2 CallBack functions ? - SOLVED

Comments

• Arnaud Boré

  March 2017

  Oops I think I already have my answer. Everything is already logged even using keyboard.check.
• fladd

  March 2017

  Hi there,

  can you give a code example?

  In general, though, if you need very stable and precise audio timing, I would suggest to have the audio played by a dedicated hardware audio sampler, triggered via MIDI from the PC that records the responses.

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• Arnaud Boré

  April 2017 edited April 2017

  So far I was just testing some basic code, but I notice that it may miss a tone sometime. What would be your suggestion ? Thank you in advance.

  from expyriment import control, stimuli, io, design, misc
  from expyriment.misc import constants
  from expyriment.misc._timer import get_time
  
  from config import *
  
  if not windowMode:  # Check WindowMode and Resolution
      control.defaults.window_mode = windowMode
      control.defaults.window_size = misc.get_monitor_resolution()
      windowSize = control.defaults.window_size
  else:
      control.defaults.window_mode = windowMode
      control.defaults.window_size = windowSize
  
  exp = design.Experiment('test')  
  
  trigger = io.Keyboard()
  control.initialize(exp)
  
  tone1 = stimuli.Tone(50, 675)
  tone1.preload()
  
  def my_callback():
      """Quit all event loop with mouse press"""
      global exp
      key = trigger.check([49,50,51,52])
  
  control.register_wait_callback_function(my_callback)
  control.start(exp, auto_create_subject_id=True, skip_ready_screen=True)
  
  while True:
      tone1.play(maxtime=50)
      exp.clock.wait(2000)
  
• fladd

  April 2017

  To be honest, I do not understand what you are aiming to do in that code. The my_callback function does not do anything it seems (well, it checks for the keys, but it does nothing with the results of that check).

  If I do understand correctly what you are trying to achieve, then here are two ways to achieve this:

  1)

  from expyriment import control, stimuli, io, design, misc
  
  
  control.set_develop_mode()
  exp = control.initialize()
  
  tone1 = stimuli.Tone(50, 675)
  tone1.preload()
  
  control.start(exp, auto_create_subject_id=True, skip_ready_screen=True)
  
  times = []
  while True:
      tone1.play()
      duration = 2000
      while True:
          key, rt = exp.keyboard.wait([49,50,51,52], duration=duration)
          if rt is None:
              break
          else:
              times.append(exp.clock.time)
              duration -= rt
  

  2)

  from expyriment import control, stimuli, io, design, misc
  
  control.set_develop_mode()
  exp = control.initialize()
  
  tone1 = stimuli.Tone(50, 675)
  tone1.preload()
  
  def callback():
      global exp
      global times
      key = exp.keyboard.check([49,50,51,52])
      if key is not None:
          times.append(exp.clock.time)
  
  control.register_wait_callback_function(callback)
  control.start(exp, auto_create_subject_id=True, skip_ready_screen=True)
  
  times = []
  while True:
      tone1.play()
      exp.clock.wait(2000)
  

  I want to stress again, though, that if you need perfect timing, an external device is the way to go.

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• Arnaud Boré

  April 2017

  I know that nothing has been written as a data file but everything is logged in the events folder and it's what I was looking for. Thank you for your advice.
• Arnaud Boré

  April 2017

  I don't think I need perfect timing but what would be the worst case scenario if I keep this kind of script ?
• fladd

  April 2017

  The worst case scenario is that you have a jitter of unknown size, leading to (a) you not knowing when exactly the sound was actually played via the speakers, and (b) an unstable rhythm, when playing back sounds consecutively like you do.

  Warning There was an error rendering this rich post.