Due to the U.S. Thanksgiving holiday, please expect delayed responses during the week of 11/22.

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TIDA-00554: Failed to obtain normal spectrum data

Part Number: TIDA-00554

Dear TI support team:

We failed to obtain normal spectrum data,as shown in the figure. What could be the problem? And how to deal with it?

Look forward to your reply.

  • Hello Qinqin,

    Welcome to DLP forum and thank you for your interest in DLP technology.

    Thank you for sharing the screen shot of the GUI. Could you please take the measure again with following setting and upload the CSV file for each scan. This will help us understand the issue.

    1. Test 1 - Same as screen shot you shared

    2.  Test - Change the PGA gain to 1 in the above case.

    3. Test 3 - Scan with Column scan (not Hadamard) and PGA gain 1.

    Please upload the CSB files for above three test cases.

    Thanks and regards,

    Vivek

  • Dear Vivek,

    Thanks for your reply.

    We have taken the measure again with setting described above and uploaded the CSV files for above three test cases, please refer to the attached files.

    Regards

    Qinqin

    test data.zip

  • Hello Qinqin,

    Thank you for this data. Please give us a few days to review and we will post back.

    Regards,

    Arthur

  • Hello Qinqin,

    Thank you for uploading the CSV files. It  does confirm that captured data is abnormal. Could you please let us know what material your are scanning?

    Please confirm that you are using it as reflecting scan and sample is placed on window. It is tightly secured, there is no gap or movement while scanning.

    Please push the PCBs to ensure that there is no loose connection , both PCBS are tightly secured and no loose contact in the connectors.

    Please take measure with two different types of samples under with following settings:

    1. Test condition 1

        Scan configuration - Column

       Number of scans to average - 6

       Scan Reference select - Factory

      back to back scan - 1

    2. Test condition 2 

    Scan configuration - Column

       Number of scans to average - 1

       Scan Reference select - Factory

      Back to back scan - 6

    Test second test will generate 6 CSV files.  Please upload scanned CSV file.  This will help me understand if there is an hardware issue.

    regards,

    Vivek

  • Hello Vivek, 

    Thank you for your reply. It has confused us a lot that we could not obtain normal data. We use poly tetra fluoroethylene(PTEF) as scanning material, which is usually used as a diffuse reflection standard whiteboard.

    We do confirm that we are using it as reflecting scan and sample is placed on window. It is tightly secured, there is no gap or movement while scanning.

    We have checked the PCBs to ensure that there is no loose connection , both PCBS are tightly secured and no loose contact in the connectors.

    We have taken measure with two different types of samples according to the setting requirements.

    We uploaded 3 CSV files under test condition 1 setting. Because we found that the data was always different in each measurement. Test second test generated 6 CSV files. All CSV files were uploaded as attachments.

    test data-2.zip

    Regards

    Qinqin

  • Qinqin,

    Thanks for elaborating. The team will need a couple of days (should not be more than a week) to get back to you. Thanks ahead for your patience.

    Regards,

    Philippe

  • Hello Qinqin,

    Thank you for uploading the CSV files. From experiment 2, I do notice that lamp intensity is changing from scan to scan.  Please note that intensity values are negative in many places. I believe that the values had an overflow (signal saturation) due to 16 PGA gain.

    Could you please rerun the experiment with following test conidiations:

    Note : please make sue that you select PGA gain to 1 for all tests, please don't leave them at  auto.

    1. Test condition 1 

             Scan configuration - Column

            Number of scans to average - 1

            Scan Reference select - Factory

            PGA Gain - 1

           Back to back scan - 6

    2. Test condition 2

             Scan configuration - Column

            Number of scans to average - 1

            Scan Reference select - Factory

            Keep Lamp on Box - Checked

            PGA Gain - 1

           Back to back scan - 6

    These two tests will help us understand if the variation is at power up and happens even when Lamp is continuously on between scans.

    In case you have another working unit then please swap the illumination head /module.  See issue follows the base EVM or illumination head.  This will help us identify the problem is with lamp or driver circuit.

    regards,

    Vivek

  • Hello Vivek,

    Thank you for your follow-ups.

    Yes, we have noted that the intensity values are negative in many places. Even we rerun the experiment with the above test conditions (test data: 7266.test data3.rar), the spectral intensity is still negative in the range of about 900-1300 nm.

    In the new test experiments, we make sure that we select PGA gain to 1 for all tests and never leave them at auto.

    In addition, we replaced the illumination module and performed the above two sets of experiments. The illumination module has a single 5V 1.4W bulb, which also includes light feedback. The test data based on the new illumination module is in the folder "new one lamp illumination module (5V 1.4W)". However, there is no significant difference between the two measurements, for the data is still abnormal.

    So, can it be concluded that the problem is not with lamp or drive circuit? And what is the most likely problem to be?

    Regards,

    Qinqin

  • Qinqin,

    You mentioned that you replaced the illumination module. Does that mean you have a second device available? If so, have you tried testing that one with the same exercise to see if it has the same problem?

    Regards,

    Philippe

  • Hi Phillippe,

    We do have a second device available. Since the EVM module is not available, we have purchased another new development kit this month, which test data is normal. However, what we replaced is not  illumination module of the new development kit, but the  illumination module developed according to the design drawing downloaded from the official website. 

    Regards,

    Qinqin

  • Hello Qinqin,

    Could you please upload the files as zip not rar?

    regards,

    Vivek

  • Hello Vivek,

    Here are the zip files.test data3.zip

    Regards,

    Qinqin

  • Hello Qinqin,

    Thank for these files we will review and get back to you in a couple days.

    Regards,

    Arthur

  • Hello Qinqin,

    These seems to a hardware related issues. The ADC output is saturated and it is giving negative value. Did you make any changes or modified system?

    Please try carefully taking out the both boarded and assembling back.  Please also check that pins in the connector are OK especially check if any  pin is bent or  shorted.

    regards,

    Vivek