Software Lab NMC

From CCRMA Wiki

(Difference between revisions)
Jump to: navigation, search
(Getting Comfortable With Satellite CCRMA)
 
(23 intermediate revisions not shown)
Line 1: Line 1:
<font size=5>Lab 1: Making Music with Pd in Satellite CCRMA</font><br>
<font size=5>Lab 1: Making Music with Pd in Satellite CCRMA</font><br>
-
Lab write-up due on Tuesday, July 12 at 9AM
+
Lab write-up due on Tuesday at 10AM
-
(For the lab write-up, answer all the questions asked below, and include pd patches of your solutions.)
+
Most instructions by Edgar Berdahl, and lab patches for musical interaction description by Matt Wright and possibly others
-
<!--  After completing the lab, create a text-file answering questions from the lab, describing what you authored/modified and anything we need to know to test your patch. Put this file in your lab1 folder. Then zip up your lab1 folder and email it to music250a-aut1011-staff@lists.stanford.edu. Please make the subject of the email "Lab 1 - yourlastname" so that it gets sorted properly upon receipt.   -->
+
For this lab you need your [http://ccrma.stanford.edu/~eberdahl/Satellite Satellite CCRMA kit], a computer to program it, and some headphones with a mini 1/8" stereo jack.
-
For this lab you need your [[http://ccrma.stanford.edu/~eberdahl/Satellite Satellite CCRMA kit]], a computer to program it, and some headphones with a mini 1/8" stereo jack. During this lab, you will start to use your kit.
 
Line 15: Line 14:
  - One Ethernet cable for external communication
  - One Ethernet cable for external communication
  - Arduino Nano
  - Arduino Nano
-
  - One GT Max adjustable-length USB cable
+
  - One adjustable-length USB cable
-
If you are missing something, please go get it before assembling your kit. Use the USB cable to connect the Arduino to the Beagle Board. Make sure you plug the micro SDHC memory card fully into its seat so that it looks as shown inside the red box:
+
If you are missing something, please go get it before assembling your kit. Make sure you plug the micro SDHC memory card fully into its seat so that it looks as shown inside the red box:
[[Image:Kitblank.jpg]]
[[Image:Kitblank.jpg]]
 +
 +
 +
== Powering Up For The First Time ==
== Powering Up For The First Time ==
Line 25: Line 27:
[[Image:Kitplugged.jpg]]
[[Image:Kitplugged.jpg]]
 +
 +
 +
== Connect To Satellite CCRMA ==
== Connect To Satellite CCRMA ==
-
In order to see what your Satellite CCRMA kit is doing and program it, you need to log in to it. To do so, follow [https://ccrma.stanford.edu/wiki/CCRMA_Satellite_How_To_Connect these instructions].
+
In order to see what your Satellite CCRMA kit is doing and program it, you need to log in to it. To do so, follow [https://ccrma.stanford.edu/wiki/CCRMA_Satellite_How_To_Connect_RevC these instructions].
After you login, you will see the prompt ''ccrma@satellite:~$''  This means that you are logged into a computer named "satellite" as the user "ccrma", and you are currently in the directory ~, which is the shortcut for your home directory.
After you login, you will see the prompt ''ccrma@satellite:~$''  This means that you are logged into a computer named "satellite" as the user "ccrma", and you are currently in the directory ~, which is the shortcut for your home directory.
-
== Avoid Powering Down the Board Without Halting it First! ==
 
-
Would you take the battery out of your laptop and unplug its power adaptor without shutting down? ''I don't think so!'' The same goes for Satellite CCRMA, at least when you can avoid it, because it is a small computer running linux.
 
-
Now we will test the halt procedure. Run the halt command as superuser by typing ''sudo halt'' at the Satellite CCRMA prompt. Then you will again have to type in the password ''temppwd'' in order to have the privilege to run this command. The SSH connection will be closed, but it will still be 20 seconds or so before Satellite CCRMA has completely shut down. (Note: The command ''sudo reboot'' would instead have caused Satellite CCRMA to reboot itself.)
 
-
Wait an extra entire minute to ensure that Satellite CCRMA is shut down. However, it will not power itself off. To do this, you need to disconnect the 5V power adaptor from the hub.
 
-
== Getting Comfortable With Satellite CCRMA ==
+
== Avoid Powering Down the Board Without Halting it First! ==
-
Turn on Satellite CCRMA again using the same procedure as before where you plug the power into the USB hub. After about 30 seconds, the board should be booted up again, so you can log in again by running the command
+
Would you take the battery out of your laptop and unplug its power adaptor without shutting down? ''I don't think so!'' The same goes for Satellite CCRMA, at least when you can avoid it, because it is a small computer running linux.
-
''ssh -X ccrma@192.168.1.105''
+
Now we will test the halt procedure. Run the halt command as superuser by typing ''sudo halt'' at the Satellite CCRMA prompt. Then you will again have to type in the password ''temppwd'' in order to have the privilege to run this command. Wait until about 15 seconds after you see the message "Connection to 192.168.105.106 closed by remote host," and then disconnect the 5V power adaptor from the Beagle Board.
-
<!-- If you list the device directory, you can see which devices are attached to linux. Type
 
-
''ls /dev''
 
-
to get an idea. Wow, there are so many! To list the devices with serial interfaces type
 
-
''ls /dev/tty*''
+
== Getting Comfortable With Satellite CCRMA ==
 +
* Turn on Satellite CCRMA again using the same procedure as before where you plug the power into the Beagle Board. After about 30 seconds, the board should be booted up again, so you can log in again by running the command
-
Once of these devices should be ''/dev/ttyUSB0'' for the Arduino Nano. If you do not see this one, then try rebooting using ''sudo reboot'' to see if that fixes this problem. (If you reboot, this will take about 45 seconds, and you will have to login again using ''ssh''. If that doesn't work, come talk to us. If you are a linux pro, you can try to debug the problem yourself by typing ''dmesg'' and looking at the result.)  -->
+
''ssh -XY ccrma@192.168.105.106''
-
Run the command ''pwd'' to find out the current directory. You will find that you are in the ''ccrma'' subdirectory of the directory ''/home''.
+
* Run the command ''pwd'' to find out the current directory. You will find that you are in the ''ccrma'' subdirectory of the directory ''/home''.
-
Type the ''ls'' command to see what is in the current directory. The blue items are subdirectories of the current directory. You can change directories using the ''cd'' command. For instance, to change into the ''pd_lecture'' subdirectory, you should run the command
+
* Type the ''ls'' command to see what is in the current directory. The blue items are subdirectories of the current directory. You can change directories using the ''cd'' command. For instance, to change into the ''pd_lecture'' subdirectory, you should run the command
''cd pd_lecture''
''cd pd_lecture''
-
Now again type ''pwd'' to make sure that you understand where you are! Run the ''ls'' command to see what files are in here.
+
* Now again type ''pwd'' to make sure that you understand where you are! Run the ''ls'' command to see what files are in here.
-
 
+
-
 
+
-
Find out if you have successfully connected Satellite CCRMA to the Internet by running the command
+
* Find out if you have successfully connected Satellite CCRMA to the Internet by running the command
''ping yahoo.com''
''ping yahoo.com''
-
If you get responses that take about 100 ms to 200 ms, then everything is in order.
+
* If you get responses that take about 100 ms to 200 ms, then your settings are correct.
-
== Starting Audio And Pd ==
 
-
First we need to start up the audio connection kit. It's easiest to do so using the graphical interface, so execute the command
 
-
''qjackctl &''
 
-
The ampersand (&) is there to indicate that even though you are opening a new window, you should still be able to keep typing at the old terminal. There might be some strange error message windows, but just close these to get back to the main JACK Audio Connection Kit. To start audio, click on the ''Start'' button.
+
== Starting Audio And Pd ==
 +
 
 +
* First we need to start up the audio connection kit. It's easiest to do so using the graphical interface, so execute the command '''start-jackd'''
-
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 labeled AUDIO OUT on the Beagle Board. '''Be very careful when plugging the headphones in and not to pull too hard on the headphone cable! Unfortunately it comes off of the board very easily, and then you will have to buy a new board for $150!!!'''
+
* 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 labeled AUDIO OUT on the Beagle Board. '''Be very careful when plugging the headphones in and not to pull too hard on the headphone cable! Unfortunately it comes off of the board very easily, that is you can break the board this way!!!'''
-
Start pd now with the following command, where again we include &:
+
* Start pd now with the following command, where again we include &:
''pd &''
''pd &''
-
Choose ''Open'' from the ''File'' menu and select the patch ''4_algorithmic_music.pd''. In the main ''pd-extended'' window, click on the ''compute audio'' button. Then go back to the patch, move the speed and width sliders slightly to the right, and bring up the volume. You should now hear some sound in your headphones. Play around with the parameters to see what new sounds you can discover.
+
* Choose ''Open'' from the ''File'' menu and select the patch ''4_algorithmic_music.pd''. In the main ''pd-extended'' window, click on the ''compute audio'' button. Then go back to the patch, move the speed and width sliders slightly to the right, and bring up the volume. You should now hear some sound in your headphones. Play around with the parameters to see what new sounds you can discover.
Troubleshooting: 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.
Troubleshooting: 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.
-
== Optional: Programming Linux ==
 
-
'''We don't actually expect you to do anything here, we are just providing some more information that is maybe helpful for you linux gurus.''' Since ccrma@satellite runs ubuntu linux on an OMAP chip, many standard software packages have been compiled for it. This is why we were easily able to install software such as Jack, [http://audacity.sourceforge.net/ Audacity], [http://chuck.cs.princeton.edu/ ChucK], [http://faust.grame.fr/ Faust], [https://ccrma.stanford.edu/groups/soundwire/software/jacktrip/ Jacktrip], and the Arduino software.
 
-
If you are lucky, you can install your favorite software using the ''apt-get'' utility. To get a list of packages available on the OMAP's ARM architecture, type
 
-
''sudo apt-cache pkgnames''
 
-
You will notice that this list is way too long to look at. You can pipe it to the text file using the command
+
== The Patches Are Already On The Board==
-
''sudo apt-cache pkgnames > packages.txt''
+
*  You can find the main patch at /home/ccrma/pd/labs-Music-250a-2011/lab1/myinstrument.pd
-
and then look at it using ''emacs packages.txt'', or you search for a particular package, such as
 
-
''sudo apt-cache pkgnames | grep emacs''.
 
-
Or, you can compile linux software yourself on the Beagleboard. The gcc, g++ tools etc. are already installed.
 
-
Type the ''df'' command. You can see that there is not a whole lot more than 1GB available on the SD card, so you should only install software if you decide that you need it.
+
== Play Around With the Patches ==
 +
* Go back to ''pd'' and open the patch labeled ''myinstrument.pd'' inside ''software_lab_pd''. Make sure that ''compute audio'' is set to on and ''qjackctl'' is still open and running. Play around with the patch. You should be able to exhaust its musical potential in a matter of minutes; reflect on its strengths and limitations.
 +
* Also try to understand how it works as a piece of software. (But please don't get hung up on the arcana - as always, if you get stuck, ask for help rather than waste time.)
-
== Halt Your Board Properly When Finished! ==
 
-
'''Remember to shut down your board when you are done before powering it off!''' (Of course as Spencer pointed out, if you are operating ''truly'' autonomously, of course you cannot login and run the halt command. Nevertheless, if it is not too inconvenient please try to shut down properly if you can. If you do not, then you may find that your SD memory card becomes corrupted.) As described above, you can do this by executing the command ''sudo halt'' and then waiting 30 seconds before disconnecting the power cables.
 
-
==Install==
+
==Documentation==
-
If you will use your own laptop, install [http://sourceforge.net/projects/pure-data/files/pd-extended/ Pd extended v0.41.4].  Make sure that you install the ''extended'' version so that you have all of the objects that you need.
+
-
If you're running Pd using a desktop machine on the CCRMA network, make sure that you followed the instructions [http://ccrma.stanford.edu/courses/250a/lectures/pd/ in this lecture] for configuring Pd.
+
* Right-click or option-click on any object to get a contextual menu including "help," which opens that object's help patch. (If you are using a Mac and don't have a right mouse button, then go to the ''X11'' pull-down menu, select ''Preferences'', and make sure that ''Emulate three button mouse'' is checked in the ''Input'' pane. Now, you should be able to right-click by clicking while holding down the Command key.)
-
== Download the Lab Patches to Your Home Directory==
+
* Right-click on a blank portion of a Pd patch. Now when you select "help" you get a list of Pd's built-in objects, arranged by category.
-
* Download the patches into your 250a directory and uncompress the archive: [http://ccrma.stanford.edu/courses/250a/workshop/software_lab_pd.zip software_lab_pd.zip]
+
* In the upper right hand corner of each Pd window is a "help" menu. This accesses the Pd tutorials as well as some online reference documentation.
-
== Play Around With the Patches ==
 
-
* Open the patch labeled myinstrument. Play around with this patch. You should be able to exhaust its musical potential in a matter of minutes; reflect on its strengths and limitations.
 
-
* Also try to understand how it works as a piece of software. (But please don't get hung up on the arcana - as always, if you get stuck, ask for help rather than waste time.)
 
-
 
-
==Documentation==
 
-
 
-
* Right-click or option-click on any object to get a contextual menu including "help," which opens that object's help patch.
 
-
 
-
** Right-click on a blank portion of a Pd patch. Now when you select "help" you get a list of Pd's built-in objects, arranged by category.
 
-
** In the upper right hand corner of each Pd window is a "help" menu. This accesses the Pd tutorials as well as some online reference documentation.
 
==Short questions==
==Short questions==
Line 142: Line 120:
Make a patch that shows how to connect some objects together to calculate the function ''1-x'' where ''x'' is an input number.  Save the patch in a file called ''OneMinus''.
Make a patch that shows how to connect some objects together to calculate the function ''1-x'' where ''x'' is an input number.  Save the patch in a file called ''OneMinus''.
-
==Key Repeat==
+
 
-
* What happens when you hold down a key? The behavior may depend on what operating system you are running.
+
 
-
* Is the behavior desirable on your system?  What operating system are you running?
+
== Design a different musical interaction ==
== Design a different musical interaction ==
Line 169: Line 146:
* Use a totally different form of sound synthesis, such as FM, granular, or physical modeling.
* Use a totally different form of sound synthesis, such as FM, granular, or physical modeling.
-
We recommend that you pick one or a small number of these and work on it in depth, iterating on both the program/test/debug cycle as well as the design/implement/play cycle to craft something that has actual musical potential or is at least more fun to play. If you have an existing idea for your class project, you could use this lab to start thinking about implementing some of the modes and mappings. By all means, if you're inspired to try something else, go for it. If you'd rather spend today getting more of a broad sense of Pd's capabilities, feel free to work on many of these suggestions.
+
We recommend that you pick '''only one or a small number''' of these and work on it in depth, iterating on both the program/test/debug cycle as well as the design/implement/play cycle to craft something that has actual musical potential or is at least more fun to play. If you have an existing idea for your class project, you could use this lab to start thinking about implementing some of the modes and mappings. By all means, if you're inspired to try something else, go for it. If you'd rather spend today getting more of a broad sense of Pd's capabilities, feel free to work on many of these suggestions.
 +
 
 +
 
 +
 
== The Community ==
== The Community ==
-
There is a large, dedicated, and very generous community of Pd users on the Internet. Do some web searching (e.g., with a search engine, or else starting from some more specific resources) and look for interesting externals and/or patches. Download, install, and play with at least one. Can you incorporate it into what you programmed in the previous part?
+
There is a large, dedicated, and very generous community of Pd users on the Internet. Do some web searching (e.g., with a search engine, or else starting from some more specific resources) and look for interesting externals and/or patches. '''Optional:''' Download, install, and play with at least one. Can you incorporate it into what you programmed in the previous part?
For more help in finding resources, don't forget to look on the [[PID Links]] page.
For more help in finding resources, don't forget to look on the [[PID Links]] page.
-
<center>[[NMC 2011]]</center>
+
 
-
[[Category:NMC_2011]][[Category:NMC]]
+
 
 +
 
 +
== Appendix: Troubleshooting ==
 +
Tips:
 +
* Type <tt>dmesg</tt> to see if there are any relevant messages that look like error messages.
 +
* Check if the Jack audio server has crashed. If so, then restart it.
 +
 
 +
Solutions:
 +
* If you are running out of space on the SD card, you can free up some space by deleting items in <tt>/usr/src</tt>. For instance, all of the files needed for building Pure Data Extended are rather large.
 +
* If you are unable to access the internet from Satellite CCRMA, and you are not at CCRMA, then you may need to change the DNS nameserver specified in <tt>/etc/resolv.conf</tt> You could do this using the <tt>set-DNS-server</tt> command.
 +
 
 +
 
 +
 
 +
 
 +
== Optional: Programming Linux ==
 +
'''We don't actually expect you to do anything here, we are just providing some more information that is maybe helpful for you linux gurus.''' Since ccrma@satellite runs ubuntu linux on an OMAP chip, many standard software packages have been compiled for it. This is why we were easily able to install software such as Jack, [http://audacity.sourceforge.net/ Audacity], [http://chuck.cs.princeton.edu/ ChucK], [http://faust.grame.fr/ Faust], [https://ccrma.stanford.edu/groups/soundwire/software/jacktrip/ Jacktrip], and the Arduino software.
 +
 
 +
If you are lucky, you can install your favorite software using the ''apt-get'' utility. To get a list of packages available on the OMAP's ARM architecture, type
 +
 
 +
''sudo apt-cache pkgnames''
 +
 
 +
You will notice that this list is way too long to look at. You can pipe it to the text file using the command
 +
 
 +
''sudo apt-cache pkgnames > packages.txt''
 +
 
 +
and then look at it using ''emacs packages.txt'', or you search for a particular package, such as
 +
 
 +
''sudo apt-cache pkgnames | grep emacs''.
 +
 
 +
Or, you can compile linux software yourself on the Beagleboard. The gcc, g++ tools etc. are already installed.
 +
 
 +
Type the ''df'' command. You can see that there is not a whole lot more than 1GB available on the SD card, so you should only install software if you decide that you need it.
 +
 
 +
 
 +
 
 +
 
 +
== Halt Your Board Properly When Finished! ==
 +
'''Remember to shut down your board when you are done before powering it off!''' (Of course, if you are operating ''truly'' autonomously, of course you cannot login and run the halt command. Nevertheless, if it is not too inconvenient please try to shut down properly if you can. If you do not, then you may find that your memory card becomes corrupted.)
 +
 
 +
 
 +
 
 +
 
 +
== Copying Files To and From Your Kit ==
 +
* Alternatively, if you would like to use software with a nice GUI for copying files back and forth from your kit, you can install additional special software on your laptop.  For Windows, install [https://itservices.stanford.edu/service/ess/pc/securefx Secure FX], or for Mac OS X, install [https://itservices.stanford.edu/service/ess/mac/fetch Fetch].  These programs actually use scp, but they hide the details of the pathnames from you.
 +
 
 +
 
 +
 
 +
 
 +
== More Pd resources ==
 +
* Here are some lists of pd objects that you can use to discover new object names: [http://protman.com/content/list-puredata-objects-and-extended-objects http://protman.com/content/list-puredata-objects-and-extended-objects] [http://www.umatic.nl/workshop/objects.txt http://www.umatic.nl/workshop/objects.txt]
 +
 
 +
 
 +
 
 +
<center>[[PID 2010]]</center>
 +
[[Category:PID_2010]][[Category:PID]]

Current revision as of 06:47, 11 June 2012

Lab 1: Making Music with Pd in Satellite CCRMA
Lab write-up due on Tuesday at 10AM

Most instructions by Edgar Berdahl, and lab patches for musical interaction description by Matt Wright and possibly others

For this lab you need your Satellite CCRMA kit, a computer to program it, and some headphones with a mini 1/8" stereo jack.


Contents

The Satellite CCRMA Setup

Included in your kit you should have

- Satellite CCRMA Hardware (Beagle Board + microSDHC memory card + Arduino Nano + solderless breadboard)
- One 5V power adaptor to plug into the Beagle Board
- One Ethernet cable for external communication
- Arduino Nano
- One adjustable-length USB cable

If you are missing something, please go get it before assembling your kit. Make sure you plug the micro SDHC memory card fully into its seat so that it looks as shown inside the red box:

Image:Kitblank.jpg



Powering Up For The First Time

Plug the Ethernet port of the Satellite CCRMA into your laptop. Then plug in the 5V power supply into the Beagle as shown below. You should see some lights turn on, flickering every now and then. This means that Satellite CCRMA is booting up.

Image:Kitplugged.jpg



Connect To Satellite CCRMA

In order to see what your Satellite CCRMA kit is doing and program it, you need to log in to it. To do so, follow these instructions.

After you login, you will see the prompt ccrma@satellite:~$ This means that you are logged into a computer named "satellite" as the user "ccrma", and you are currently in the directory ~, which is the shortcut for your home directory.



Avoid Powering Down the Board Without Halting it First!

Would you take the battery out of your laptop and unplug its power adaptor without shutting down? I don't think so! The same goes for Satellite CCRMA, at least when you can avoid it, because it is a small computer running linux.

Now we will test the halt procedure. Run the halt command as superuser by typing sudo halt at the Satellite CCRMA prompt. Then you will again have to type in the password temppwd in order to have the privilege to run this command. Wait until about 15 seconds after you see the message "Connection to 192.168.105.106 closed by remote host," and then disconnect the 5V power adaptor from the Beagle Board.



Getting Comfortable With Satellite CCRMA

  • Turn on Satellite CCRMA again using the same procedure as before where you plug the power into the Beagle Board. After about 30 seconds, the board should be booted up again, so you can log in again by running the command

ssh -XY ccrma@192.168.105.106

  • Run the command pwd to find out the current directory. You will find that you are in the ccrma subdirectory of the directory /home.
  • Type the ls command to see what is in the current directory. The blue items are subdirectories of the current directory. You can change directories using the cd command. For instance, to change into the pd_lecture subdirectory, you should run the command

cd pd_lecture

  • Now again type pwd to make sure that you understand where you are! Run the ls command to see what files are in here.
  • Find out if you have successfully connected Satellite CCRMA to the Internet by running the command

ping yahoo.com

  • If you get responses that take about 100 ms to 200 ms, then your settings are correct.



Starting Audio And Pd

  • First we need to start up the audio connection kit. It's easiest to do so using the graphical interface, so execute the command start-jackd
  • 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 labeled AUDIO OUT on the Beagle Board. Be very careful when plugging the headphones in and not to pull too hard on the headphone cable! Unfortunately it comes off of the board very easily, that is you can break the board this way!!!
  • Start pd now with the following command, where again we include &:

pd &

  • Choose Open from the File menu and select the patch 4_algorithmic_music.pd. In the main pd-extended window, click on the compute audio button. Then go back to the patch, move the speed and width sliders slightly to the right, and bring up the volume. You should now hear some sound in your headphones. Play around with the parameters to see what new sounds you can discover.

Troubleshooting: 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.



The Patches Are Already On The Board

  • You can find the main patch at /home/ccrma/pd/labs-Music-250a-2011/lab1/myinstrument.pd



Play Around With the Patches

  • Go back to pd and open the patch labeled myinstrument.pd inside software_lab_pd. Make sure that compute audio is set to on and qjackctl is still open and running. Play around with the patch. You should be able to exhaust its musical potential in a matter of minutes; reflect on its strengths and limitations.
  • Also try to understand how it works as a piece of software. (But please don't get hung up on the arcana - as always, if you get stuck, ask for help rather than waste time.)



Documentation

  • Right-click or option-click on any object to get a contextual menu including "help," which opens that object's help patch. (If you are using a Mac and don't have a right mouse button, then go to the X11 pull-down menu, select Preferences, and make sure that Emulate three button mouse is checked in the Input pane. Now, you should be able to right-click by clicking while holding down the Command key.)
  • Right-click on a blank portion of a Pd patch. Now when you select "help" you get a list of Pd's built-in objects, arranged by category.
  • In the upper right hand corner of each Pd window is a "help" menu. This accesses the Pd tutorials as well as some online reference documentation.



Short questions

Why is the following patch a bad idea?

Image:badidea.gif

Make a patch that shows how to connect some objects together to calculate the function 1-x where x is an input number. Save the patch in a file called OneMinus.



Design a different musical interaction

Here are some ideas of changes that might make the patch more interesting:

  • Involve more QWERTY keys
  • Involve the mouse (see the [MouseState] object)
  • Load in a larger collection of samples.
    • Implement a mechanism to switch among banks of samples
  • Multiple gestures to one result: design a way for the parameters of each triggered note to depend on multiple key presses. For example, maybe only the space bar triggers notes, and all the other keys determine parameters of notes.
    • Make your patch automatically generate a bassline as a function of the key presses
    • Set multiple parameters modally, as volume works in the sample patch
    • Use chording: keep track of all the keys that are currently pressed, and use only that information to set the parameters for each note.
  • One gesture to multiple results
    • Use the "metro" object to trigger a steady stream of notes. Now you have two new parameters: repetition rate, and whether the metro is on or off.
    • Use the "counter" object to step through a cycle (of samples, parameter settings, etc.)
    • You could combine "metro" and "counter" to build a rudimentary sequencer that can step through a rhythmic pattern
    • Invent a mechanism to record short sequences of keypresses and play them back in time.
  • Incorporate looping or other interactive controls over the soundfile playback
  • Use Pd's "spigot" object to route control information to different parts of your patch at different times
  • Use some additional signal processing such as a filter, delay line, reverb, tremolo, etc. This gives you more parameters to control.
  • Polyphony: make it so the patch can play multiple samples at the same time. (Hint: put multiple copies of "play-sample" in your patch)
  • Use a totally different form of sound synthesis, such as FM, granular, or physical modeling.

We recommend that you pick only one or a small number of these and work on it in depth, iterating on both the program/test/debug cycle as well as the design/implement/play cycle to craft something that has actual musical potential or is at least more fun to play. If you have an existing idea for your class project, you could use this lab to start thinking about implementing some of the modes and mappings. By all means, if you're inspired to try something else, go for it. If you'd rather spend today getting more of a broad sense of Pd's capabilities, feel free to work on many of these suggestions.



The Community

There is a large, dedicated, and very generous community of Pd users on the Internet. Do some web searching (e.g., with a search engine, or else starting from some more specific resources) and look for interesting externals and/or patches. Optional: Download, install, and play with at least one. Can you incorporate it into what you programmed in the previous part?

For more help in finding resources, don't forget to look on the PID Links page.



Appendix: Troubleshooting

Tips:

  • Type dmesg to see if there are any relevant messages that look like error messages.
  • Check if the Jack audio server has crashed. If so, then restart it.

Solutions:

  • If you are running out of space on the SD card, you can free up some space by deleting items in /usr/src. For instance, all of the files needed for building Pure Data Extended are rather large.
  • If you are unable to access the internet from Satellite CCRMA, and you are not at CCRMA, then you may need to change the DNS nameserver specified in /etc/resolv.conf You could do this using the set-DNS-server command.



Optional: Programming Linux

We don't actually expect you to do anything here, we are just providing some more information that is maybe helpful for you linux gurus. Since ccrma@satellite runs ubuntu linux on an OMAP chip, many standard software packages have been compiled for it. This is why we were easily able to install software such as Jack, Audacity, ChucK, Faust, Jacktrip, and the Arduino software.

If you are lucky, you can install your favorite software using the apt-get utility. To get a list of packages available on the OMAP's ARM architecture, type

sudo apt-cache pkgnames

You will notice that this list is way too long to look at. You can pipe it to the text file using the command

sudo apt-cache pkgnames > packages.txt

and then look at it using emacs packages.txt, or you search for a particular package, such as

sudo apt-cache pkgnames | grep emacs.

Or, you can compile linux software yourself on the Beagleboard. The gcc, g++ tools etc. are already installed.

Type the df command. You can see that there is not a whole lot more than 1GB available on the SD card, so you should only install software if you decide that you need it.



Halt Your Board Properly When Finished!

Remember to shut down your board when you are done before powering it off! (Of course, if you are operating truly autonomously, of course you cannot login and run the halt command. Nevertheless, if it is not too inconvenient please try to shut down properly if you can. If you do not, then you may find that your memory card becomes corrupted.)



Copying Files To and From Your Kit

  • Alternatively, if you would like to use software with a nice GUI for copying files back and forth from your kit, you can install additional special software on your laptop. For Windows, install Secure FX, or for Mac OS X, install Fetch. These programs actually use scp, but they hide the details of the pathnames from you.



More Pd resources


PID 2010
Personal tools