Biological psychology experiment programming issue

Hi, bit of a novel use of XOJO that I need some help with, and a little bit of a complicated one too

I am using XOJO Desktop to create psychology experiments for project. These experiments will involve psychophysiological recording, done via PowerLab equipment from ADInstruments, and recorded with LabChart software on a second computer.

Powerlab info here:

And LabChart:

Basically, I need a way for XOJO to have code that

(a) sends a trigger signal to the Powerlab and starts the recording of data on Labchart


(b) Sends event-markers to LabChat during recording, so that the occurrence of stimuli on the screen can be synced with the biological responses.

Both would be done via connecting a parallel-port / BNC cable from the desktop XOJO-app-running computer to the powerlab’s digital input, which is then connected to the data-recording laptop via USB. The LabChart has software that can recognise events (in this case, each stimuli that appears on the screen in my XOJO-app) by having bytes assigned to them {e.g., stimulus “A” = 44, “B” = 33, if byte = 33, it’ll lay event marker with the comment “B”}

The latter one is probably more important for getting the project up and running, and even getting XOJO to send event markers with out labels would be workable

The main challenge appears to be getting XOJO software to communicate with LabChart via Powerlab, through parallel port - I’m not sure if this is entirely possible either.

Any advice would be much appreciated


My first advise is to not yell at us in the title already :wink:

You willmost likely need to install a suitable parallel port driver on the host computer and call the driver’s API functions through declares. At least, that is how I see it on Windows. probably similar on MacOS. Conceptually, I can see it being feasible. But the devil is in the details, as usual.

As Sasha suggested, perhaps you should modify the case of the thread title. We don’t like to be awaken by loud conversations during our afternoon nap.