Digital Clock Help?

Discussion in 'The Projects Forum' started by WestwardV, Nov 21, 2013.

  1. WestwardV

    Thread Starter New Member

    Nov 21, 2013
    Hi Forum people!

    So I'm fairly new to this so it may be odd.
    I'm currently a A level student, and for my project ive decided to work on building my own Digital clock. As im not to good on them ive decided to stay well clear of micro controllers and just stick with old fashioned 4 Bit binary counters and 7 seg displays. My plan was to make it a little less boring and make one that displays, Years, Months, Days, Hours and minutes but im a little stuck and im sure there's ways around it, its just im not very knowledgeable at it and don't know them.
    Here are my issues:

    Is it actually possible????
    Not sure what type of astable to use? If I was just using one astable and just bumping it up over minutes hours days etc, I would have to have a astable that goes high every minute then goes back to low really quickly to make it as accurete to a minute as possible? ( Am I just Overcomplicating things?)
    setting it up to realise gap years different amount of days in different months etc?
    Is there a easier way to do this that I havent thought of (other than micro controllers)

    Most of this is probably me being stupid but some advice from people who know what there properly doing would be really helpful


    Brent :)
    Last edited: Nov 21, 2013
  2. MrChips


    Oct 2, 2009
    Don't get fancy. Displaying Year, Month, Day is not easy.
    Stick to just Hour, Minute, Second.
  3. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    By refusing to use a microcontroller, you make the project massively complicated (tons of IC's and wiring) and that makes it very hard to construct and debug.

    I know that's not what you wanted to hear, but if you want all those features maybe you should re-consider?

    If you are set on making a clock without a microcontroller, that's fine, lots of people still like to do that. But anything more than a simple HH:MM:SS clock will get VERY complicated!

    Have a google around for "DIY clock using logic chips" etc. You can see how complex they are, especially if you want special features like day, date and month.
    WestwardV likes this.
  4. tracecom

    AAC Fanatic!

    Apr 16, 2010
  5. MrChips


    Oct 2, 2009
    Designed and built by masochists for masochists.
  6. Metalmann

    Active Member

    Dec 8, 2012
    Click above to view kit contents.
    This is an electronic kit for the experienced hobbyist.
    The result is a wall hanging clock that shows 1250+ parts in all their glory.
    There are no Integrated Circuits, all functionality is achieved using discrete transistor-diode logic.
    The included assembly manual has a logic tutorial and the circuit descriptions and attempts to explain how the clock works.
    The kit comes with all parts and the PC board with the part symbols showing the values of the components for easy assembly. Solder and solder-wick (we all make mistakes) are included, along with spare parts for most items. All you need is a soldering iron, some basic soldering skills, and a few tools.

    I don't think I'd have the time or patience, to assemble over 1200 pieces.;)
  7. elec_mech

    Senior Member

    Nov 12, 2008
    Welcome to AAC.

    As others have stated, accurately displaying years, months, and days will get complicated fast. Incrementing the display is easy, but you'll probably end up with a PCB the size of a poster board or bigger when you're done to account for different days in each month, leap years, daylight savings, etc. This will cost you an immense amount of time and money to do.

    If you want to pursue displaying years, months, and days and you are allowed to use a microcontroller, look at a PICAXE, a DS1307, and a MAX7219. The PICAXE uses the BASIC language and is extremely easy to program. The DS1307 handles the timing aspect including accounting for years, months, days, hours, and minutes. It will even tell you the day of the week if memory serves, so you could add an LED array to signify the day of the week (one LED for each day of the week). The MAX7219 allows you to control up to eight digits, so you'll need two. Alternately, you could easily use an LCD which would cost less and allow you to display text (such as the day of the week).
    WestwardV likes this.
  8. WestwardV

    Thread Starter New Member

    Nov 21, 2013
    Thank you all so much for the help its great to hear from people who know what there doing!

    I think im just going to have to go for it and use a micro controller, having a good look around myself I think your right and Ill have to reconsider.

    Was using CMOS 4510B's which simplified it considerably but If i want to do years and months etc Micro controller is the only way it seems

    Thanks guys your all a great help!
  9. Austin Clark

    Active Member

    Dec 28, 2011
    If you're clever, I'm sure it can be done much more simply than is let on. It will still take some doing, but certainly not a "poster-sized" nightmare. ROM-Based decoding could simplify the design substantially I imagine.

    Leap years would be the most difficult thing to implement I think.
    Daylight savings would be another, if you decide to make that automatic.
  10. MrChips


    Oct 2, 2009
    I started a project to build a 10000-year clock that needs no adjusting.
    I had ordered some LCD displays through the internet and they never arrived.
    I haven't found the time to look for another source. One day I will get on to it.
    WestwardV likes this.
  11. WestwardV

    Thread Starter New Member

    Nov 21, 2013
    That 1000 year clocks look really interesting I read through most of your blog seems like a great project to build!

    I was reading through and researching some more things and I think the only way I could do it with just CMOS chips is just HH:MM:SS as its so much simpler. If I wanted to increase that with YY.MM.DD I think ill use a microcontroller.

    I was recently reading through this which... well I thought it was awesome. Check it out it looks like a great project to do, I may consider it myself if I have the time.
    elec_mech likes this.