udev, C, python and gyro... about emokit

[antoche]

Update on the C situation: by default I get garbage, but if I change type from 0 to 1 in emokit.c line 40, I get correct data. The gyro data is skewed as in the python case, though.

I also noticed that running the C code makes the emokit's hidraw devices disappear, making the python script unusable until I unplug and re-plug the usb dongle. Is there a way to avoid that?

Cheers,
A.

[qdot]

Ah, yeah, that's my fault for not having report parsing in the C version then. I'm hoping to convert to HIDAPI soon (note: soon can sometimes take months for me :( ), which'll make that work automatically.

As for the hidraw device, yeah, I just noticed that too. We do a kernel detach to make linux's HID manager go away when we use libusb, and I don't think I ever reattach before closing. This is yet another thing just going to HIDAPI will fix. :)

[antoche]

Thanks for the reply. None of these issues are blocking for me right now, so it's fine. I'm still just puzzled about the gyro data not being 0 at rest, but I'm not using it right now so it's not blocking either.
I'm having a look at making an emokit acquisition driver in openvibe, I'll post something here if I get any success. I managed to get the data through to openvibe by modifying emokitd to make it output the binary data into a fifo and using openvibe's raw file reader (similar to http://www.giammy.com/files/bci.html#x1-200004.6.2 but simpler), but it's a bit crude.

[qdot]

Ah, hey, I'm doing that too! :D

Or, well, was. I started trying to do an acq server in OpenVibe a couple of months ago, just haven't had time to finish it. It's at

https://github.com/qdot/openvibe/tree/emokit-acquisition

If you're interested. Dunno if there's much different from yours.

Also: I'm working on the hidapi stuff now, hopefully will have the library done tonight or tomorrow. It's gonna be an API breaker, but I think this will work much better in the long run.

[antoche]

I'm pretty much at the same point: copy the Emokit-epoc driver, rip out the entrails and try to get it to compile to start with. :)

No worries about the API breaking for me. The code is simple enough to update it when needed.