granular.pd within your ~/pd/7745/lab2 directory. In this version of the assignment, you will finish building a granular synthesizer in pd.

If you can't find the patches, you can download them to your laptop using from this link. Complete the exercises in this patch and then submit the result on Moodle. See Appendix B from lab 1 for copying files onto and off of your kit, or you can take snapshots of your computer screen and email these if that's easier. (Or, you could even print out the patch and submit the paper printout--perhaps the only way to do that is using screen snapshots also.)

Halt Your Board Properly When Finished!

  • Remember to shut down your board using

sudo halt

when you are done before powering it off!

PID 2013