User Reference:gMOBIlabPlusADC: Difference between revisions

Revision as of 18:31, 10 March 2009

Function

The gMOBIlabPlusADC acquires data from a g.MOBIlab+ device. The g.MOBIlab+ is an amplifier/digitizer combination from g.tec medical engineering GmbH/Guger Technologies OEG (http://www.gtec.at) which can transmit data wirelessly via a Bluetooth connection.

g.MOBIlab Hardware

The MOBIlab device supports 8 analog input channels digitized at 16 bit resolution and sampled at a fixed 256 Hz sampling rate. Additionally, 8 digital input lines can be sampled with the analog data, so that behavioral information (e.g., button presses) can be recorded as well. The amplifier has a sensitivity of $\pm 500 μ V$ ,

This device only has one A/D converter and thus samples are digitized at slightly different times. BCI2000 has a feature that can align samples in time (parameter AlignChannels, which needs to be turned on (i.e., AlignChannels needs to be 1).

An additional feature of the MOBIlab+ is 4 digital input lines, and 4 digital input/output lines. The MOBIlab source module is configured such that channels 9-16 corresponds to the value of the digital lines, which are configured as input lines.

Installation

Prior to using the g.MOBIlab+, the bluetooth software must be installed, and the serial port configured to connect to the device. The instructions can be found in this PDF.

Parameters

COMport

Serial port of the attached MOBIlab device, e.g., COM2:

SampleBlockSize

Samples per digitized block. A value of 8 corresponds to a BCI2000 system rate of 32 Hz ( $\frac{8 s a m p l e s}{256 H z}$ ).

SamplingRate

The sampling rate of the MOBIlab. This value has to be 256.

SourceCh

The total number of channels. This number can be 1 to 9. If it is set to 9, then channels 1-8 represent 8 analog input channels, and channel 9 represents the values of the two digital lines.

States

None.

@@ Line 5: / Line 5: @@
 ===g.MOBIlab Hardware===
 The MOBIlab device supports 8 analog input channels digitized at 16 bit
-resolution and sampled at a fixed 256 Hz sampling rate. In its standard
+resolution and sampled at a fixed 256 Hz sampling rate. Additionally, 8 digital input lines can be sampled with the analog data, so that behavioral information (e.g., button presses) can be recorded as well. The amplifier has a sensitivity of  <math>\pm500\mu V</math>,
-configuration, channels 1-2 have a sensitivity of <math>\pm100\mu V</math>, channels 3-4
-have a sensitivity of <math>\pm500\mu V</math>, channels 5-6 have a sensitivity of
-<math>\pm5mV</math>, and channels 7-8 have a sensitivity of <math>\pm5V</math>.
-The input range of the A/D converter is approximately equal to this sensitivity and thus, for example,
-one LSB for channel 1 or 2 is roughly <math>\frac{200\mu V}{65536}=0.003\mu V</math>.
-However, the actual input range of the A/D converter is slightly larger than the sensitivity
-of each channel (so that the A/D converter can detect when the amp saturates), and
-thus, exact LSB values have to be determined for each channel using a calibration signal.
 This device only has one A/D converter and thus samples are digitized at slightly different times. BCI2000 has a feature that can align samples in time (parameter [[User Reference:AlignmentFilter#AlignChannels|AlignChannels]], which needs to be turned on (i.e., ''AlignChannels'' needs to be 1).
-An additional feature of the MOBIlab is 2 digital input/output lines. The MOBIlab source module is configured such that channel 9 corresponds to the value of the digital lines,
+An additional feature of the MOBIlab+ is 4 digital input lines, and 4 digital input/output lines. The MOBIlab source module is configured such that channels 9-16 corresponds to the value of the digital lines, which are configured as input lines.
-which are configured as input lines.
+==Installation==
+Prior to using the g.MOBIlab+, the bluetooth software must be installed, and the serial port configured to connect to the device. The instructions can be found in this PDF.
 ==Parameters==