search

martindinov / hackathon

Where we will store all our hackathon-related code and files.
0 stars 2 forks source link

Number of channels and using sound cards #5

Open nmdanr2b opened 9 years ago

nmdanr2b commented 9 years ago

For the initial prototype two data input channels and one stimulation output channel are sufficient. In the future the number of input channels can be increased to 16 or more. Two output channels for stimulation are likely to suffice. Note that it is easy to add more output channels simply by sticking sound cards to USB ports, however these channels will be under sound card limitations. Cheap sound cards do not have a cap on 20 Hz, however there will still be power limitations (1, max 2 V output), and the available audio amps do cut the frequency range at about 20 Hz. Even with such an amp, USB sound cards would probably be suitable for the (controversial, but very interesting) weak field TMS only. However, they can be used directly - to play sound in response to EEG change (whether for evoked potentials studies, neurofeedback or sheer entertainment).

P.S.: usability of Pi phono jack as output channel should be investigated

nmdanr2b commented 9 years ago

Single stimulation channel can be split into several supporting the same signal with simple cable splitting. Loss in amplitude to be measured and accounted for in such a case.