Hello, I'm new to using the brainstorm digitization feature, and I could use some troubleshooting advice.
It appears that Fastrack Polhemus' configuration was successful. The tracking device is recognised by the brainstorm, but when recording, it provides two sets of xyz coordinates for a single button press. As a result, RPA is not being registered after Nasion and LPA. Additionally, no EEG electrodes are being recorded at all.
Here are the screenshots of the coordinates recorded through stylus and collect point option respectively.
Both the procedures generate the same error.
I only collected for Nasion data point here, and LPA data point was filled automatically.
I've checked all the previous issues and this is the first time that we have faced this issue. @Marc.Lalancette any idea for this one?
@ritu how many receivers do you have on your device?
Can you do the following:
in the Matlab command window, create the global variable
then print the SerialConnection info
you should have something like this:
Serial Port Object : Serial-COM6
then write to the serial port to collect a point
So this explains why then you are getting two values per acquisition.
If you want to use brainstorm digitize, you need just two receivers, the stylus plugged in channel 1, and then the fixed receiver plugged into channel 2.
PLease follow the instructions as stated on the tutorial.
Looks like you've figured it out, but that's an interesting "problem" and it would be a shame to force users to reduce robustness or accuracy if they have more receivers. Possibly something we could eventually improve in the future.
I'm curious though, may I ask how you use those receivers? Do you place them all on the head, and how are they placed and attached?
Also, just in case the receivers are not the issue, I vaguely recall there might be configuration options for outputting not only the location but also orientation of the stylus? That would also return more values than Brainstorm expects.
Yes, when I took the reading above, the third receiver was unplugged.
Even though the first sent command indicates "values sent=2" (initial signal value); following that, subsequent signals are treated as "values sent=initial signal value +1."
It appears to be functioning properly.