DLP6500FYE: Issues with setting exposure of DLP LC 6500

Art Mecina

Part Number: DLP6500FYE
Other Parts Discussed in Thread: DLPC900

Hello Guys,

Good day.

Our customer is using the DLP LC 6500 in conjunction with a camera acquire images of various phantoms. The issue he'd been running into is that he can't seem to set the projector exposure above 11 seconds. At 11 seconds, the projector's exposure is fine, at 12 seconds it is around 1 second, at 15 seconds it is about 4 seconds, and when set at 90 seconds, the exposure seen is around 7 seconds. He was wondering why this issue was arising.

He was just observing the projector sequence that he input. In the attachment, his exposure is set to 20 seconds, but when he saw the projector sequence, it's only projecting each image for around 4 seconds.

Thanks and regards,

Art

over 2 years ago

0 SHIVAKUMAR R over 2 years ago

TI__Expert 3020 points

Hi Art,

Referring to DLPC900 programmers' guide https://www.ti.com/lit/pdf/dlpu018, "Table 2-137. Pattern Display LUT Definition Command Definition", Pattern exposure and dark display time data length is maximum 24 bits

0xFFFFFF = 16777215. Maximum exposure and dark time acceptable by system is limited to 16777215 micro seconds.

Ideally, exposure time till this value should work. Let me check if there is any limitation in the firmware for it to work only till 11seconds.

Thanks,
Shivakumar.

0 Art Mecina over 2 years ago in reply to SHIVAKUMAR R

TI__Genius 16505 points

Thanks for looking into this Shivakumar. Let me know once you found additional info.

Best regards,

Art

0 Art Mecina over 2 years ago in reply to Art Mecina

TI__Genius 16505 points

Hello Shivakumar,

Did you find additional information on the limitation in the firmware for it to work only till 11seconds?

Thanks and regards,

Art

0 Aaron Black over 2 years ago in reply to Art Mecina

TI__Expert 4960 points

Hello Art,

India has a holiday today. Next week we get back to you on what is causing this limitation.

Best,

Aaron

0 Art Mecina over 2 years ago in reply to Aaron Black

TI__Genius 16505 points

Hello Guys,

Good day.

Just like to update regarding this request.

Thanks and regards,

Art

0 SHIVAKUMAR R over 2 years ago in reply to Art Mecina

TI__Expert 3020 points

Hi Art,

It would take some more time to check the firmware.
I will share update on this by Wednesday. Till then customer can consider 11sec as the maximum exposure time supported and develop there application.

Thanks,
Shivakumar

0 SHIVAKUMAR R over 2 years ago in reply to SHIVAKUMAR R

TI__Expert 3020 points

Hi Art,

It looks like due to the internal type conversion, value greater than 11seconds is not converted properly for exposure time internal calculation.

This issue will be fixed in next firmware release and maximum exposure/dark time of 16777215 micro seconds will be working.

Thanks,
Shivakumar.

0 Art Mecina over 2 years ago in reply to SHIVAKUMAR R

TI__Genius 16505 points

Thanks Shivakumar.

Do you know when the next firmware release will be?

Best regards,

Art

0 SHIVAKUMAR R over 2 years ago in reply to Art Mecina

TI__Expert 3020 points

Hi Art,

Next firmware release may be in 1Q 2022.

Thanks,
Shivakumar

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DLP6500FYE: Issues with setting exposure of DLP LC 6500