From: Jim Meissner (jpmeissner_at_mindspring.com)
Date: 2001-11-29 16:08:31
Dear Moritz:
I just joined this group and I am trying to figure out how I can help. I have a working EEG design that I built many years ago. The last time I usedit was in 1996. I found the hardware and last night found the software for the HC11 acquisition module and the waveform and FFT display for the PC. I transmitted 9600 Baud to the RS232 serial port through a simple opto isolator. I transmitted 5 bytes at 120 Hz. The bottleneck at the time was the 386 PC. I had to restrict the waterfall display to 20 time slices because there was not enough time to handle the serial port, do the FFT, and display the VGA data.
My comments about what I have seen in my brief time on this group are as follows:
1) The infrared interface is an overkill (and not cheap), a simple opto isolator and wires to the serial port works well.
2) An RF link would be nice improvement and I have seen that used.
3) I do not see that it is possible to build a usable EEG for $100 in parts. The HC11 board alone is $100.00.
4) The 555 voltage to pulse width converter that I saw here is cute and well designed, but tying up the PC handshaking it is pennywise and pound foolish. (See my comment about not enough time to do all the tasks)
Please tell me what this group has completed so far in the design?
How can I access the current design? What is SourceForge?
What areas do you need help in?
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: Moritz von Buttlar
To: buildcheapeeg_at_yahoogroups.com
Sent: Thursday, November 29, 2001 2:53 AM
Subject: [buildcheapeeg] I published current design at SourceForge
Hi !
I put the current the design on our SourceForge page. Check it out !
Beware, it's not tested yet. You also need the EAGLE software which you can get for free at htttp://www.cadsoft.de to print/edit circuit files and layouts. It's a modular version consisting of the analog amplifier 2-channelPCB and the digital uC PCB.
Please look and suggest improvements. Especially for the Disclaimer.
Have fun,
Moritz
----------------------
Moritz von Buttlar
moritz_at_v...
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