Welcome to the OpenEXG-2 project

Last Updated: 21 April 2009

A 2-channel biometric signal amplifier for EEG and other biological signal processing.


About the project

ModularEEG has been around for some years.  The car industry has progressed by about 1 and ½ car model generations during this period, technology moves on.  ModularEEG is a well performing device and should still be the design of choice for beginners.

Disadvantages of ModularEEG are the following:

  1. In today's RS232-less world, needing to fiddle with RS232-USB converters is clumsy;
  2. Having to use a wall-wart mains adapter is also a pain;
  3. The 10-bit resolution, although adequate, is on the low side.

EXG-2 is a modern, up-to-date design and has the following advantages:

  1. It is USB enable from out-of-the-box;
  2. It has 16-bit resolution and thus more dynamic range;
  3. Although technically advanced, it uses less components than ModularEEG;
  4. It has been designed to handle all biometric signals: EEG/ECG/EMG/EOG;
  5. It needs no wiring other than 5 short wires to the input connectors.  Everything else is mounted on a single PCB;
  6. The PCB has been dimensioned to fit into a specific plastic enclosure.

A design is always a compromise; EXG-2 has the following disadvantages:

  1. It is more expensive (but then you save on separate power supply and RS232/USB converter);
  2. It is only a 2-channel device (no expansion possibilities);
  3. It uses extremely small-pitched SMT components and thus cannot be soldered without some sort of optical magnification aid.
The project is developed and copyrighted by Stefan Jung. Webmaster of this site is Stephan Gerhard.

IMPORTANT WARNING

If you choose to build/use the hardware and/or software described on this website to do biofeedback training or experimentation on yourself or others, you do so ENTIRELY AT YOUR OWN RISK.

The software and hardware design is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY, EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Electrical safety should be regarded paramount and no modifications should be done to maintain the galvanic isolation.  The PCB SHOULD NOT be build into a metal enclosure as this too could compromise the isolation!

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