Interfacing With ViewPoint Eye Tracker
Last Revision: October 7, 2007

Summary

SuperLab 2.0 for Windows provided an optional "ViewPoint Eye Tracker" event type that allowed commands and strings to be sent to a ViewPoint eye tracker via a serial port.  SuperLab 4.0 does not have an explicit equivalent, but the same functionality can be accomplished via three "Serial Output" events using either the Mac or Windows version.

Details

There are two basic types of information that you can send to ViewPoint: commands and strings.  A command would be any valid ViewPoint command.  A string would be inserted in ViewPoint's data file as is, e.g. to provide an event marker.  Internally, the general format that SuperLab 2.0 used in order to send a command or event marker to ViewPoint is:

To Send a Command

'V'
'P'
11
size of string
actual string

To Send a String to Be Inserted Into Output File Directly

'V'
'P'
12
size of string
actual string

Easy enough, but the catch is that the numbers 11, 12, and "size of string" are binary numbers, thus necessitating that you use three serial output events instead of just one.

Here's an example.  Say you want to send the word "stimulus" as an event marker to be inserted in the output file.  You create three serial output events as follows:

• The first one sends a "String"; type "VP"

• The second one sends an "ASCII Value".  Type "12" and the length of the string that you are going to send.  In the case of our example, type "12 8"

• The third event sends a "String"; type "stimulus".

For the first two events at least, make sure to click on the Input tab and have the event ending option set to Immediately after the event is presented.

If you have questions about particular ViewPoint commands, please refer to the ViewPoint documentation.