Hi Chris,
I was chatting with Mariana regarding using the Arduino to synch mworks with blackrock. She reminded me that because blackrock samples at such a high rate, the fact that the arduino send each byte of the word sequentially, it is programmatically challenging when combing mworks with blackrock files to find the corresponding words in each file.
As Mariana describes it: “what the firmata protocol does is sequentially alters the pins in the word. If the receiving end is a fast process, e.g. BlackRock which runs at 30KHz, at such high sampling rate the words are getting registered on blackrock sequentially (multiple words instead of a single word).” Mariana was wondering if there might be a way to make the communication more parallel than serial?"
I am also curious as to how other people are synching their stimuli with physiological recordings, you mentioned that Ko is no longer using ITC-18, and that nobody in Jim’s lab is using open ephys.
Best
Najib
Hi Najib,
Mariana was wondering if there might be a way to make the communication more parallel than serial?
It might be possible to reduce the number of messages that MWorks sends to the Firmata device, though I don’t know if that would solve the problem. The basic issue is that the Firmata protocol doesn’t support word output, so MWorks has to fake it by sending a bunch of pins values at once. As you’ve discovered, this isn’t an ideal solution.
Shouldn’t it be possible to resolve this on the Blackrock side? Looking at the user manual for the Blackrock Cerebus, I see that the 16-bit DB-37 input port has a dedicated “digital strobe” (DS) pin. I assume that setting that input from low to high triggers recording of all the input pins. If that’s true, then you should be able to configure your word as slowly as you want and then tell Blackrock to record it by setting the single DS pin. Or am I misunderstanding what “digital strobe” means?
I am also curious as to how other people are synching their stimuli with physiological recordings, you mentioned that Ko is no longer using ITC-18, and that nobody in Jim’s lab is using open ephys.
As I said when we spoke, last I heard, Ko was using an NI device to send sync words to the recording system. You’re correct that MWorks’ current options are limited. (Firmata, ITC-18, and NIDAQ are the only ones supported out of the box.) I don’t know the specifics of what other folks are doing.
Chris