Re: [buildcheapeeg] Re: New schematic and layout + New List Member

From: Jim Meissner (jpmeissner_at_mindspring.com)
Date: 2002-01-21 13:33:32


Dear Giovanni:

> For example, I've just used Bascom to program up a precision low
> frequency synthesised sinewave generator using the 2313 to let me
> generate 7.81Hz, 7.83Hz, 8.00Hz to accuracies of 0.001Hz

Would you guide me as to how to build this? Do you sell these things or can you guide me where to get the hardware and software. I am presently using an 8038 analog sine wave generator chip that works well, but you need a counter to set the frequency. It would be nice to have digital control!

> to see if I can
> detect any effect from low frequency magnetic fields - really odd - I
> can feel the pulsing - only a few mA with a 5V swing if I'm close to the
> coil. This is following up on the report from Robert Beck at
> http://www.elfis.net/elfol8/e8elfeeg2.htm - does anyone on this list
> know of any of the frequencies to be **avoided** in magnetic
> entrainment?

The Mind-l group has a shatki subgroup that plays with magnetic stimulationof the brain. If you need a better link and who it is, let me know and I will look in my old Emails.

I have some strong personal opinions about good and bad frequencies and entrainment that run counter to this group's concepts of how the brain works. Ask me privately if you want that information.

Juergen P. (Jim) Meissner
Check out my Website at www.MeissnerResearch.com
Read about the benefits of the Brain State Synchronizer sounds for improving your life and health.
----- Original Message -----
From: Giovanni Moretti
To: buildcheapeeg_at_yahoogroups.com
Sent: Friday, January 18, 2002 1:23 AM
Subject: RE: [buildcheapeeg] Re: New schematic and layout + New List Member

Hi Guys & Gals

Let me introduce myself - Giovanni Moretti from New Zealand - CompSci
Lecturer with an electronics & microcontroller background. Interested in
the same sort of oddball stuff I've seen go past on this list in the
last two days. Nice to find some other technically competent loonies :-)

Whilst searching for some more up-to-date microcontroller info than the
8051's I'd been using I came across the SimmStick systems from
Dontronics - it's basically a Lego-like kitset approach to prototyping
microcontrollers, including both PIC, AVR and 8051 series. I use these
for my own prototyping (click on my site link below for more info).

> I am really excited about the project and it
> is actually the sole reason that I am starting to get
> interested in electronics and actually ordered a starterkit
> for programming Atmels AVR-processors today :-).

Joel, the fragment in your email that prompted me to reply was the part
about getting started with AVRs - No I'm NOT trying to sell you
something :-), but you might like to check out the FREE basic compiler
for the AVR micros from www.mcselec.com - It's a wonderful TurboPascal/C
like environment for developing AVR systems and is especially good as it
has a LARGE number of interface subroutines predefined(EG button
debounce, serial drivers, LCD drivers 4 & 8 bit, keypad decoders, IR
infra-red decoders ...). The free version will compiler up to 1K of code
- that's enough to fill the AT90S2313 20pin AVR CPU (which you can get
from www.digikey.com for about $4). For more code you have to register
the compiler but for many projects the free compiler and the 2313 AVR is
sufficient.

For example, I've just used Bascom to program up a precision low
frequency synthesised sinewave generator using the 2313 to let me
generate 7.81Hz, 7.83Hz, 8.00Hz to accuracies of 0.001Hz to see if I can
detect any effect from low frequency magnetic fields - really odd - I
can feel the pulsing - only a few mA with a 5V swing if I'm close to the
coil. This is following up on the report from Robert Beck at
http://www.elfis.net/elfol8/e8elfeeg2.htm - does anyone on this list
know of any of the frequencies to be **avoided** in magnetic
entrainment?

Next project is a uP controlled GSR Audio feedback unit - so it
auto-zeros. My current one - (just op-amps and such) I have to keep
twiddling the knob as I relax and the frequency falls ...

> Joel wrote:
> It's hard to get started though, I have bought an experiment
> board and some components to test stuff with but there is
> much to learn before being able to do something useful. Any
> advice you can offer a beginner in electronics..? :-) Books,
> equipment, etc?

Joel, my one recommendation above all others would be to buy a cheap -
but calibrated oscilloscope (second hand would be fine - 10MHz or 20MHz
bandwidth, dual channel). The calibration is REALLY important - does it
have 5V, 2V, 1V, 0.5V, 0.2V down to 10mV per division and another one
with mS, and uS per division knobs? Working with electronics without a
scope would be like probramming with your eyes shut - the scope will
tell you things you won't find out any other way. It'll let you measure
DC volts, AC volts, frequency, pulse widths and that's just to start.
Also x10 scope probes are important - these reduce the (mainly
capacitive) load on whatever you're measuring. With a x1 probe, the
capacitance of the cable to the scope will alter the signal so what you
see is not quite as it was before you attached the probe.

I'm very interested in the EEG - I too would like just something that
(initially anyway) goes at all so I can SEE some of the stuff I've read
so much about. Just the front of head to the back (one channel) that
would be great. I've been loaned an old commercial 2 channel EEG (5
wires) but unfortunately it's owner has lost the manual and while I've
figured out which pairs of wires are the channels I'm not sure where on
my head to put them.

One point that became obvious even from just playing with the unit I've
been loaned is that - unless you're REALLY dedicated, most people aren't
going to like getting vast amounts of goo in their hair (well I find if
off-putting anyway :-) so the "market" (or no. of constructors) of
multichannel EEG will be very much small than one that simple does
front-to-back (one channel) or left and right hemispheres (two channel).

Enough rambling from me - any thoughts on where to place each of the
four EEG electrodes, and ELF magnetic entrainment frequencies - any
thoughts?

Enough of an intro - once you wind me up ... :-)

Cheers and thanks
Giovanni
========================================================================
====
Giovanni Moretti | FAST Atmel AVR, 2051 & PIC 16F84 development on
SimmStick
Palmerston North | Fringe Science, Brainwave Synchronisation, Remote
Viewing
New Zealand
|==========================================================
==== ZL2BOI =====| Visit Reflection Technology
http://www.reflections.co.nz

> -----Original Message-----
> From: Joel Eriksson [mailto:jen_at_ettnet.se]
> Sent: Friday, 18 January 2002 1:29 p.m.
> To: buildcheapeeg_at_yahoogroups.com
> Subject: Re: [buildcheapeeg] Re: New schematic and layout
>
>
> Hi Andreas,
>
> On Thu, Jan 17, 2002 at 11:42:28PM -0000, sleeper75se wrote:
> > > one wishes. Then only the multiplexer would have to be
> modified when
> > > someone wishes to make other interfaces (USB, Firewire, IrDA,
> >
> > USB is a nice idea. I've looked into it, and if you use the default
> > HID-drivers, you don't need to write any device drivers of your own.
> >
> > I could slap together a simple schematic using Philips
> PDIUSBD12 USB-
> > interface. On one end it talks USB, on the other it appears to talk
> > EPP (almost). Just connect the usb-port on one end and the parallel
> > port (with some adaptation logic) on the other. The rest would be
> > software.
>

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