View source for Contributions:FlexEEG

==Synopsis==
This source module supports the FlexEEG system made by [https://www.neuroconcise.co.uk/ NeuroCONCISE Ltd].
Its key component is the ADC called <tt>NC_flexXADC</tt>.

==Location==
http://{{SERVERNAME}}/svn/trunk/src/contrib/SignalSource/FlexEEG

==Versioning==
===Authors===
Tony Moore, Jeremy Hill

===Version History===
* Revision r7860 2024-02-23 jhill: first debugged commit

===Source Code Revisions===

* Initial development: 7855--7860
* Tested under: 7860 (Windows)
* Known to compile under: 7860
* Broken since: --
* Known issues: (as at 7860) The API freezes if you press Set Config more than once per session.  Then you have to physically power-cycle the device before you can connect again.

==Functional Description==
This source module supports the FlexEEG systems made by [https://www.neuroconcise.co.uk/ NeuroCONCISE Ltd].

For best results, set the <tt>FlexEEGPort</tt> environment variable to specify the default serial port address for the computer you are using (e.g. <tt>COM9</tt> on Windows).
On Windows 11, the dialog that allows you to create or edit environment variables is at: Control Panel->System and Security->System->Advanced system settings->Environment Variables

==Installation==
The <tt>FlexEEG</tt> source module requires the <tt>flexX64.dll</tt> dynamic library. This is part of the manufacturer's API. The file must be placed in the <tt>prog</tt> directory.   A compiled version of the dynamic library for 64-bit Windows is supplied in the <tt>lib</tt> subdirectory, and will be copied to prog during the build process.

==Parameters==

===SampleBlockSize, SamplingRate, SourceCh, SourceChGain, SourceChOffset, TransmitChList===

These parameters are the same as for other BCI2000 source modules. For current devices (as at Feb 2024),
the '''SamplingRate''' should always be either 125 or 250.  The '''SampleBlockSize''' must be at least 24 (a
value of 25 at 250Hz gives you 100ms blocks).  The '''SourceChOffset''' values should be all 0 and the
'''SourceChGain''' values should be all 1 (or both can be left at "auto").

===PortName===

This is the port on which the headset connects, e.g. <tt>COM9</tt> on Windows.
You may lastingly set the default value on a particular computer by configuring a system environment variable called
<tt>FlexEEGPort</tt>.
    
===AcquisitionMode===

This allows you to switch between normal signal acquisition (code 0), acquiring a square-wave test signal (code 1), or
shorting the inputs for purposes of offset or noise measurement (code 2).

===DCfilter===

This turns on (1) or off (0) the device's built-in DC filter.

===Resolution===

This sets the device's digitization precision to 16-bit (code 1) or 24-bit (code 0).

==States==
    
===TODO===

Need a state that reflects the device's current battery level, and code for periodically querying the device and updating this state.

==Streams==

===Trigger===

Streams the digital trigger channels from the device (this device feature is still under development as at Feb 2024).

==See also==
[[Contributions:ADCs]]

[[Category:Contributions]][[Category:Data Acquisition]]