Designing a Kitchen Timer using IC's and logic gates .

Discussion in 'The Projects Forum' started by rellik650, Mar 30, 2016.

  1. rellik650

    Thread Starter New Member

    Mar 29, 2016
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    Hello , I want to create a Kitchen Timer that has 3 input buttons : 'Start/Stop' , 'Set Minutes' , 'Set Seconds' .1)When you set minutes and seconds and press Start/Stop , the timer starts counting down until reach 00:00 on a BCD 7-segment Decoder ,activating an alarm(or just an simple led) .2)If the output is 00:00 and you press Start/Stop button it count up to 99:59 and then 00:00(and it stops).
    Do I need 2 sets(1 set = 4 counters , 2 for minutes , 2 for seconds) of counters to produce the both cases?How to design propely?
     
  2. rellik650

    Thread Starter New Member

    Mar 29, 2016
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    Sorry for triple posting . Can admin delete 2 of them ?
     
  3. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Cheaper to buy one than build one.
    Are you building this to gain experience, or simply because you need a timer?
     
  4. rellik650

    Thread Starter New Member

    Mar 29, 2016
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    Gain experience .
     
  5. WBahn

    Moderator

    Mar 31, 2012
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    MOD NOTE: The other two threads (neither of which had any replies) have been deleted.
     
  6. rellik650

    Thread Starter New Member

    Mar 29, 2016
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    anybody?
     
  7. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
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    Get on ebay plenty of choice and cheaper than making one.
     
  8. dannyf

    Well-Known Member

    Sep 13, 2015
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    Most of them are done via specialty asic or mcu.
     
  9. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    Here is a video that describes a countdown timer similar to what you are wanting. The project was designed by another member here and built by me; it does a little more than what you want, but not much. As you can see, the project is a bit complicated, but it may help you understand why some of the responses recommend buying rather than building.

     
    absf likes this.
  10. rellik650

    Thread Starter New Member

    Mar 29, 2016
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    I know that the idea of buying is better than building . I want to implement it to a FPGA so I need a basic scheme to see the internal process .
     
  11. TheButtonThief

    Active Member

    Feb 26, 2011
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    Is this a homework/coursework assignment? The criteria you gave us sounds very specific.
     
  12. AnalogKid

    AAC Fanatic!

    Aug 1, 2013
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    In the FPGA library there should be a presettable decimal up/down counter with both carry and borrow signals, similar to a 74LS168. One set of four of these form the counting core of the circuit. Then add steering logic around them to handle the operational conditions.

    ak
     
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  13. rellik650

    Thread Starter New Member

    Mar 29, 2016
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    Yes !
     
  14. ian field

    AAC Fanatic!

    Oct 27, 2012
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    Kitchen timers have always been a popular page filler in various electronics hobby magazines.

    There are probably PIC or AVR based variants in more recent issues.

    Probably a few projects floating about the web too.
     
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