Choosing the right cpu

Discussion in 'Embedded Systems and Microcontrollers' started by gvi70000, Jun 5, 2011.

  1. gvi70000

    Thread Starter Active Member

    Oct 4, 2009
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    Hello,

    Some time ago i've started to build my own remote control for my DSLR camera and until now i came up with two solutions:
    1. The cheap one http://www.grozeaion.com/electronic...-wired-remote-control-for-digital-camera.html
    2. A Touch Shield Slide http://www.grozeaion.com/electronic.../125-gvi-dslr-rc-with-touch-shield-slide.html

    Now, for my next variant i want to have:
    1. Camera will be controlled by USB;
    2. The remote will receive from camera thumbnails images for preview;
    3. Wireless control : a central unit that will receive data from sensors and will send data to the camera.

    As i am still new to this field i need help in choosing a cpu fast enough to transmit/ receive small images, but in the same time i will need guidance, so the programming and hardware for this cpu must have a support forum.

    Any one can suggest me a micro-controller that can do these things?

    Thank you
     
  2. GetDeviceInfo

    Senior Member

    Jun 7, 2009
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    Not sure I'd be concerned as much on speed, but rather on integration. Are you planning on communicating with PIMA commands to the camera, then you'd probably want USB hosting capabilities. Are you configuring your controller as a device to the PC, than either OTG or seperate controller.

    What is your choosen wireless method and will you be attemping real time thumbnail previewing.

    The act of transmitting USB thumbnail image data from camera to your wireless peripheral could be handled by most micros. The limiting speed will likely be your camera, the USB specification, or wireless method being applied.

    PS; a more descriptive subject title may help solicate a larger knowledge base.
     
  3. gvi70000

    Thread Starter Active Member

    Oct 4, 2009
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    0
    Hi,
    I'll be using PTP camera protocol to communicate with the camera and i was thinking at WiFi connection. The thumbnail preview can be delayed up to two seconds.
     
  4. GetDeviceInfo

    Senior Member

    Jun 7, 2009
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    so then you need hosting capability on the USB side, but again, if you want to connect to a PC, you'll want OTG or a second USB controller for device side. You'll also probably want to select your Wifi and review it's interface. Your micro then simply ports USB packets to/from Wifi, PC USB port, camera. Any controller configuration can then fall into vendors commands.

    Because your simply porting, most USB OTG enabled controllers will perform the task, so the choice I would think is determinant on your exposure and development tools.
     
  5. gvi70000

    Thread Starter Active Member

    Oct 4, 2009
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    My post was no clear from the start, i want the wifii as an option to usb.
    If i use the usb then the host will be the central unit and the slave will be tha camera and sensors.

    The device will be connected to a pc only it is programmed and the wifi connection has to work between the sensors <-> central unit on one side and central unit <-> camera on the other side.
     
  6. GetDeviceInfo

    Senior Member

    Jun 7, 2009
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  7. gvi70000

    Thread Starter Active Member

    Oct 4, 2009
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    In the Block Diagram picture the sensors will be connected to the TR1 by wire.
    TR1 will transform the analog signal (0-5V) in digital and send it to the central unit,
    TR1 will also control the sensors power (On/Off).

    The central unit will receive signals from TR1, process these signals and then send the
    signal to the TR2 (the wireless interface between cental unit and camera). The central
    unit can also receive data via TR2 (thumbnails, camera parameters) and display on a OLED
    screen.

    In wired mode the sensors will be connected directly to the central unit (analog data)
    and via USB with the camera.

    Now i'm thinking to a combined mode:
    1. Central unit <-> sensors wireless + Central unit <-> camera via USB;
    2. Central unit <-> sensors analog connection + Central unit <-> wireless;

    So the central unit MCU must handle data transmition, data processing and
    screen control.
     
  8. blueroomelectronics

    AAC Fanatic!

    Jul 22, 2007
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    Which DSLR camera(s) do you plan to support? USB control will have more latency than direct trigger remotes.
     
  9. gvi70000

    Thread Starter Active Member

    Oct 4, 2009
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    At first Canon and Nikon, but using PTP protocol in theory all cameras should work.
     
  10. blueroomelectronics

    AAC Fanatic!

    Jul 22, 2007
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  11. GetDeviceInfo

    Senior Member

    Jun 7, 2009
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    they'll all work on the image file side, but Canon's lineup may not on the control side. I'm sure the bulk of thier DSLRs do support, but their point and shoots where interrmittent, leaning towards non support. I've implemented PTP on thier older A510/20 with good success. I'm not sure that any of them offered on/off remote, which for me was paramount (game cams). I overcame that with a hardware hack, tying the off/on switch to the unused USB pin, allowing for micro control to turn the camera on, then control over USB.
     
  12. gvi70000

    Thread Starter Active Member

    Oct 4, 2009
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    I don't need to torn the camera on/off (only the sensors). Any way, using Canon SDK i did some testing using a small vb program and the camera is lagging too much on usb, it is way faster on remote control port.
    So, i'm guessing that image transfer and usb connection is out of discussion
    all that remains is the wireless mode and maybe a bigger screen.
     
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