FX3 UVC - How to define the EXPOSURE TIME

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HuYa_4249091
Level 4
Level 4
25 replies posted 25 sign-ins 10 replies posted

Hi All:

I referred the AN75779 document to achieve the UVC device, and it works!

However, I met a trouble to define the Camera Terminal - Exposure Time (Absolute) Control.

I don’t know how to define that... It’s more difficult than the Processing Unit, such as Brightness Control.

I also refer the “USB Device Class Definition for Video Devices v1.5.pdf” for the control function, but it don’t describe the rule detailed.

Now I just know the Exposure Time (Absolute) Control is defined by “2 to the power of n”, and the resolution(one step) is to change the “n”.

[Goat]

Total Step: 10(-10 ~ -1)

Max value: 1024

Min value: 1

Default value: 256

[My Setting]

code1.jpg

code2-2.jpg

[My Result]

It’s strange... (Checked the actual setting value by UART)

max value2.jpg

The slider range: -13 ~ -3

Max value: 1024

Min value: 1

Each step value

data.jpg

Hope somebody could provide me some suggestions, or provide an example by my [Goat].

Thank you so much!

Hughes

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1 Solution

hello,

Windows using log2() second to get/set exposure time.

Your max/min value (4/2) means 0.4ms and 0.2ms,

and

log2(0.0004) = -11.28771,

log2(0.0002) = -12.28771.

so the result is -11 and -12.

KSPROPERTY\_CAMERACONTROL\_EXPOSURE - Windows drivers | Microsoft Docs

Hope this helps.

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