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K8LH Novelty Single Chip Clock

Discussion in 'Electronic Projects' started by Mike - K8LH, Aug 8, 2008.

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  1. sananh

    sananh New Member

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    Yes it does get hot... Total current comsumption is ~200mA. I think it should be ok. The clock is running little fast compared to my digital watch ~1 second on 24hrs.
    Anyway thanks for sharing your work. Sananh
     
  2. transistor495

    transistor495 Member Forum Supporter

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    Sananh,
    Good work. What kind of pcb etching method did you follow? Did you make it yourself. Can you explain it.
     
  3. sananh

    sananh New Member

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  4. dave

    Dave New Member

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  5. kumarmahesh

    kumarmahesh New Member

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    kindly sent detailed circuit diagram of the clock/ regards kumarmahesh
     
  6. SteveyD

    SteveyD New Member

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    Sananh,
    Good work. Nice job on your project. Can you provide specific links to the two projects you combined? I know one is at the beginning of this thread.

    Mike, K8LH;
    Not sure if you recall helping me last year on my led clock project from Sixca.com using the TPIC6B595N's But Its finally completed and ticking away. thanks again

    Time to try a new one and I'd like to give this project a run, Do you have a BOM(Bill of Materials) needed for your project?

    I'd like to build it as its presented, then make a second one or alter the first in a countdown format which incorporates an alarm.

    Cheers
    Steve
     
  7. Mike - K8LH

    Mike - K8LH Well-Known Member

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    Hi Steve,

    I prototyped this one chip Clock simply to verify the design. While it works well, the Charlieplexed display brightness is awful. You really should be able to figure out the small BOM from the schematic -- some 1N914 or 1N4148 diodes, three dual-digit non-multiplexed common anode 7 segment displays, seven NPN transistors (2N3904, 2N4401, etc.), four momentary contact push button switches, etc.

    Regards, Mike
     
  8. SteveyD

    SteveyD New Member

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    Thanks Mike,

    Any solution to the display brightness?
     
  9. Mike - K8LH

    Mike - K8LH Well-Known Member

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    Yes. Use something better than this one chip novelty design (grin).

    More later. Gotta run.
     
  10. Gayan Soyza

    Gayan Soyza Active Member

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    Hi Mike(K8LH) whats the frequency you driving the speaker on RA1?

    Are you using any built in Timer modules to that?
     
  11. Mike - K8LH

    Mike - K8LH Well-Known Member

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    Hi Gayan,

    When the "beep task" is running it toggles the "speaker" pin during each 1 msec interrupt. Toggling the speaker at this 1 KHz rate produces a 500 Hz tone.

    Code (text):
    /********************************************************************
     *  interrupt service routine, 1 msec Timer 2 interrupts            *
     ********************************************************************/
     
    Code (text):
     /*                                                                 *
      *  beep task produces a 500 Hz 'beep' with 1 msec interrupts      *
      *                                                                 */
      if(beepctr)                   // if beep task running
      { porta ^= 1 << spkr;         // toggle speaker pin
        beepctr--;                  // decrement msec counter
      }
     
     
  12. Gayan Soyza

    Gayan Soyza Active Member

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    Thanks

    Now only I saw it.1mS is a nice rounded value.To drive piezos it needs about 2-3khz to get a smooth sound.It can be easily make this frequency by your software nice work.
     
  13. RafaelCamacho

    RafaelCamacho New Member

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    Hi Mike...

    In your pictures, we can see some diodes, what is their values?

    Thanks.
     
  14. Mike - K8LH

    Mike - K8LH Well-Known Member

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    The diodes are 1N914 or 1N4148...
     
  15. RafaelCamacho

    RafaelCamacho New Member

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    Hi Mike...

    It´s very hard to find 16F88... I will try to use a 16F628 to see what happens.

    Best.

    Rafael

    edit:

    Congratulations for your project!!
     
    Last edited: Dec 23, 2009
  16. RafaelCamacho

    RafaelCamacho New Member

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    No sucess to convert it to run in 628A... :(
     
  17. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Assuming it's not using any non-existant hardware it should be easy, both use the identical 14 bit core.
     
  18. RafaelCamacho

    RafaelCamacho New Member

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    I am using BoostC 6.97 in MPLAB IDE 7.50.

    I´ve just create a new project using PIC16F628A.

    When I try to compile:

    Clock.c(20): warning: unknown or invalid pragma (ignored)
    Clock.c(21): warning: unknown or invalid pragma (ignored)
    Clock.c(167:2): error: unknown identifier 'ansel'
    Clock.c(167:2): error: invalid operand 'ansel'
    Clock.c(167:8): error: failed to generate expression

    So, to compile, I need to comment this:

    // ansel = 0; // a2d off, digital i/o

    In MPLAB with BoostC, there isn´t a dialog to set the fuses... So, I do this in the programmer, just set PWRTE to ON and other to OFF/DISBALE

    In breadboard, I am trying to see what happens using only one display (seconds) and it show only a number 9.

    Only these parts:

    1x PIC16F628A
    1x Xtal 16Mhz
    1x 2N3904
    2x 22pf
    1x DISPLAY COMMON ANODE

    Merry Christmas
     
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