Idea for new device - where to start?

Discussion in 'The Projects Forum' started by JugglingReferee, Feb 28, 2010.

  1. JugglingReferee

    Thread Starter New Member

    Feb 28, 2010

    I have an idea for a simple device. It will be housed in a small black box with a belt clip on it.

    The basic premise is a countdown timer (measuring seconds). The device should have a power button (that only responds to a 4-second hold of the button), a start button, a stop button, and a reset button.

    A small display should show how many seconds are remaining until the timer hits zero. My understanding is that LCD displays require much less power than an LED display, so using LCD is preferred.

    The value that the countdown timer reverts to when the Reset button is pressed should be changable by the user. So, a switch is required:

    Timer Mode and Set Mode

    In Timer Mode, the Start and Stop button do exactly that. In Set Mode, the Start button adds 1 to the Reset value, and Stop subtracts 1 from the Reset value. With a 2-digit display, the user could go as high as a 99-second countdown.

    Is this a hard circuit to design?
  2. Wendy


    Mar 24, 2008
    With a PIC or some other µC, not very hard. Depending on your level of fabrication skills it could be small too.

    Some programming required.
  3. KMoffett

    AAC Fanatic!

    Dec 19, 2007
  4. JugglingReferee

    Thread Starter New Member

    Feb 28, 2010
    Yup - those are all close to what I need. Thanks for that link.

    I would also need my countdown timer to beep once 10 and 5 seconds before the timer reaches zeros.

    The prices on those links are fabulous though.