• TI Thinks Resolved

Transmit video from multiple camera over a coaxial cable

Expert 6150 points

Replies: 8

Views: 89

Hi Team,

A customer wants to transmit video from multiple camera thru a coaxial cable and is looking for a serializer and deserializer. I understand that the DS90UB960 serializer transmits the images via twisted pair cable. Do we have other devices that meets the customer's requirement?

Regards,

Danilo

  • Hi Danilo, 

    We have many pairings of SER-DES pairs for camera applications. Could you please be more specific about the system level specifics? 

    e.g. : parallel/CSI-2 input/output, max data rate (input and output), GPIO?, how many cameras (input) and how many output ports?, etc. 

    Thanks, 

    Sally 

  • In reply to Sally Cheung95:

    Dear Sally,

    Sorry for the late reply. I switched form my personal account to the University account and encountered some problems. Everything seems to be okay now.

    We are currently working on a project which will most probably have multiple CMOS image sensors (for instance 3 of them) to capture the environment. The user requires to view the frames in real-time on a screen which is located around 10m away from the cameras system (distance might change but should not exceed 30m). We are looking for a solution to transfer the images in real-time from the cameras to the screen over a single coaxial cable.

    The cameras which will be used are CMOS image sensors such as the OVM7690 and the OVM7692. To give you an idea, the OVM7690 is a 640 x 480 image senor wit processor that:

    • Operates at up to 30 frames per second (fps) in VGA resolution
    • Uses digital video port (DVP) parallel output interface
    • Supported output formats: RAW RGB, RGB565, CCIR656 and YCbCr422
    • Image processing functions, including exposure, gamma, white balance, colour saturation and hue control are programmable through SCCB interface

    The OVM7692, and other image sensors that could be considered for this application have similar specifications.

    What solutions do you suggest to 'broadcast' data from multiple cameras to a receiving node (in this case a screen or PC system) over a coaxial cable? 

    Please find attached a simple diagram showing what we are after (a block diagram showing what we require - part numbers are only there as an example and will be changed depending on your advice). Thank you in advance.

    Best regards,

    Brian 

    Junior Electrical Engineer (R&D) (UoM)

  • In reply to Brian Azzopardi:

    Hi Brian, 

    I think you forgot the attachment or it didn't go through. For a DVP camera output, I would suggset DS90UB913Q-Q1. The minimum PCLK is 10 MHz and the pclk you gave me is ~9 MHz. However, the DS90UB913Q-Q1 only supports STP. If you are able to increase the PCLK to 25 MHz, then you can use the DS90UB913A-Q1 which has coax support. These are the serializer reccomendations.  You will need to specify the interface of whatever is connecting to the PC so I can suggest a deserializer. 

    PCLK = tot_horizonal * tot_vertical * fps

  • In reply to Sally Cheung95:

    Hi Sally,

    Yes, I forgot to attach the image, please find it attached.

    Block diagram

    Questions

    Regarding your reply, I have a couple of question to ask please.

    1. To you have solutions for lower cameras with PCLK less than 10MHz?
    2. If we had to use STP instead of COAX as the transmission medium between the cameras board system and the main unit, would the STP solution be more straight forward to implement for a multiple cameras?

    Interface to PC

    Ideally, we would have

    • Composite video/CVBS connectors so that the frames captured by the cameras can be displayed on small screens in real-time
    • USB interface to use software installed on the PC to record the frames received

    Thank you

  • In reply to Brian Azzopardi:

    Hello Brian,

    Is it possible for you to use a hub style device on the deserializer side to take in multiple individual cameras and aggregate into one output port using CSI-2? This is the standard method for multi-sensor systems:

    Example multiple DS90UB913Q-Q1 to DS90UB964-Q1. 10MHz is the lowest PCLK frequency DVP mode we have support for in this type of configuration. 

    Best Regards,

    Casey 

  • In reply to Casey McCrea:

    Dear Casey,

    Sorry for the late reply. Does the suggested solution above require multiple coax/STP lines (one coax able or STP pair for each camera) or am I not understanding well?

    Thank you

  • In reply to Brian Azzopardi:

    Hi Brian, 

    The solution proposed above by Casey would still require 1 STP/coax cable for each camera. You could send all the cameras + 1 cable per device into 1 single deserializer hub. This can aggregate all the cameras into one CSI-2 interface output. If you have a specific need for DVP interface to the processor/FPGA/computer, there is no option to aggerate all the cameras in such a way.

  • In reply to Sally Cheung95:

    Dear Sally,

    Thank you for the information. Will review all options and decide on how to proceed.

    Thanks again for your assistance.