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DLPNIRNANOEVM: About DLPNIRNANOEVM without using built-in lamp

Part Number: DLPNIRNANOEVM

Hi

I have a question about DLPNIRNANOEVM.

I would like to use the EVM without built-in lamp.

Is there a use mode that turns off the built-in lamp and measures light from the outside as it is?

If there is a good way, please let me know.

Best Regards,

Leonardo

  • Hi Leonardo,

    Are you planning on leaving the reflectance head on the lamp and you would just like to disable the lamp? What I would recommend is that you just unplug the connector with the black/red wires, which is lamp power.

    To measure the light from the outside, you might be able to use the photo detector in the reflectance head as a proxy, but I don't think very much ambient light reaches it, as it is really designed to measure the output from one of the lamps. You may want to look into attaching some sort of external photo detector to the system.

    On your Nano, find the blue/white wires leading from the reflectance head. Those wires and its associated connector are for the photo detector. You could use that connector to drive an external photo detector instead of the internal one. I would look at the BOM for the Nano and order a copy of the photo detector used for the lamps.

    All the design documents for the Nano can be found here: www.ti.com/.../tida-00554

    Let me know if you have any further questions!
    -Paul
  • Hi Paul,

    Thank you for your support always.

    I could understand to disable the lamp.
    I would like to unplug the connector with the black/red wires.

    Thank you for advice on how to measure light from the outside.

    The photo detector in the reflectance head is connected to SENS of DLPA 2005, is not it?

    What is the role and function of this detector?

    Best Regards,
    Leonardo

  • Hi Leonardo,

    The function/purpose of the photo detector is to give the system some indication of what the lamp intensity is. One could imagine scenarios where it would be useful to program a warm-up time which is dependent on that detector reaching a certain value.

    -Paul
  • When I unplug the lamp connector, I get an ADC data error, and am unable to perform any scans. Could you suggest what I might have missed?
    Thanks.
  • Hi Sam,

    Are you sure you've unplugged the lamp connector? The lamp connector should just have black and red wires in it and it should be close to the optical head of the Nano. It is an 8 pin connector and not all of the pins are used.

    If you disconnected the larger connector which has black/red wires and all the pins in the connector filed, you've disconnected the detector from the system, which will cause it to not work.

    Make sure that all the connectors are seated properly and that you're using a high quality USB cable. These can sometimes cause issues as well.

    Best,

    Paul

  • I am certain I have disconnected the correct connector.

    It is the plug with two red, and two black wires, on an 8 pin connector as you describe.

    After some troubleshooting, this error seems to only appear when the PGA Gain is set to Auto.

    When I change the PGA Gain to 64, or any other number, no error dialog box appears.

  • Hi Sam,

    Are you using the latest version of the FW/SW/GUI? Are all the connectors fully seated?

    -Paul
  • Hi Paul

    Yes, all connectors are firmly in place.
    Tiva SW version 2.1.0
    GUI version 2.1.0
    DLPC Flash Version 2.0.0
  • Hi Sam,

    Glad you're using the latest software. The last easy thing to check is the USB cable. Do you have a shorter one you can try? We've done extensive testing on the Nano without the reflectance head plugged in and have never had an issue. In fact, part of the calibration procedure in the factory involves removing the reflectance head. Usually these ADC errors pop up when connectors are not seated or if there is some communication issue with the PC.

    Have you made any modifications to your Nano? Have you ever disassembled it? Sometimes the board to board connectors can be improperly seated as well.

    It is strange that you only see the error on "auto" gain setting. Perhaps it would be worth reloading all the SW/FW pieces just in case something got corrupted.

    Best,
    Paul
  • Hi Paul

    I have tested the connection with 3 different USB cables. I have also reloaded the SW/FW.

    I had initial success with scans without the reflective head, but after a short while, the errors reappeared.

    In addition, the error dialog box shows "scan or reference data interpret failed". I could not find anything like this in the user manual.

    Sam

  • According to the manual, when PGA gain is set to 'Auto' it does a scan to determine the highest gain possible, without overflow.
    Is it possible that dim lighting could produce the error, when attempting to determine this gain?
  • Yes, that is possible. Can you describe what you are scanning and attach some example CSV files?

    -Paul