psychopy.org | Reference | Downloads | Github

Using serial port with Parallel Port Out Component


#1

I am trying to use a serial port (via a USB-serial adapter) to send event markers from PsychoPy to COBI Studio (an fNIRS data acquisition software). I’ve achieved it via the Code component, but was really hoping to get it working with the Parallel Port Out component (following Jon’s response in this Google groups thread so it would be easier for a larger number of potential users (staff and students), but can’t get it working. My guess is that I am not specifying the port correctly… I’ve tried all the hex possibilities for COM4 (as well as just ‘COM4’) to no avail.

Any help would be greatly appreciated. In particular, how do I find the correct port name and what format does PsychoPy (v1.9.3 on Windows with Python 3.7.1) require this to be?

Thanks in advance! :grin:


#2

I’m really just wanting to know if it is possible (and, if it is, how), so that I can know whether to keep it in mind as an option or whether I should forget about it and move on. :blush:


#3

Serial ports and parallel ports are quite different beasts: I think you’ll find that linked post contained a typo about the parallel component using pyserial: it probably should have referred to pyparallel. With a parallel port, you’re controlling actual voltage levels on individual wires: even though serial ports are as old as the hills too, they do actually send information via bytes and are a bit more sophisticated.

Hardware and software-wise, you often don’t really have the freedom to choose which to use: that is determined by the ports on the equipment you are trying to interface with, and the API it uses.

So if you have serial port communication working via code, you’re already good to go?


#4

Thank you so much for taking the time to clarify this for me. My understanding was (and is) that they are different in the ways you describe, but I think I was lured into believing that perhaps the Parallel Out component had some conversion/translation capacity built in. As I now know this is not the case, I can persevere with my communication via code.

Thanks again! :slight_smile: