ButtonBoxes

General

The buttonbox is used for time accurate(1ms) button press registration. We use it to register buttonpresses, soundkey, voicekey signals and to send tone onset, analog output, triggers with the BITSI protocol. It is suitable for Behavioral, EEG, MEG, and fMRI experiments. The buttonbox is connected to a computer with a usb connection.

The output connector has two binary eight bit ports: input and output. The two ports can be used for responses (input) and stimulus triggers (output). Two 8 bits analog outputs and three 8 bits analog inputs. The output connector has a sound and voicekey which triggers when a amplitude reaches a threshold. By using the serial port, the BITSI can be used platform independently: it works on Windows, Linux and Mac OSX. Most programming environments and stimulus packages support serial communication. 

BITSI Protocol

BITSI stands for Bits to Serial Interface. Because the BITSI is designed to interface both in- and output signals, the 'protocol' is asymmetric: the input and output protocols differ. 

Input

The input port can be used to interface eight buttons maximally. Button presses are translated to serial output characters/bytes according to the following table:

Signal / Button	ASCII (rising / falling)	Code (rising / falling)
1	A / a	65 / 97
2	B / b	66 / 98
3	C / c	67 / 99
4	D / d	68 / 100
5	E / e	69 / 101
6	F / f	70 / 102
7	G / g	71 / 103
8	H / h	72 / 104
SoundKey	S / s	83 / 115
VoiceKey	V / v	86 / 118

This means that when signal 1 gets /activated?, a capital A will be sent to the serial port. A lowercase 'a' will be sent when the signal is deactivated?. Mechanical buttons can be connected directly.

Output

Output knows two protocols: BITSI simple or BITSI extended. To enter a certain protocol two buttons have to be pressed when the BITSIbox is powered. Press button H and A for simple mode and H and B for extended mode.

If no button is pressed when powered it boots the last known protocol. In the simple protocol every byte sent to the BITSI over the serial port, is represented at the 8 bit output.

The extended protocol uses two bytes?, this combination can access two analog outputs and a tone generator. The first byte selects the output. The second byte determines the value written to this output.

Function	Byte 1 (ASCII / code)	Byte 2
Marker out	M / 77	Marker value
Analog out 1	Y / 89	Analog output value
Analog out 2	Z / 90	Analog output value
Tone	T / 84	Start tone
Detect Sound	D	S / 83
Detect Voice	D /	V / 83
Calibrate Sound	C /	S
Calibrate Voice	C /	V
Analog in 1	A /	1
Analog in 2	A /	2
Analog in 3	A /	3
Analog in 4	A /	4
LEDs off	L /	X
LEDs input	L /	I
LEDs output	L /	O

== Trigger port settings

[[File:]]

The 25 pins female connector has 8 inputs and 8 outputs, respectively 1-8 are inputs and 9-16 are outputs. Three analog input with an analog to digital convertor of 12 bit, pins 17,18,20 and 21. Two analog outputs with an digital to analog convertor of 12 bits on pins 22 and 23.

Serial port settings

Our hardware design allows to be connected to the computers USB and emulates a serial Port.

Baudrate	115200
Parity	none
Data bits	8
Stop bits	1
Flow control	none

Presentation Settings

File:Buttonbox1.png

Psychopy Settings

 #!/usr/bin/env python

 from psychopy import core, visual, event from rusocsci import buttonbox import logging, time

 ##Setup Section
 #logging.getLogger().setLevel(logging.DEBUG) # use this for debug info

 win = visual.Window([400,300], monitor="testMonitor") bb = buttonbox.Buttonbox()

 ##Experiment Section

 b = bb.waitButtons(maxWait = 10.0, buttonList=['A']) print("b: {}".format(b))

 ##Cleanup Section

 core.quit() The following script lights the LEDs under the buttons pressed.

 #!/usr/bin/env python
 #from __future__ import print_function

 import logging, time, sys from rusocsci import buttonbox

 ##Setup Section

 led = [False]*8

 ##Experiment Section

 bb = buttonbox.Buttonbox() while True:

  buttons = bb.getButtons()
  if len(buttons):
  for c in buttons:
  if ord(c) >= ord('a') and ord(c) < ord('a')+8:
  led[ord(c) - ord('a')] = False
  elif ord(c) >= ord('A') and ord(c) < ord('A')+8:
  led[ord(c) - ord('A')] = True
  bb.setLeds(led)
  #print("buttons ({:3d}): {}{}".format(len(buttons), buttons, " "*50), end="\r")
  #sys.stdout.flush()

Matlab Settings

 ===================================================================================================
 function handle = serial_buttonbox_common(cmd,varargin)
 % to initialize connection:
 % handle = serial_buttonbox('open',se)
 %    settings (se):
 %       define settings as a structure, i.e.:
 %       se.Device    = 'COM1';
 %       se.BaudRate  = 115200;
 %       se.DataBits  = 8;
 %       se.StopBits  = 1;
 %       se.Parity    = 0;
 %       se.PTBPath   = 'c:\MyToolboxes\PsychToolbox'
 %
 % to close the connection:
 % serial_buttonbox('close',handle);
 
 persistent old_hdl
 
 % set defaults
 se.Device    = 'COM1';
 se.BaudRate  = 115200;
 se.DataBits  = 8;
 se.StopBits  = 1;
 se.Parity    = 0;
 se.PTBPath   = 'c:\Pgrogram Files\PsychToolbox';
 
 if nargin < 1
    cmd = 'open';
 end
 if nargin > 1
    % user overwrites default settings
    flds = fields(varargin{1});
    for n = 1 : numel(flds)
       se.(flds{n}) = varargin{1}.(flds{n});
    end
 end
 
 
 switch cmd
    case 'open'
       addpath(genpath(se.PTBPath));
       % get handle to serial device
       handle = open_buttonbox(se.Device);
       return
    case 'close'
       handle = varargin{1};
       IOPort('close',handle);
       return
    case 'run'
       % read incoming data
       if isempty(old_hdl)
          help serial_buttonbox_common
          error('Buttonbox not yet initialized');
       end
       handle = old_hdl;
    otherwise
       fprintf('Unknown option %s\n',cmd);
       return
 end
 
 % only gets here when cmd = 'run'
 while 1  
    % start polling for characters (indicating start of scan)
    navailable = IOPort('BytesAvailable', handle);
    if navailable
       data = [];
       while navailable
          % read incoming data
          [newdata, ~, err] = IOPort('Read', handle, 0, navailable);
          if ~isempty(err), disp(err); end
          data = [data newdata];
          %pause(0.001); % if possible just add a small pause to not claim entire core
          navailable = IOPort('BytesAvailable', handle);
       end
       if numel(data)>1
          fprintf('\nReceived characters: %d\n',numel(data));
       end
       for n = 1 : numel(data)
 %        disp(char(data(n)));
          fprintf('incoming: %d\t%s\n',data(n),char(data(n)));
       end
    end
   
   
 end %while 1
 
    function hdl = open_buttonbox(device)
       % open handle to serial device (mini buttonbox)
       try
          hdl = IOPort('OpenSerialPort',device,['BaudRate=' num2str(se.BaudRate)]);
       catch
          if ~isempty(old_hdl)
             IOPort('close',old_hdl);
          end
          hdl = IOPort('OpenSerialPort',device,['BaudRate=' num2str(se.BaudRate)]);
       end
       old_hdl = hdl;
      
       fprintf('Wait for device buttonbox....\n');
       tic
       while ~IOPort('BytesAvailable', hdl) && toc<10
          % wait for welcome message device
       end
       pause(0.5);
 
       % clear buffer
       %IOPort('flush', hdl);
       IOPort('purge', hdl);
    end
  
 end

Inquisit Settings

Work in progress

E-Prime

Work in progress