Optocoupler Connection to PIC & Camera

Discussion in 'Embedded Systems and Microcontrollers' started by JDR04, Apr 12, 2015.

  1. JDR04

    Thread Starter Active Member

    May 5, 2011
    I'm planning to connect my digital camera to a PIC via a SFH618 optocoupler. The camera will be connected using a remote cable that is usually used to avoid shaking the camera.

    I've attached a datasheet and a schematic as tom how I propose doing this so my camera and PIC are protected. I would appreciate somebody checking it out and telling me if I'm doing the connection correctly or if there is a better way.

    Thanks a lot.............John
  2. tracecom

    AAC Fanatic!

    Apr 16, 2010
    It depends upon what your camera uses for a remote shutter release. Do you know that?
  3. JDR04

    Thread Starter Active Member

    May 5, 2011
    Thanks, I am aware that shutter release cables vary from camera to camera. However, most of them actually operate with the same principle, a half press closes two contacts which allow the camera to focus, a full press then closes all contacts which then activates the cameras shutter. I'm planning on using the camera in MANUAL FOCUS MODE which makes it a lot less complicated. Hopefully.

    I'm not really concerned with that part of it at the moment, its just if the optocoupler is connected correctly in the circuit.

    Thanks anyway for that.......John
  4. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    By guess and by gosh it looks like you have kinda sorta 17.5 mA min to drive the LED so it possibly may work if the guesses and assumptions I made about your circuit all proove true.
  5. RichardO

    Well-Known Member

    May 4, 2013
    I prefer opto-isolators that use an FET output for switch replacements. The advantage is that you don't have to worry about the polarity of the wiring. Just connect the opto output across the shutter button switch in the camera.

    Note that PIC's tend to have better sink currents than source currents. You should probably tie the LED anode to power and drive the cathode to ground through the resistor.

    edit: Added example of FET opto-isolator.
  6. JDR04

    Thread Starter Active Member

    May 5, 2011
    Thanks RichardO, this could prove to be very useful indeed. Does anybody know where this part can be sourced in the UK??
  7. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
    Never knew of this type of optoisolator. Thanks for the reference.