response unit for E-prime 2.0 Professional with ERP hardware

Mon Feb 4 17:00:24 UTC 2013

Margot,

What Paul said-- in particular, the SRBox does not send "random" 
bytes.  It does have a jumper inside to switch between transmission 
rates of 9600 or 19.2K baud.  It has other jumpers to switch between 
character rates of 800 or 1600 cps -- 800 cps means 1.25 ms between 
data, 1600 cps means a mere 0.625 ms between data.  This is all 
explained in the manual that should accompany the SRBox.

It really is a neat little device once you understand it.  The 
easiest way to see this is by using any terminal emulator (note that 
you must transit a byte to the SRBox with bit 7 set high in order to 
enable data transmission from the SRBox; sending a byte with bit 7 
set low will stop data transmission -- this is *not* documented!).

-- David McFarlane

At 2/3/2013 04:36 PM Sunday, Paul Groot wrote:
>Hi Margot,
>
>The SRBox devices sends a continuous stream of bytes representing 
>the button status. If I remember correctly, there is a mode switich 
>to select 9600 or 19200 bytes per second. I think the continuous 
>stream makes it possible to make the response times more accurate. 
>However, you will need a kind of device driver that deals with the 
>continuous stream in a background process. I have created such 
>driver as a so called Windows COM-object, several years ago, but I 
>don't think that will be compatible with Matlab.
>
>Best,
>Paul
>
>On 2 February 2013 02:51, Margot Elizabeth 
><<mailto:turquoised13 at gmail.com>turquoised13 at gmail.com> wrote:
>We gave up on using E-Prime to present videos of 7000 ms in length; 
>they just wouldn't run reliably. Instead we went to Matlab, then 
>discovered that the PST SRBox is sending random bytes to Matlab 
>which are being misinterpreted as button presses. The biggest 
>consequence is that Matlab skips presenting videos unpredictably 
>when there is extra information in the buffer.
>I'm using the same SRBox for an audio experiment that E-Prime is 
>presenting, so of course I was concerned when I discovered the 
>visual bug. E-Prime evidently "knows" about the problem because 
>NetStation isn't recording more than one button press during the 
>audio experiment.
>Has anyone else had this problem? It does not appear to be the 
>cable. Moving the cable, even violently! :)), does nothing to the 
>amount of noise we're recording; in contrast, button presses, 
>particularly late in the video presentation just before a timeout, 
>do. Do these boxes send random bytes of information that E-Prime 
>deals with routinely, or is there some problem with the way we've 
>set it up (e.g., grounding?). Or maybe it's a defective box. The 
>'wait' code for Matlab from this thread lessened the problem but 
>didn't solve it.
>thanks,
>Margot
>
>On Tue, Jun 19, 2012 at 2:43 PM, Chris Jones 
><<mailto:c.jones.phd at gmail.com>c.jones.phd at gmail.com> wrote:
>I'd also like to thank Ben very much for this information.  I came 
>to this group looking for instructions on how to build a serial or 
>parallel response box.  My department won't be able to approve a 
>response box until the fall and I want some data now...
>
>The game controller option makes sense for so many reasons, 
>including the psychological effect or context effect - perhaps 
>pulling for more valid data - particularly in a stop signal 
>paradigm.   Seems to fit with what Mich (Psychology, Nottingham; 
>sorry don't have thread handy) elsewhere about psychological effects 
>as being under-rated in comparison with timing precision...
>
>Just to review: I can use a Logitech game pad - for example 
><http://www.logitech.com/en-ca/gaming/controllers/7360>http://www.logitech.com/en-ca/gaming/controllers/7360
>
>and download a driver...  I don't actually see a place to download 
>drivers of the type Ben describes, but there is this information:
>
>____________________________________
>
>DirectInput (D)
>
>DirectInput mode works with Windows drivers to enable basic input 
>functionality. This input mode also lets you use the Logitech Gaming 
>Software to customize the inputs for games that don't normally allow 
>you to do so, or don't have gamepad support at all.
>
>You can use the Logitech Gaming Software with DirectInput mode to 
>assign a specific key or key combination to any of the buttons or 
>thumbsticks on the gamepad. You can also assign each thumbstick to 
>work like a joystick or mouse.
>
>NOTE: Logitech doesn't provide configuration software for 
>non-Windows systems, but many games allow you to configure inputs 
>in-game. DirectInput mode lets the gamepad communicate with the 
>drivers on many such systems.
>__________________________________________
>
>...And so using a driver and/or the above information, I will be 
>able to assign an ASCII key or number to one or more gamepad buttons, right?
>
>And e-prime will be able to add this device - as an input device or 
>the type, "response box"?
>
>And then what about the timing errors?   I'm not so concerned, but 
>can anyone estimate the timing errors for data logging?  Is there a 
>way to minimize the error by changing the input refresh rate somewhere?
>
>Thanks so much,
>Chris
>
>Chris Jones, Ph.D.
>Department of Psychology
>Kwantlen Polytechnic University
>Surrey, BC, Canada
>
>
>On Wednesday, April 22, 2009 6:17:25 AM UTC-7, ben wrote:
>i've used a couple different USB controllers for this purpose over 
>the years.  they're so much cheaper than the cedrus boxes or the pst 
>response boxes.
>both controllers i've used, and i would imagine all controllers of 
>this type, have an accompanying driver which you download from the 
>manufacturer's website and which allows you to assign a value to the 
>various controller buttons.  presses on the controller mimic 
>keyboard button presses, so all you need to do in eprime is set the 
>object collecting responses to look for a keyboard response (as 
>opposed to a response from a mouse or a pst response box).  for 
>instance, set the object to accept '0' or '1', and then assign one 
>button on the controller to be '0' and the other to be '1', turn off 
>all the other buttons, and you're good to go.
>pretty straight forward.
><http://www.logitech.com/index.cfm/gaming/pc_gaming/gamepads/devices/301&cl=US,EN>http://www.logitech.com/index.cfm/gaming/pc_gaming/gamepads/devices/301&cl=US,EN
>
>ben
>
>On Wed, Apr 22, 2009 at 7:56 AM, Jeffrey Bedwell 
><<mailto:jbedwell at mail.ucf.edu>jbedwell at mail.ucf.edu> wrote:
>
>Thanks for this info. Are you using this gamepad with E-Prime? If so,
>do you write script to tell the software how to interact with the
>gamepad?
>
>-Jeff
>
>On Apr 21, 9:20 am, baltimore.... at gmail.com wrote:
> > we use the logitech precision usb gamepad.
> >
> > On Apr 10, 2009 2:09pm, Jeffrey Bedwell <jbedw... at mail.ucf.edu> wrote:
> >
> >
> >
> > > Hi. I was wondering if anyone has suggestions for a button response
> > > unit to use with E-Prime 2.0 Professional in the context of ERP/EEG
> > > experiments? The PST response unit does not appear to be ideal for
> > > this because it has an A/C power cable coming up to the unit that may
> > > cause interference with the ERP signal. I'd like some type of video
> > > game controller or wireless unit that the participant can hold in
> > > their lap comfortably. Also, if it can plug into USB port, that may be
> > > ideal. Does anyone have any suggestions? Also, if anyone has
> > > successfully used the PST response unit in the context of ERP/EEG
> > > equipment, please let me know your thoughts on this. Thanks. I'd
> > > appreciate any feedback!
> > > Jeffrey S. Bedwell, Ph.D.
> > > Assistant Professor
> > > Department of Psychology
> > > University of Central Florida- Hide quoted text -
> >
> > - Show quoted text -

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