Controlling self-guiding filter wheel?

Discussion in 'Scripting and Programming' started by Jasem Mutlaq, Dec 5, 2014.

  1. Jasem Mutlaq

    Jasem Mutlaq Standard User

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    I'm the developer of INDI SBIG driver and recently one SBIG customer reported an issue with
    SBIG STT-8300 with FW8G Self-Guiding Filter Wheel . While the CCD and CFW can be controlled from INDI, the guide head is not detected. I read the SBIG SDK documentation, but I'm not sure how this case is handled, the CCD capabilities bit indicated no external guide head hardware support.

    Is this treated like a normal guide head? How do we detected if the guide head exists? I guess one way is to check for "G" in the CFW name, but is there a better way?

    I'm using SBIG Universal driver on 64bit Linux.
     
  2. Jan Soldan

    Jan Soldan Cyanogen Customer

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    Hi Jasem,

    I will check functions related to the RGH detection on my Linux machine today. I know, there is a problem
    with this detection on STT/STXL cameras, because those cameras do not contain an internal CCD chip and
    an external one can be used as an internal and/or an external one. This would probably require some firmware
    changes inside the camera.

    I already did a lot of trials on driver's level, but without success. The main problem is, you can take an
    image from RGH even if such a device is not connected. This image is blank, i.e. all pixels' ADU = 0.
    I will check if I can set this bit based on FW8G detection as you proposed. This would be really help.

    I will let you know results.

    Also, my apology, I didn't answer your question you have sent me privately a few days ago.
    We are really very busy last two weeks, solving problem with uploading firmware to ST-4K
    on Win 8 machines.

    Regards,
    Jan
     
  3. Jasem Mutlaq

    Jasem Mutlaq Standard User

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    Hi Jan,

    Thank you for your response! I understand you are very busy, it is OK :)

    Btw, I resolved the issue with debayering in the ST-I color version, it was an issue with the debayer routine. Still, the ST-I is not quite suitable for guiding as the image quality & sensitivity is not as good as other guide cams I have. However, I will try today to eliminate one more variable (focusing) before I report my results on the ST-I Color under raspberry PI.
     
  4. Jan Soldan

    Jan Soldan Cyanogen Customer

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  5. Jan Soldan

    Jan Soldan Cyanogen Customer

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    Jasem,
    based on further tests today, I will have to add a new function to the driver to properly determine whether the CCD Guider (FW8G or RGH) is really connected to STXL or STT cameras.
    Those cameras are internally "similar" to the STX camera which has an internal CCD guider and you can also connect the RGH to it, but the STXL or STT camera has no internal guider,
    so it treats the FW8G or RGH as an internal guider. You can take an image from the STXL/STT's guider even if it is not connected to the camera using the HDMI cable. The image
    form such a "virtual" guider has all its pixels equal to zero, i.e back.
    Jan
     
  6. Jasem Mutlaq

    Jasem Mutlaq Standard User

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    Jan,

    Great, looking forward to testing the new driver. Please make sure to release an armhf version in addition to the 32/64 bits versions :)

    Btw, the current way I determine if there is a guide head is to check # of chips function, which returns the # of chips depending on the model.. is there a more reliable way by utilizing a driver function to know if there is a guide head and whether it is internal or external? Perhaps in one of the GetCCDInfoResults structs?
     
  7. Jan Soldan

    Jan Soldan Cyanogen Customer

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    Jasem,
    I have finally found and tested reliable method which I use to set the bit B2 of capabilitiesBits field in the GetCcdInfo driver function.
    This bit was always set to zero if you used the secondary extended request for _Imaging_ CCD and always set to one for the _Tracking_
    CCD regardless whether or not, the RGH and/or FW8G was connected to the STT or STXL cameras or not.

    Now, if you call driver's CC_GET_CCD_INFO function with the secondary extended request for Imaging CCD, this bit B2 will be set to
    zero as previously, but if you call this function with the CCD_TRACKING value, then this bit will be set to 1 if RGH and/or FW8G is
    physically connected to the camera body, otherwise it will be zero too.

    So, now we can precisely distinquish whether or not an external guider is connected to the STT or STXL cameras. I have tested
    it with the STT-8300 + FW8G which was either connected to the camera via HDMI cable or not. Works as expected. I will add the STXL support
    tomorrow, because it requires a bit different values to be send to this method, which is based on reading values from A/D convertor.
    I have also STX digital board here, so will try it too, unfortunately cannot test it with the STXL yet.

    So, nothing was changes from the user's point of view and no separate function was added to the driver as I supposed yesterday.
    Simply bit B2 of the capabilitiesBits is set only if the remote head is really connected to the camera. So, if application gets a blank image from
    the guider running on STT/STXL cameras, it can check this bit to see if the remote guider is really connected or not.

    So, would like to finish this update during 1-2 days, then will send you version for testing. When ready, I will also post the sample of
    source code, how to properly detect the RGH or FW8G. Till now, I have developed and tested it on Linux ARM (Odroid) machine, but do not suppose
    any changes on Windows.

    Jan
     

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