2 Replies Latest reply on Oct 31, 2018 1:52 AM by migac_3647931

    uncover the sensor will mess up the stream

      I just encounter a weird phenomenon---uncovering the sensor will cause backflow and make streaming stuck

       

      I am now working on FX3 + Aptina sensor, using AN75779 based code. The output window is 1280*760, 2 bytes per pixel, 30 fps, so the frame size is 1280*960*2 = 2457600, since DMA buffer is 16384-12=16368, so for each frame, total 2457600/16368 = 150 full buffers are captured and reported in CyFxUvcApplnDmaCallback, plus 2400 bytes partial buffer.

      When this FX3+sensor is plugged to the host(NOTE: covering the sensor with a card, or anything not transparent). viewed from the serial console, it just shows the exact number described above, and continous video shows in Amcap, seems everything work fine.

       

      removing the cover, however, the streaming stops immediatly, and I also  find full/partial buffer is not as expected, that is why the streaming got stuck.

       

      I presume it's probably related to sensor exposure, but even if I turn on/off sensor AEC(auto exposure control), it's always this case.

       

      can anyone explain why uncovering the sensor can cause this error?

       

      消息编辑者为:michael gao