Trigger signal to MaxMSP

    Dec 11 2010 | 6:46 pm
    I am currently a student in interactive multimedia program at university and we are working at this moment on our final bachelor project.
    As final project, we want to do a live show with a visual presentation (3d movie sequences) and we want to use a performer (storyteller) to interact with the visual and audio presentation by using any kinds of triggers (pressure, wind, thermal, etc).
    Our audio team is working hard on this at this moment and they have a problem. At this moment, they can import an audio file to MaxMSP and can interact with it. We can also do the same with visual sequences. The problem come when we try to use triggers. They told me that they don't know how to transform the trigger signal (pressure trigger at this moment) so that MaxMSP can understand it.
    So, from what I understood, the trigger is emitting an electric signal and they want to transform this signal into some kind of audio format that MaxMSP could understand (read).
    Is there anyone that could help us on this ? Also, keep in mind than we are not really triggers or MaxMSP experts. Thank you!
    Have a nice day!
    P.S. By the way, sorry for my bad english, it is not my native language.

    • Dec 11 2010 | 7:12 pm
      Microphones also emit electrical signals - these are converted to numbers that MSP can use within the computer by the analog-to-digital converters in your audio interface.
      Once you have successfully scaled the electrical signal emitted by your trigger device to an input range that will work with your analog-to-digital converter, working with the resulting signal will be just like working with the signal from a microphone. It is highly likely that you can work at a vastly lower sampling rate than we use for microphones, however! (And you may be using a special AD converter that can accommodate many lo-fi inputs?? Here you have many choices...)
      Detecting a trigger will likely be similar to looking for a sudden transient-rich noise in an audio signal - there are externals that can do this, or you can write a patch for it.
    • Dec 11 2010 | 8:07 pm
      "trigger is emitting an electric signal"
      we need more information than this about the trigger. anything you know: what kind of electric signal? what kind of interface/cable(usb? analog-to-digitally converted audio or midi?)? even if you don't know MaxMSP, you must know how/in-what-format the pressure trigger sends its information to work with it at all in any environment. pretty much everything we'd translate from the real world into max would be in some form of 'electric signal' or another so we need something less vague to be more specifically helpful.
      otherwise, a guess in the dark like this(patch detects amplitude threshold of signal and translates to a single bang which can be used to trigger something in max) might not be very useful to you:
      ________________________________ *Never fear, Noob4Life was never here!*
    • Dec 11 2010 | 9:07 pm
      Ok! Thank you! I'll talk with the people in charge of this to get more informations.
    • Dec 11 2010 | 9:33 pm
      If your hardware triggers are part of an interface like Arduino or the MAKE controller, for example, then the communication part is pretty much done already. But if you need to convert a raw electric current to something for the computer, you'll need something in between, as mentioned... lots of options, but many are more work than probably is desirable. Microphone is definitely one of the easiest.
      You can also get a ton of interaction via cameras and jitter, which you probably know...
      and by the way, your English sounds great to me! I wish I had that ability level in a non-native language... alas
    • Dec 11 2010 | 9:38 pm
      "and by the way, your English sounds great to me!"
      i agree with seejay :)
      ________________________________ *Never fear, Noob4Life was never here!*