From: sleeper75se (sleeper75se_at_yahoo.se)
Date: 2002-02-27 14:19:07
Hi Cyrus,
> Can I begin to collect parts for some of the building blocks of
these
> devices that will probably not go through much changes in the
future?
as you have noticed, the hardware isn't finished yet, so I'm not sure
you should start buying stuff just yet, except maybe electrodes.
Would you be interested in doing some design work? Digital/low
sensitivity analog only.... like designing, building and testing wide-
spaced opto-couplers (discrete led and photo diode)?
> I'd like to begin working on something that I can use in one of
these
> projects later - if the designs have not yet been finalized. An
> input stage? Microcontroller component of a design?
Hmm... tricky. Joergs new input stage looks pretty mature... my
design is too new and untested throughout.
>
> Tell me about some of these:
>
> modularEEG - is this the one discussed here and on openeeg.sf.net?
Yes.
> How complete are the plans to build this unit?
It is still being worked on. Joerg has made heavy modifications of
the input stage, and I'm not sure if he (or Moritz v Buttlar) has had
the time to draw a new PCB-layout yet. In brief, it is a 2-channel
device, 6-channels max, with a 10-bit ADC. It uses through hole parts.
> RS232EEG - I've seen some plans for this. Is it doable? Are there
If I understand it correctly, this is an older version of the
ModularEEG ... better to wait for the new one.
> board masks availible? I've heard it needs some safety work... Can
> I do without?
It depends on how you value your life. ;-) The safety work needed for
RS232EEG is: new DC/DC converter with higher isolation voltage (5000
volts) and better optocouplers. Joerg has addressed the first problem
but I don't know how he will tackle the second.
> TinyEEG - a Handspring Visor module would be a good place for
this :)
Yeah, it would be nice. Hard to go *that* tiny though. I'm still
working on the first version... the ultimate goal is to get a single
PCB packed with SMT-parts. It will be highly un-modular, and perhaps
not that easy to build for a beginner, but can perhaps be expandable,
with GSR/ESR and temperature addons. It has slightly higher
resolution than modularEEG (2 bits extra :-).
>
> HAL4 - is this worth building if I could get the plans and parts
> together?
Nope. I think it uses far too much current to be economical and there
are newer IC's and designs available that perform much better. A
BrainMaster (home built) would be a better option in this case.
> Standalone - Looks easy.... Thoughts?
Well, Pocket PC/Laptop + EEG device = standalone. :-) I'm not sure
handspring/palm is powerful enough for DSP-work, and custom designs
are just too tedious. Doug Sutherland is probably the right person to
discuss this with.
>
> BrainMaster - the old standby?
Maybe, but ... depends on how much in a hurry you are. If you can
find the plans for BrainMaster, you could build it now rather than
waiting for either Joerg or me. But it is a bit old, and has only two
channels and 8-bit resolution.
> I'm also curious about the relationship between >openeeg.sf.net<
and
> this >buildcheapeeg< Yahoo! group. Is the bbs.circuitcellar.com
> local.cci.hal4 list totally dead and everybody has moved here?
Once the software part starts to grow, I think we will be moving the
development to sf.net... Yahoo groups is good for discussions, but
perhaps not for maintaining software. :-)
Regards,
Andreas
> Much thanks to all! I hope to get started soon!
> Cyrus
This archive was generated by hypermail 2.1.4 : 2002-07-27 12:28:39 BST