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Problem with ov2640 + SERDESUB-16OVT

Guillermo Maroto
Prodigy 150 points

Hi TI,

Recently we bought the SERDESUB-16OVT for work with the sensor OV2640.

We’ve followed the all the steps in the User Guide:

Page 4 SERDESUB-16OVT EVM User’s Guide http://www.ti.com/lit/ug/snlu108/snlu108.pdf

pages 21,22 SERDESUB-16USB User’s Guide http://www.ti.com/lit/ug/snlu100/snlu100.pdf

 

4. SETUP INSTRUCTIONS

  1. Connect the DS90UB901Q Serializer board to the Omnivision module via the J1 32-pin header (16 x 2 x 0.1"). Ensure that the camera module and the Serializer board are connected properly by matching the ground (GND) pins. CORRECT
  2. Connect the DS90UB902Q Deserializer board to the Host Controller.  CORRECT
  3. Connect the DS90UB901Q Serializer board to the DS90UB902Q Deserializer board via CAT6 cable on the RJ45 connectors.  CORRECT
  4. Apply 5V power supply to the Deserializer board J10 power jack.  CORRECT
  5. Push “ON” button (S4) on Deserializer board. Green light should now be visible on RJ45 connectors at Serializer (J4) board and Deserializer (J7) board to indicate power is applied to the boards.  CORRECT
  6. Initialize the Deserializer. Refer to the DS90UB901Q/902Q datasheet for startup procedure and the definition of each register.  CORRECT
  7. Verify that LOCK LED on D5 and the RJ45 orange lights are lit. This indicates the chipset is Locked and ready to begin I2C communication with the image sensor.  CORRECT
  8. Initialize the OmniVision image sensor. Refer to the appropriate sensor datasheet for specific information.  CORRECT
  9. Start video capture (or alternate control application). HERE IS THE PROBLEM: When I start the sensor the LOCK led goes from HIGH level to blink.

 

I tried to take a photo with OV2640 and doesn’t work. I can observe the led LOCK is blinking like the capture attached.

 LOCK_blinking.JPG

 

This is my PCLK from the sensor OV2640

 

This is my PCLK again with DATA0

PCLKfromOV2640_data0.JPG

 

I’ve connected HREF, VSYNC, PCLK, D9-D2 as in the table.

901

OV2640

HREF

HSYNC

VSYNC

VSYNC

PCLK

PCLK

D9-D2 (D1,D0 to GND)

D9-D2

SDA

SDA

SCL

SCL

Also the correct powers , RESET and PWDN.


What are we doing wrong? 

Thanks for your answer.

 

Datasheet OV2640 

  • 0
    TI__Genius 14015 points

    Hi Guillermo,

    Can you measure the jitter on the PCLK coming from the OV2640? The sensor datasheet doesn't give a spec. Also, you can check register 0x0C bit 2, PCLK Detect, to see if the 901 is seeing a valid PCLK. Since it seems like the problem is intermittent, you can try reading that register repeatedly and make sure that it is consistently good. 

    Thanks,
    Jason Blackman

  • 0
    Prodigy 150 points

    Here you have more pictures describing the problem:

    Yellow: D0 901 Input  from the sensor OV2640

    Blue: D0 902 Output 

    The serdes starts working but suddenly it doesn't work.

    Any help with that? We are trying to measure the Jitter since we have never done it, we'll see if we can do it.

  • 0 in reply to Jason Blackman
    Prodigy 150 points

    Hi Jason,

    This is the Period Jitter of PCLK from the sensor

  • 0 in reply to Guillermo Maroto
    Prodigy 40 points

    Hi Guillermo,

    right now, I'm trying start up the camera OV2640, but  the camera doesn't work.

    I don't know if it's a power problem, if the camera is damage or if I'm missing something in the initialization of the camera.

    Voltage power suppy:

           AVDD =3V

           DVDD=1.3V

           DOVDD=3V

    AVDD and D0VDD are separated by R/C filter, as shown in "OV2640 Camera Module Hardware Application Notes".

    SCCB bus =1,8V

    XCLK=24MHz external oscillator.

    Initialization on OV2640:

         XCLK=active

          PWDR=low

         RESET=high

         SCCB_CLK=high

         SCCB_DATA=high

    After initialization, PCLK should be running, and HREF,VSYNC AND d[9:0] generate output, but that didn't happen.

    I also tried to read and write registers of the camera and it has been impossible.

    Could someone tell me if I'm doing something wrong or if the camera is damage. 
    The test I have done with several cameras.

    Thanks,

    Diana.