Programming Tutorial:Implementing a Source Module - Revision history

Mellinger: /* ADC Initialization */

2022-07-08T15:47:57Z

ADC Initialization

← Older revision		Revision as of 15:47, 8 July 2022
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	Parameter("SampleBlockSize"),		Parameter("SampleBlockSize"),
	SignalType::int16 );		SignalType::int16 );
	outputProperties.ChannelLabels[](Parameter( "SourceCh" )) = "@DigitalInput";		outputProperties.ChannelLabels()[Parameter( "SourceCh" )] = "@DigitalInput";
	}		}
	</pre>		</pre>

Mellinger at 17:57, 27 April 2022

2022-04-27T17:57:10Z

← Older revision		Revision as of 17:57, 27 April 2022
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	To simplify the process of creating a source module, there is a helper program		To simplify the process of creating a source module, there is a helper program
	located at <tt>build/NewBCI2000Module</tt>. When being run, it will create the files required for		located at <tt>build/NewBCI2000Module</tt>. When being run, it will create the files required for
	a source module from templates. Still, the following may be helpful for you to read, even if you		a source module from templates, with extensive comments detailing implementation steps and decisions.
			Still, the following may be helpful for you to read, even if you
	are going to use <tt>NewBCI2000Module</tt>.		are going to use <tt>NewBCI2000Module</tt>.

Mellinger at 17:52, 27 April 2022

2022-04-27T17:52:53Z

← Older revision		Revision as of 17:52, 27 April 2022
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	<pre>		<pre>
	#define TACHYON_NO_ERROR 0		#define TACHYON_NO_ERROR 0
	int TachyonStart( int inSamplingRate~~, int inNumberOfChannels~~ );		void* TachyonOpen();
	int TachyonStop( void );		int TachyonClose(void* handle);
	int TachyonWaitForData( short** outBuffer, int inCount );		int TachyonGetNumberOfChannels(void* handle);
			int TachyonStart(void* handle, int inSamplingRate);
			int TachyonStop(void* handle );
			int TachyonWaitForData(void* handle, short** outBuffer, int inCount);
	</pre>		</pre>
	From the library help file, you learn that <tt>TachyonStart</tt>		From the library help file, you learn that <tt>TachyonStart</tt>
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	<pre>		<pre>
	TachyonADC::TachyonADC()		TachyonADC::TachyonADC()
	: mSourceCh( 0 ),		: mSourceCh(0),
	mSampleBlockSize( 0 ),		mSampleBlockSize(0),
	mSamplingRate( 0 )		mSamplingRate(0),
			mHandle(nullptr)
	{		{
	}		}
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	TachyonADC::~TachyonADC()		TachyonADC::~TachyonADC()
	{		{
			if (mHandle)
			TachyonClose(mHandle);
	}		}

Line 111:		Line 117:
	{		{
	BEGIN_PARAMETER_DEFINITIONS		BEGIN_PARAMETER_DEFINITIONS
	"Source int SourceCh= ~~64 64 1 128~~ "		"Source int SourceCh= auto auto % % "
	"// this is the number of digitized channels",		"// this is the number of digitized channels",
	"Source int SampleBlockSize= 16 5 1 128 "		"Source int SampleBlockSize= 16 5 1 128 "
	"// this is the number of samples transmitted at a time",		"// this is the number of samples transmitted at a time",
	"Source int SamplingRate= ~~128 128~~ 1 4000 "		"Source int SamplingRate= 128Hz 128Hz 1 4000 "
	"// this is the sample rate",		"// this is the sample rate",
	END_PARAMETER_DEFINITIONS		END_PARAMETER_DEFINITIONS
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	void TachyonADC::OnAutoConfig()		void TachyonADC::OnAutoConfig()
	{		{
	Parameter("SourceCh") = TachyonGetNumberOfChannels();		if (mHandle)
			TachyonClose(mHandle);
			mHandle = TachyonOpen();
			if (!mHandle)
			throw bcierr << "Could not connect to Tachyon hardware";
			Parameter("SourceCh") = TachyonGetNumberOfChannels(mHandle);
	}		}
	</pre>		</pre>
Line 149:		Line 160:
	signal:		signal:
	<pre>		<pre>
	void TachyonADC::OnPreflight( SignalProperties& outputProperties ) const		void TachyonADC::OnPreflight(SignalProperties& outputProperties) const
	{		{
	if( TACHYON_NO_ERROR != TachyonStart( Parameter( "SamplingRate" )~~, Parameter~~( ~~"SourceCh"~~ ) ) )		if(TACHYON_NO_ERROR != TachyonStart(mHandle, Parameter("SamplingRate").InHertz()))
	bcierr << "SamplingRate and/or SourceCh parameters are not compatible"		bcierr << "SamplingRate and/or SourceCh parameters are not compatible"
	<< " with the A/D card";		<< " with the A/D card";
	outputProperties = SignalProperties( Parameter( "SourceCh" ) + 1,		TachyonStop(mHandle);
	Parameter( "SampleBlockSize" ),		outputProperties = SignalProperties(Parameter("SourceCh") + 1,
			Parameter("SampleBlockSize"),
	SignalType::int16 );		SignalType::int16 );
	outputProperties.ChannelLabels[](Parameter( "SourceCh" )) = "@DigitalInput";		outputProperties.ChannelLabels[](Parameter( "SourceCh" )) = "@DigitalInput";
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	Thus, you may skip any further checks, and write		Thus, you may skip any further checks, and write
	<pre>		<pre>
	void TachyonADC::OnInitialize( const SignalProperties& )		void TachyonADC::OnInitialize(const SignalProperties&)
	{		{
	mSourceCh = Parameter( "SourceCh" );		mSourceCh = Parameter("SourceCh");
	mSampleBlockSize = Parameter( "SampleBlockSize" );		mSampleBlockSize = Parameter("SampleBlockSize");
	mSamplingRate = Parameter( "SamplingRate" );		mSamplingRate = Parameter("SamplingRate");
	}		}
	</pre>		</pre>
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	void TachyonADC::OnStartAcquisition()		void TachyonADC::OnStartAcquisition()
	{		{
	int err = TachyonStart( ~~mSourceCh~~, mSamplingRate );		int err = TachyonStart(mHandle, mSamplingRate);
	if( err != TACHYON_NO_ERROR )		if( err != TACHYON_NO_ERROR )
	bcierr << "Could not start acquisition due to error " << err;		bcierr << "Could not start acquisition due to error " << err;
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	int valuesToRead = mSampleBlockSize * (mSourceCh + 1); // +1 for DigitalInput		int valuesToRead = mSampleBlockSize * (mSourceCh + 1); // +1 for DigitalInput
	short* buffer;		short* buffer;
	int err = TachyonWaitForData( &buffer, valuesToRead );		int err = TachyonWaitForData(&buffer, valuesToRead);
	if( err == TACHYON_NO_ERROR )		if (err == TACHYON_NO_ERROR)
	{		{
	int i = 0;		int i = 0;
	for( int channel = 0; channel < mSourceCh + 1; ++channel )		for (int channel = 0; channel < mSourceCh + 1; ++channel)
	for( int sample = 0; sample < mSampleBlockSize; ++sample )		for (int sample = 0; sample < mSampleBlockSize; ++sample)
	outputSignal( channel, sample ) = buffer[ i++ ];		outputSignal(channel, sample) = buffer[i++];
	}		}
	else		else

Mellinger: /* ADC Initialization */

2022-04-27T17:38:20Z

ADC Initialization

@@ Line 127: / Line 127: @@
 If your amplifier/DAC has digital inputs, use such a stream to record them and make them available
 to BCI2000 components through the [[Technical_Reference:State_Definition#State_Concept|<tt>State</tt>]] interface.
 ==ADC Initialization==

Mellinger: /* Writing the ADC Header File */

2022-04-27T17:31:38Z

Writing the ADC Header File

← Older revision		Revision as of 17:31, 27 April 2022
Line 65:		Line 65:

	void OnPublish() override;		void OnPublish() override;
			void OnAutoConfig() override;
	void OnPreflight(SignalProperties&) const override;		void OnPreflight(SignalProperties&) const override;
	void OnInitialize(const SignalProperties&) override;		void OnInitialize(const SignalProperties&) override;

Mellinger: /* Data Acquisition */

2022-04-27T17:25:14Z

Data Acquisition

← Older revision		Revision as of 17:25, 27 April 2022
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	void TachyonADC::DoAcquire( GenericSignal& outputSignal )		void TachyonADC::DoAcquire( GenericSignal& outputSignal )
	{		{
	int valuesToRead = mSampleBlockSize * mSourceCh;		int valuesToRead = mSampleBlockSize * (mSourceCh + 1); // +1 for DigitalInput
	short* buffer;		short* buffer;
	int err = TachyonWaitForData( &buffer, valuesToRead );		int err = TachyonWaitForData( &buffer, valuesToRead );
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	{		{
	int i = 0;		int i = 0;
	for( int channel = 0; channel < mSourceCh; ++channel )		for( int channel = 0; channel < mSourceCh + 1; ++channel )
	for( int sample = 0; sample < mSampleBlockSize; ++sample )		for( int sample = 0; sample < mSampleBlockSize; ++sample )
	outputSignal( channel, sample ) = buffer[ i++ ];		outputSignal( channel, sample ) = buffer[ i++ ];
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	}		}
	</pre>		</pre>
			As you can see, we read one more channel than the number of signal channels. This is because <tt>TachyonWaitForData()</tt> gives
			us one more value for the digital input, which we put into the last channel. Your code may look more complicated than this if you
			need to call a separate function to obtain the state of the digital input.
			In any case, it is important to understand that you cannot access states directly from <tt>DoAcquire()</tt> because it runs in a
			separate thread. Also, stream states such as <tt>DigitalInput</tt> need to be synchronized with signal data as it is acquired, rather
			than as it is sent from source to other BCI2000 components.

	==Adding the ''SourceFilter''==		==Adding the ''SourceFilter''==

Mellinger at 17:17, 27 April 2022

2022-04-27T17:17:02Z

← Older revision		Revision as of 17:17, 27 April 2022
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	bcierr << "SamplingRate and/or SourceCh parameters are not compatible"		bcierr << "SamplingRate and/or SourceCh parameters are not compatible"
	<< " with the A/D card";		<< " with the A/D card";
	outputProperties = SignalProperties( Parameter( "SourceCh" ),		outputProperties = SignalProperties( Parameter( "SourceCh" ) + 1,
	Parameter( "SampleBlockSize" ),		Parameter( "SampleBlockSize" ),
	SignalType::int16 );		SignalType::int16 );
			outputProperties.ChannelLabels[](Parameter( "SourceCh" )) = "@DigitalInput";
	}		}
	</pre>		</pre>
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	You might want to write <tt>SignalType::int32</tt> or <tt>SignalType::float32</tt> instead if your data acquisition hardware acquires data in one of those formats.		You might want to write <tt>SignalType::int32</tt> or <tt>SignalType::float32</tt> instead if your data acquisition hardware acquires data in one of those formats.

			Note that we allocate one more channel than the number of signal channels. This channel is for the digital input, which is a
			stream state, and as such not accessible from the helper thread our acquisition code runs in.
			By naming it <tt>@DigitalInput</tt>, we tell the framework to copy the channel's content into the stream state called "DigitalInput".

	The actual <tt>OnInitialize</tt> function will only be called if <tt>OnPreflight</tt> did not report any errors.		The actual <tt>OnInitialize</tt> function will only be called if <tt>OnPreflight</tt> did not report any errors.

Mellinger at 17:10, 27 April 2022

2022-04-27T17:10:12Z

← Older revision		Revision as of 17:10, 27 April 2022
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	"// this is the sample rate",		"// this is the sample rate",
	END_PARAMETER_DEFINITIONS		END_PARAMETER_DEFINITIONS

			BEGIN_STREAM_DEFINITIONS
			"DigitalInput 8 0 0 0", // a stream that holds digital input data
			END_STREAM_DEFINITIONS
	}		}
	</pre>		</pre>
			The <tt>STREAM_DEFINITION</tt> defines a digital input stream that is synchronous with input data.
			If your amplifier/DAC has digital inputs, use such a stream to record them and make them available
			to BCI2000 components through the [[Technical_Reference:State_Definition#State_Concept\|<tt>State</tt>]] interface.

	==ADC Initialization==		==ADC Initialization==

Mellinger: /* ADC Initialization */

2021-10-14T15:47:03Z

ADC Initialization

← Older revision		Revision as of 15:47, 14 October 2021
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	if( TACHYON_NO_ERROR != TachyonStart( Parameter( "SamplingRate" ), Parameter( "SourceCh" ) ) )		if( TACHYON_NO_ERROR != TachyonStart( Parameter( "SamplingRate" ), Parameter( "SourceCh" ) ) )
	bcierr << "SamplingRate and/or SourceCh parameters are not compatible"		bcierr << "SamplingRate and/or SourceCh parameters are not compatible"
	<< " with the A/D card"		<< " with the A/D card";
	~~<< endl~~;
	outputProperties = SignalProperties( Parameter( "SourceCh" ),		outputProperties = SignalProperties( Parameter( "SourceCh" ),
	Parameter( "SampleBlockSize" ),		Parameter( "SampleBlockSize" ),

Mellinger: /* ADC Implementation */

2021-10-14T15:46:29Z

ADC Implementation

← Older revision		Revision as of 15:46, 14 October 2021
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	#include "Tachyon/TachyonLib.h"		#include "Tachyon/TachyonLib.h"
	#include "BCIStream.h"		#include "BCIStream.h"

	~~using namespace std;~~

	RegisterFilter( TachyonADC, 1 );		RegisterFilter( TachyonADC, 1 );