Difference between revisions of "Vertical Sync sensor"

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{{Infobox tsg
 
{{Infobox tsg
−
| name          = Buttonbox (2018)
+
| name          = Vertical Sync sensor
−
| image          = Buttonbox_2018_1.png
+
| image          = sensorPic.jpg
−
| caption        = 2018 Buttonbox
+
| caption        = Vertical Sync sensor
 +
}}
 +
{{Infobox tsg
 +
| name          = Seeed Studio XIAO SAMD21
 +
| image          = Seeeduino_XIAO.JPG
 +
| caption        = Seeed Studio XIAO SAMD21
 +
| downloads      = {{bulleted list
 +
      | [https://wiki.seeedstudio.com/Seeeduino-XIAO/ product_page]
 +
  }}
 +
}}
 +
{{Infobox tsg
 +
| name          = TEMT6000 Licht Sensor Module
 +
| image          = temt6000.jpg
 +
| caption        = TEMT6000 Licht Sensor Module
 
| downloads      = {{bulleted list
 
| downloads      = {{bulleted list
−
       | [https://surfdrive.surf.nl/files/index.php/s/PPTKCyrjLkN4XUO Buttonbox 2018]
+
       | [https://surfdrive.surf.nl/files/index.php/s/Mpdr2DGEFlwetag Datasheet]
−
      | [https://pypi.python.org/pypi/RuSocSci RuSocSci] (Python package)
 
 
   }}
 
   }}
 
}}
 
}}
  
−
The Vertical Sync sensor is used on a computer/laptop monitor for time accurate visual presentation. The sensor measures screen brightness. It generates a BITSI trigger("A" = ON/light, "a" = OFF/noLight) when the amount of light is higher than the (customizable) threshold, which means that the exact onset of any visual stimulus can be marked. It can easily be attached to any screen with a pincher. The Vertical Sync sensor is connected to a computer with a usb connection.
+
The Vertical Sync sensor is used on a computer/laptop monitor for time accurate visual presentation. The sensor measures screen brightness. It generates a BITSI trigger to the com-port("A" = ON/light, "a" = OFF/noLight) when the amount of light is higher than the (customizable) threshold. This means that the onset of visual stimulus on screen can be marked. It can easily be attached with a pincher to the screen. The Vertical Sync sensor is connected to a computer with a usb connection, a serial port is emulated. You may want to read about [[presentation modes]] in order to decide how to use the sync sensor.
  
 
== BITSI Protocol ==
 
== BITSI Protocol ==
  
−
BITSI stands for Bits to Serial Interface. Because the BITSI is designed to interface both in- and output signals, the 'protocol' is asymmetric: the input and output protocols differ.
+
BITSI stands for Bits to Serial Interface.
−
{|-
 
−
| 1 || A / a || 65 / 97 || ON / OFF
 
−
|-
 
−
|}
 
−
 
 
−
This means that when signal 1 gets active(button press), a capital A will be sent to the serial port. A lowercase 'a' will be sent when the signal is deactivated(button release). Mechanical buttons can be connected directly.
 
−
 
 
−
===Output===
 
−
 
 
−
Output knows two protocols: '''BITSI simple''' or '''BITSI extended'''. To enter a certain protocol two buttons have to be pressed when the BITSIbox is powered or com port opens. '''[2015]Press button H and A for simple mode and H and B for extended mode. [2018]Press button E and A for simple mode and E and B for extended mode.'''
 
−
 
 
−
If no button is pressed when powered it boots the last known protocol. In the simple protocol every byte sent to the BITSI over the serial port, is represented at the 8 bit output.
 
−
 
 
−
The '''extended''' protocol uses two bytes(or two characters), this combination can access two analog outputs and a tone generator. The first byte selects the output. The second byte determines the value written to this output.
 
−
 
 
 
{| class="wikitable"   
 
{| class="wikitable"   
 
|-  
 
|-  
−
! scope="row" colspan="3" | BITSI Extended
+
! scope="row" colspan="3" | Vertical Sync sensor
 
|-
 
|-
−
! scope="row" width="120px" | Function
+
! scope="row" width="120px" | ASCII (rise/fall)
−
! scope="row" width="150px" | Byte 1 (ASCII/code)
+
! scope="row" width="120px" | Code (rise/fall)
−
! scope="row" width="150px" | Byte 2
+
! scope="row" width="120px" | Light
 
|-
 
|-
−
| Marker Out || M / 77 || Marker Value
+
| A / a || 65 / 97 || ON / OFF
−
|-
 
−
| Pulse Out || P / 80 || Marker Value
 
−
|-
 
−
| Pulse Time || X / 88 || ms before pulse reset
 
−
|-
 
−
| Analog Out 1 || Y / 89 || Analog Output Value
 
−
|-
 
−
| Analog Out 2 || Z / 90 || Analog Output Value
 
−
|-
 
−
| Tone || T / 84 || Start Tone
 
−
|-
 
−
| Detect Sound || D / || S / 83
 
−
|-
 
−
| Detect Voice || D / || V / 83
 
−
|-
 
−
| Calibrate Sound || C / || S
 
−
|-
 
−
| Calibrate Voice || C / || V
 
−
|-
 
−
| Analog In 1 || A / || 1
 
−
|-
 
−
| Analog In 2 || A / || 2
 
−
|-
 
−
| Analog In 3 || A / || 3
 
−
|-
 
−
| Analog In 4 || A / || 4
 
−
|-
 
−
| LEDs Off || L / || X
 
−
|-
 
−
| LEDs Input || L / || I
 
−
|-
 
−
| LEDs Output || L / || O
 
 
|-
 
|-
 
|}
 
|}
  
−
== Port Settings ==
+
Meaning when light falls on the sensor, a capital A will be sent to the serial port. A lowercase 'a' will be sent when the signal is deactivated(no light).
  
−
===Trigger port ===
+
===Output===
  
−
[[File:Connector.png|thumb|300x300px|Schematic view of the 25 pins connector]]
+
The treshold for monitor OFF is customizable and can be specified by sending a byte to specify the value for screen OFF. Any byte satisfies, see example code.
  
−
The 25 pins female connector has 8 inputs and 8 outputs, respectively 1-8 are inputs and 9-16 are outputs. Three analog input with an analog to digital convertor of 12 bit, pins 17,18,20 and 21. Two analog outputs with an digital to analog convertor of 12 bits on pins 22 and 23.
+
== Port Settings ==
−
 
 
−
The inputs 1-8 will be pulled down from 5V to GND when the buttons are pressed. The outputs 9-16 will be pulled up from GND to 5V when the output is activated.
 
  
 
===Serial port===
 
===Serial port===
Line 103: Line 66:
 
=== USB-Com port ===
 
=== USB-Com port ===
  
−
1.Connect the BITSIbox to your computer using the USB cable.
+
1.Connect the Vertical Sync sensor to your computer using the USB cable.
  
−
2.When you connect the BITSIbox, Windows should initiate the driver installation process (if you haven't used the computer with an BITSIbox board before).
+
2.When you connect the Vertical Sync sensor, Windows should initiate the driver installation process (if you haven't used the computer with an Vertical Sync sensor before).
−
 
 
−
3.On Windows Vista/7, the driver should be automatically downloaded and installed.
 
−
 
 
−
4.On Windows XP, the Add New Hardware wizard will open:
 
−
 
 
−
*When asked '''Can Windows connect to Windows Update to search for software?''' select '''No, not this time'''. Click next.
 
−
*Select '''Install from a list or specified location (Advanced)''' and click next.
 
−
*Make sure that '''Search for the best driver in these locations''' is checked; uncheck '''Search removable media'''; check '''Include this location in the search''' and browse to the '''c:/beheer/arduino/drivers '''directory.
 
−
*The wizard will search for the driver and then tell you that a "USB Serial Converter" was found. Click finish.
 
−
*The new hardware wizard will appear again. Go through the same steps and select the same options and location to search. This time, a "USB Serial Port" will be found.
 
  
 
'''How to Check the Com Port settings(important!)'''
 
'''How to Check the Com Port settings(important!)'''
Line 138: Line 91:
  
 
== Software Settings ==
 
== Software Settings ==
−
 
−
=== Neurobs Presentation ===
 
−
 
−
The experiment files needs a few settings for the device to work:
 
−
* In the settings tab:  port -> input port -> 1 must be the device that identifies itself as "Arduino Uno" in the device manager. Note that the port must have a number not higher than 10 (COM1-COM10). Use re-enumerate if it is higher.
 
−
* Rate must be set 115200, Parity to None, Data Bits to 8 and Stop Bits to 1, Uncheck FIFO Interrupt.
 
−
 
−
[[File:Buttonbox2.png]]
 
−
 
−
'''Testing Buttonbox'''
 
−
 
−
When pressing on the A button within the input channel tester. You will see the following ASCII code.
 
−
 
−
[[file:testbuttonbox.png]]
 
−
 
−
'''Adding Marker'''
 
−
 
−
[[file:output_buttonbox1.png | 800px]]
 
−
 
−
'''Testing Markers (output)'''
 
−
 
−
Send code 1 for Button A
 
−
 
−
[[file:output_buttonbox2.png]]
 
−
 
−
Button A will light up.
 
−
 
−
[[file:buttonboxledA.png | 200px]]
 
−
 
−
Send code 0 for clearing.
 
−
 
−
[[file:output_buttonbox3.png]]
 
−
 
−
'''Example PCL code you can program a handle to send a marker:'''
 
−
 
−
#handle:
 
−
output_port OutputPort = output_port_manager.get_port( 1 );
 
−
 
−
'''Example to send a marker:'''
 
−
OutputPort.send_code(100); #create a marker
 
−
 
−
 
−
for more information see chapter 8 in the presentation course by clicking [http://tsgdoc.socsci.ru.nl/images/9/9e/Programming_with_Presentation_2013.pdf here]
 
  
 
=== Python/PsychoPy ===
 
=== Python/PsychoPy ===
  
−
Download this site-package to use the buttonbox: [https://pypi.python.org/pypi/RuSocSci rusocsci]
+
<br/>'''The basics using the Vertical Sync sensor in PsychoPy:'''
−
 
 
−
or use in windows command 'pip install --upgrade rusocsci'
 
−
 
 
−
'''Example using buttons from the buttonbox in Python:'''
 
  
 
<syntaxhighlight lang="python" line>
 
<syntaxhighlight lang="python" line>
−
#!/usr/bin/env python
+
# initialize treshold for OFF by sending a code
 +
ser.write(b'1')
  
−
# import the rusocsci.buttonbox module
+
visual.Rect(win, .15, .25, pos=(-1, 1),fillColor="white", units="norm").draw()
−
from rusocsci import buttonbox
+
win.flip()
−
 
+
# wait for a sync square
−
# make a buttonbox
+
b = ser.read()
−
bb = buttonbox.Buttonbox()
 
−
 
 
−
# wait for a single button press
 
−
b = bb.waitButtons()
 
−
 
 
−
# print the button pressed
 
−
print("b: {}".format(b))
 
−
</syntaxhighlight>
 
−
 
 
−
'''Example using markers with the buttonbox in Python:'''
 
−
 
 
−
<syntaxhighlight lang="python" line>
 
−
#!/usr/bin/env python
 
−
 
 
−
# import the rusocsci.buttonbox module
 
−
from rusocsci import buttonbox
 
−
 
 
−
# make a buttonbox
 
−
bb = buttonbox.Buttonbox()
 
−
 
 
−
# send a marker
 
−
bb.sendMarker(val=100)    #This is your marker code, range code 1-255
 
−
</syntaxhighlight>
 
−
 
 
−
'''Example using BITSI extended in Python:'''
 
−
 
 
−
<syntaxhighlight lang="python" line>
 
−
#!/usr/bin/env python
 
−
 
 
−
# import the rusocsci.buttonbox module
 
−
from rusocsci import buttonbox
 
−
 
 
−
# make a buttonbox
 
−
bb = buttonbox.Buttonbox()
 
−
 
 
−
# select a function
 
−
bb.sendMarker(val=(ord(X)))    #select pulse time
 
−
bb.sendMarker(val=2)          #set time of dureation pulse to 2ms
 
−
 
 
−
bb.sendMarker(val=(ord(M)))    #select marker out
 
−
bb.sendMarker(val=115)           #set marker value 115
 
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
'''Example using BITSI extended analog read in Python:'''
+
<br/>'''Example script using the Vertical Sync sensor in PsychoPy:'''
−
 
 
−
<syntaxhighlight lang="python" line>
 
−
#!/usr/bin/env python
 
−
 
 
−
# import the rusocsci.buttonbox module
 
−
import serial
 
−
 
 
−
# make a buttonbox
 
−
ser = serial.Serial("COM2", 115200, timeout = 0.10 )
 
−
ser = serial.Serial("/dev/ttyUSB0", 115200, timeout = 0.10 )
 
−
 
 
−
while True:
 
−
ser.write('A1')
 
−
ser.flush()
 
−
x = ser.readline()
 
−
visual.TextStim(win, text=x).draw()
 
−
 
 
−
# black screen for 1000 ms
 
−
win.flip()
 
−
 
 
−
key = event.getKeys()
 
−
try:
 
−
if key[0]=='escape':
 
−
break
 
−
except:
 
−
continue
 
−
</syntaxhighlight>
 
−
 
 
−
<br/>'''Example using the Buttonbox in PsychoPy:'''
 
  
 
<syntaxhighlight lang="python" line>
 
<syntaxhighlight lang="python" line>
Line 276: Line 113:
 
# import psychopy and rusocsci
 
# import psychopy and rusocsci
 
from psychopy import core, visual  
 
from psychopy import core, visual  
−
from rusocsci import buttonbox
+
import serial
 +
import time
  
 
## Setup Section
 
## Setup Section
−
win = visual.Window(monitor="testMonitor")
+
win = visual.Window([400,400], fullscr=True, winType = "pyglet", monitor="testMonitor",color=(-1, -1, -1), waitBlanking=True)
−
bb = buttonbox.Buttonbox()
+
# connect to Vertical Sync sensor, find correct com port number
−
text = visual.TextStim(win, "Press a button on the buttonbox")
+
ser = serial.Serial('com3', 115200, timeout=1.0)
 +
# create sync box left corner
 +
rect = visual.Rect(win, .15, .25, pos=(-1, 1),fillColor="white", units="norm")
 +
 
 +
# wait 5 sec for python to become stabel
 +
core.wait(5)
 +
ser.flushInput()
 +
# define screen OFF by sending a code
 +
ser.write(b'1')
  
 
## Experiment Section
 
## Experiment Section
−
# show text
+
# show sync box left corner
−
text.draw()
+
rect.draw()
−
win.flip()
 
−
# wait for response
 
−
b = bb.waitButtons()
 
−
# show response
 
−
text.setText("you pressed: {}".format(b))
 
−
text.draw()
 
 
win.flip()
 
win.flip()
−
core.wait(5)
+
tik = time.perf_counter()
 +
# wait for a sync square
 +
b = ser.read()
 +
tok = time.perf_counter()
 +
# show delay after a flip
 +
print("your timing after a flip: {}s".format(tok-tik))
 +
# as a remark 60Hz/~0.016s 120Hz/~0.008s
  
 
## Cleanup Section
 
## Cleanup Section
Line 299: Line 145:
 
</syntaxhighlight>
 
</syntaxhighlight>
  
−
For more documentation click here: http://pythonhosted.org//RuSocSci/index.html
 
−
<br>
 
−
<br>
 
 
=== Matlab ===
 
=== Matlab ===
 
'''Example using markers with the Buttonbox in Matlab:'''
 
'''Example using markers with the Buttonbox in Matlab:'''
Line 327: Line 170:
 
% reset marker
 
% reset marker
 
bb.sendTrigger(0)                % Note: if resetting the marker is not possible at this moment in code, you can decide to do this later as long as it has taken place long enough before the next marker has to be sent.
 
bb.sendTrigger(0)                % Note: if resetting the marker is not possible at this moment in code, you can decide to do this later as long as it has taken place long enough before the next marker has to be sent.
−
</syntaxhighlight>
 
−
 
−
BITSI extended mode:
 
−
<syntaxhighlight lang="matlab" line style="overflow:auto;">
 
−
samplerate = 500;
 
−
pulseLen = 2000/samplerate;
 
−
% select a function
 
−
bb.sendTrigger(uint8('X'));  % select pulse time
 
−
bb.sendTrigger(pulseLen);            % set time of duration pulse to (2000/samplerate) ms
 
−
 
−
val = 1;                                    % val: this is your marker code, range code 1-255
 
−
bb.sendTrigger(uint8('M'));  % select marker out
 
−
bb.sendTrigger(val);              % val: this is your marker code, range code 1-255
 
−
</syntaxhighlight>
 
−
 
−
<syntaxhighlight lang="matlab" line style="overflow:auto;">
 
−
% At the end of your script, close the buttonbox serial object
 
−
    :
 
−
bb.close();
 
 
</syntaxhighlight>
 
</syntaxhighlight>

Latest revision as of 11:42, 23 January 2023

Vertical Sync sensor
SensorPic.jpg
Vertical Sync sensor
Seeed Studio XIAO SAMD21
Seeeduino XIAO.JPG
Seeed Studio XIAO SAMD21
Downloads
TEMT6000 Licht Sensor Module
Temt6000.jpg
TEMT6000 Licht Sensor Module
Downloads

The Vertical Sync sensor is used on a computer/laptop monitor for time accurate visual presentation. The sensor measures screen brightness. It generates a BITSI trigger to the com-port("A" = ON/light, "a" = OFF/noLight) when the amount of light is higher than the (customizable) threshold. This means that the onset of visual stimulus on screen can be marked. It can easily be attached with a pincher to the screen. The Vertical Sync sensor is connected to a computer with a usb connection, a serial port is emulated. You may want to read about presentation modes in order to decide how to use the sync sensor.

BITSI Protocol

BITSI stands for Bits to Serial Interface.

Vertical Sync sensor
ASCII (rise/fall) Code (rise/fall) Light
A / a 65 / 97 ON / OFF

Meaning when light falls on the sensor, a capital A will be sent to the serial port. A lowercase 'a' will be sent when the signal is deactivated(no light).

Output

The treshold for monitor OFF is customizable and can be specified by sending a byte to specify the value for screen OFF. Any byte satisfies, see example code.

Port Settings

Serial port

Our hardware design allows to be connected to the computers USB and emulates a serial communication Port.

Baudrate 115200
Parity None
Data bits 8
Stop bits 1
Flow control None

USB-Com port

1.Connect the Vertical Sync sensor to your computer using the USB cable.

2.When you connect the Vertical Sync sensor, Windows should initiate the driver installation process (if you haven't used the computer with an Vertical Sync sensor before).

How to Check the Com Port settings(important!)

  • From the Start menu, open the Control Panel.
  • From the control panel, open the System window.
  • From the system properties window, go to the Hardware tab and click the Device Manager button.
  • From the Device Manager window, click Ports (Com&LPT). You should now be able to see which Com Port the USB adapter is assigned to.
  • If the Com Port is 10 or higher, you will have to change it to a lower port.
  • From the Device Manager window, click on USB Serial Port (Com#). Click the Port Settings tab of the USB Serial Port Properties window, and then click the Advanced button.
  • In the Advanced Settings window, use the scroll input to select a Com Port (select 10 or lower). Change Receive (bytes) and Transmit (bytes) to 64. Change the Latency Timer to 1.
  • Click the OK button.

Always connect the usb device to the same port and your settings will be remembered.

Software Settings

Python/PsychoPy


The basics using the Vertical Sync sensor in PsychoPy: 

1# initialize treshold for OFF by sending a code
2ser.write(b'1')
3
4visual.Rect(win, .15, .25, pos=(-1, 1),fillColor="white", units="norm").draw()
5win.flip()
6# wait for a sync square
7b = ser.read()


Example script using the Vertical Sync sensor in PsychoPy: 

 1#!/usr/bin/env python
 2
 3# import psychopy and rusocsci
 4from psychopy import core, visual 
 5import serial
 6import time
 7
 8## Setup Section
 9win = visual.Window([400,400], fullscr=True, winType = "pyglet", monitor="testMonitor",color=(-1, -1, -1), waitBlanking=True)
10# connect to Vertical Sync sensor, find correct com port number
11ser = serial.Serial('com3', 115200, timeout=1.0)
12# create sync box left corner
13rect = visual.Rect(win, .15, .25, pos=(-1, 1),fillColor="white", units="norm")
14
15# wait 5 sec for python to become stabel
16core.wait(5)
17ser.flushInput()
18# define screen OFF by sending a code
19ser.write(b'1')
20
21## Experiment Section
22# show sync box left corner
23rect.draw()
24win.flip()
25tik = time.perf_counter()
26# wait for a sync square
27b = ser.read()
28tok = time.perf_counter()
29# show delay after a flip
30print("your timing after a flip: {}s".format(tok-tik))
31# as a remark 60Hz/~0.016s 120Hz/~0.008s
32
33## Cleanup Section
34core.quit()

Matlab

Example using markers with the Buttonbox in Matlab:

Download the file Bitsi.m from the DCCN website: https://intranet.donders.ru.nl/index.php?id=bitsim0
Make sure to have this file in your Matlab path. 

1% At the start of your script, create the buttonbox serial object
2bb = Bitsi("COM2");
3% other code
4        :

BITSI simple mode: 

 1% This example is for an EEG system sampling at 500Hz samplerate.  
 2% at the start of your script, reset marker
 3samplerate = 500;
 4pulseLen = 2000/samplerate;
 5bb.sendTrigger(0);
 6% send a marker
 7val = 1;                                     % val: this is your marker code, range code 1-255
 8bb.sendTrigger(val);
 9java.lang.Thread.sleep(pulseLen);    % wait long enough for the EEG system to capture the trigger, i.e., 2000/samplerate ms
10% reset marker
11bb.sendTrigger(0)                 % Note: if resetting the marker is not possible at this moment in code, you can decide to do this later as long as it has taken place long enough before the next marker has to be sent.
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