Photocell to change a usb flashdrive power

Discussion in 'The Projects Forum' started by sortish, Jun 26, 2010.

  1. sortish

    Thread Starter New Member

    Jun 26, 2010
    I have a basic start on this project and im having a hard time finding much in resources if my project is even possible.

    Get a usb memory stick/flash drive to be unread by a laptop (or the power turned off) unless an attached photocell receives a certain amount/strength of light then the usb drive is readable (withouth the constant light, a one time trigger for light sensed on/ light sensed again off)

    Over All Goal:
    have a computer login with Rohos Logon key when the usb device is flashed with light (from a "sonic screw driver")

    is it even possible to connect the photocell to the usb in sucgh a way and what wiring or programming would be involved, the wiring itself isn't to hard but its knowing what to attach it to on the usb flashdrive's motherboard.

    any help would be appreciated

    -very much a noob at this
  2. retched

    AAC Fanatic!

    Dec 5, 2009
    Sure, its possible. Look into laser communications. You could replicate a small version of that.

    The photodiode would read incoming light, the uC would wait for a particular pattern that the "Dr.Who" screwdriver would repeat when a proper button is pressed, shining the modulated light onto the cell.

    That would in-turn unlock the usb device. You could activate it via an SCR that way It would stay connected and unlocked until the power was removed by unplugging or turning off via USB control panel.
  3. sortish

    Thread Starter New Member

    Jun 26, 2010
    i was going to try the pny micro swivel but i don't see a way of wiring it i think i may need a new one

    I'm looking into the laser communications but not finding much on the actual programming of the photocell (as to how strong the light has to be to trigger power) is the one part I'm lost on and then where to actually connect the parts on the usb, on the ones Ive looked at at least its not clearly labeled for power.