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DLPNIRSCANEVM: Aberration corrections on the DMD

Part Number: DLPNIRSCANEVM
Other Parts Discussed in Thread: DLPC3470, DLPC150

Hello Team,

Good day.

My Customer is trying to find the function that is doing the aberration corrections on the DMD, because when are trying to control the DMD alone and produce their own patterns, they noticed that there were aberration corrections as the column scans were "curved". Could you point a direction to us which function is controlling the aberration corrections, and how could disable them? If they disabled the calibration, would the column scan be a straight column line on the DMD?

Regards,

Renan

  • Renan,

    Thanks for your inquiry. The DMD patterns are calibrated in this manner to compenstate for the optical distortion of each individual system. What sort of application are you looking to implement by undoing this sort of calibration?

    Regards,

    Philippe Dollo

  • Hello Philippe,

    Thank you for this response.

    The as of the moment my customer mentioned that there were aberration corrections as the column scans were "curved". I will add other information soonest I got their response.

    Regards,

    Renan

  • Hello Philippe,

    Good day.

    My customer wanted to achieve is to use the DMD to generate different patterns, so they think if they don't disable the calibration, even if they do a column scan that they have in the GUI, the column scans are not straight vertical lines.

    And they also wanted to ask for the column scan that we originally have in the GUI, it first resets to like a chessboard pattern before generating the column scan? Because that is what they are seeing when they are imaging the DMD directly. Can you confirm that? Thank you.

    Regards,

    Renan

  • Renan,

    Yes, it may be the case that a checkerboard pattern may load. The calibration exists in order to facilitate the nirScan Nano as a spectroscopy platform. 

    From your description, it sounds like the kinds of patterns you want to use may be better suited to the DLPC3470 chipset (the DLP2010-LC EVM). Does the customer have a specification that requires them to use the nirScan Nano instead?

    https://www.ti.com/tool/DLP2010EVM-LC

  • Hello Philippe,

    My customer already bought the NIRscanNano, and really hoped that it will produce self-generated pattern. And they are aware that the calibration exists in order to facilitate the NIRscan Nano, but do remember talking to one of our technical support and he said that there was a way to bypass this calibration in the source code.
    And just some basic information, they already found the functions for generating the column scan and hadamard scan, and compiled the source code previously, so that shouldn't be the issue. So they are just hoping a way to disable, or to bypass this calibration in the source code, so that it will produce straight vertical scan patterns during column scan. Thanks.

    So right now they have the NIRscan Nano, what would be the difference between this DLP2010EVM EVM-LC. Can they just upload patterns onto this DLP2010EVM? What would be the pattern's file's format? And what is the chip of the DMD? The same as NIRscan Nano?

    Regards,

    Renan

  • Renan,

    It may be possible to do what you are looking for on the nirScan Nano but it will definitely be harder. Since the nirScan Nano is made as a sort of "all-in-one" Spectroscopy package you would definitely need to modify the source code to try to get the results you want.

    The DLP2010-LC EVM (as well as the DLP3010-LC and DLP4710-LC) have a dedicated light control GUI which lets you configure custom patterns in an intuitive interface to stream internally:

    GUI User's Guide: https://www.ti.com/lit/ug/dlpu074a/dlpu074a.pdf 

    Since the above LC EVMs are made for applications such as 3D Print and 3D Scan they don't have any calibration (in other words the light output is pixel-perfect according to your pattern specifications).

    That being said if you want to try to repurpose the behavior of the nirScan Nano you will probably want to modify the source code directly for the TIVA host processor. You should do that in combination with referring to the DLPC150 Programmer's Guide (https://www.ti.com/lit/ug/dlpu031a/dlpu031a.pdf) for the list of I2C commands you can use to load/set up patterns.

    The source code for the TIVA chip can be found on the nirScan Nano's tool folder: https://www.ti.com/tool/DLPNIRNANOEVM 

    Best Regards,

    Philippe Dollo