Vertical Sync sensor: Difference between revisions

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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("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 output connector has two binary eight bit ports: input and output. The two ports can be used for responses (input) and stimulus triggers (output). Two 12 bits analog outputs and three 12 bits analog inputs. The output connector has a sound and voicekey which triggers when a amplitude reaches a threshold. By using the serial port, the BITSI can be used platform independently: it works on Windows, Linux and Mac OSX. Most programming environments and stimulus packages support serial communication.
There is currently a [[Microsoft Windows driver issue]].


== BITSI Protocol ==
== BITSI Protocol ==
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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. Because the BITSI is designed to interface both in- and output signals, the 'protocol' is asymmetric: the input and output protocols differ.


===Input===
| 1 || A / a || 65 / 97


The input port can be used to interface eight buttons maximally. Button presses are translated to serial output characters/bytes according to the following table:
{| class="wikitable" 
|-
! scope="row" colspan="3" | BITSI Simple
|-
! scope="row" width="120px" | Signal/Button
! scope="row" width="120px" | ASCII (rise/fall)
! scope="row" width="120px" | Code (rise/fall)
|-
| 1 || A / a || 65 / 97
|-
| 2 || B / b || 66 / 98
|-
| 3 || C / c || 67 / 99
|-
| 4 || D / d || 68 / 100
|-
| 5 || E / e || 69 / 101
|-
| 6 || F / f || 70 / 102
|-
| 7 || G / g || 71 / 103
|-
| 8 || H / h || 72 / 104
|-
|}
|}


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