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Electronics 7-segment LED Clock

Discussion in 'Modding' started by Explicit, 27 Sep 2004.

  1. eutronix

    eutronix New Member

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    My clock also has sound, but from an Oki ML22Q58. It can store a megabyte's worth of sound in it's own flash memory at up to CD quality.

    Stu
     
  2. Mike K8LH

    Mike K8LH New Member

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    Excellent job (what's your name?). That's got to be a labor of love (grin).

    I never tried building a Clock using discrete TTL logic though I did build a frequency counter using discrete 7490's, 7475's, and 7447's back in the mid' 70's. I built my first clock around that same time using one of the hybrid one-chip solutions that were becoming popular then.

    Anyway, just for contrast and giggles, here's a 1-chip concept using a PIC micro controller. I haven't built this one yet but I did build a 4-digit common cathode version prototype last year that works quite well.

    Have fun guys. Regards, Mike

    [​IMG]
     
    Last edited: 15 Mar 2007
  3. BobMJeffries

    BobMJeffries New Member

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    Hi,

    I'm interested in the BIG digital clock idea from a completely different hobby area.

    I'm heavily involved with an amateur off-road motorcycle club in South Wales, we organise enduro's which are off-road motorcycle competitions where the riders compete against the clock to complete a course in a set time. Along the way there are checkpoints and at those checkpoints we have digital clocks - but flap type.

    We currently use Grayson G222 & 224 clocks (http://www.graysonclocks.com/itemdetail.aspx?i=G222&c=20) which are great but can be fragile. We are looking to get some large digital electronic clocks, possible all synchronised either from a single source (keypad) before being sent out to the checkpoints.

    The checkpoints are in very remote locations so the clocks have to be battery operated. They need to be visible in bright sunshine from at least 40m, so should have 50mm to 100mm digits, preferably 100mm. They also need to be pretty robust and weatherproof, but we can sort that out ourselves.

    I have seen clocks that use very bright LED arrays or 7 bar electro-mechanical segments (like at petrol forecourts) but can find nowhere to buy them at a cost we might be able to afford (ideally < £250 each but possibly more for the right clocks).

    Does anyone know either where we can buy some or is anyone interested in a paying project?

    Thanks for taking the time to read this.

    Regards
    Bob Jeffries
     
  4. l0cke

    l0cke New Member

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    This thread is very :rock: !

    I wish I could do half of this clock stuff. Well, I probably could build one or two, but I'm too lazy and poor lol!
     
  5. Mike K8LH

    Mike K8LH New Member

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    Those Binary clocks look interesting but I don't have enough fingers to count binary (grin). How about a packed BCD design variant?

    [​IMG]
     
    Last edited: 25 Mar 2007
  6. geogecko

    geogecko New Member

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    :jawdrop: Cool thread, guys.

    I have been trying multiple searches within Google, and have turned up empty handed.

    Does anyone know if someone makes a 7 segment LED display that is RGB? I've seen the 8x8 dot matrix that is RGB, but for making several clocks for family members, those get a little expensive.

    Thanks!
     
  7. SteveyG

    SteveyG Electromodder

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    I've only seen tri-colour 7 segment displays, never RGB.
     
  8. geogecko

    geogecko New Member

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    What three colors have you seen? Red/Green/Amber?
     
  9. geogecko

    geogecko New Member

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    LOL, I guess I could just use RGB LED's in a configuration similar to what you did...

    I'm interested in how you did yours, but will read up more later. Seems like you could construct your own 7-segment display using individual LED's in groups...which is maybe what you did.
     
  10. SteveyG

    SteveyG Electromodder

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    Seen the tri-colour ones in the Red/Green variety.
     
  11. eutronix

    eutronix New Member

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    Depending on how much money you are willing to spend, you could have one custom made as I did. The cool thing about a custom job is you can have any custom symbol or segment shape you want. The down side of course is cost for tooling and high minimum orders.

    Stu
     
  12. geogecko

    geogecko New Member

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    Yeah, a little higher cost than I wanted to spend. It would be nice to keep the entire cost of each clock less than $100, and 1/3rd of that is eaten up by the CMMR-8D module. Packaging may also eat a big chunk, along with the boards...so I may have to increase that to $150 or $200...who knows...
     
  13. eutronix

    eutronix New Member

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    My clocks will hopefully cost less than $100 each too, but will have to be made in fairly large quantities to reach that goal.

    You are using the CMMR-8D too? Have you gotten yours to work? I've finally gotten mine working. There were some strange and undocumented grounding issues that were preventing it from receiving a signal, but now it works great.

    Stu
     
  14. geogecko

    geogecko New Member

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    I was planning on only making maybe 3-4 clocks.

    I haven't actually ordered the CMMR-8D module yet, but from what I can tell, it's the only one currently available...I am having a problem trying to find someone that carries the CMA-MF-60 antennas, but have sent them (C-MAX) a sample request to try and get some, $2 seems like a reasonable price for an antenna.

    What issues did you have with the module? Did you contact C-MAX about them, or just figure it out on your own?
     
  15. eutronix

    eutronix New Member

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    You can get the CMA-MF-60 antenna from Digikey by special order. It costs somewhere around $1.68. If you get the bugs worked out, it is far cheaper to use the CME8000 and your own layout than to use the modules. If you do use the module, you will not need an antenna as one is included. I would have to look back at various notes, but there were issues with pins DEM and PK. We had them grounded like the datasheet for the CME8000 shows, but in fact they should be left open. This we got from several e-mails from them. They seemed quite helpful.

    Stu
     
  16. geogecko

    geogecko New Member

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    LOL, I just did IM with Digikey, and asked them about special order, and they didn't seem interested in doing it. I asked what a minimum buy was, and they said that C-MAX would have to tell them that...they didn't even offer to quote it.

    I was wondering if the module included the antenna, but it was hard to tell from the web site. That is good, at least for development.

    So did you have problems using the module, or the CME8000 chip (sounds like the chip, to me). It does look at if they are using some extra parts on the module, that I wouldn't need, for instance, the crystal filters for all three bands, and maybe some others. I will need to look at the datasheet some, and see if I feel like going that route.

    How many antennas did you have to order, when you ordered from Digi-Key?
     
  17. eutronix

    eutronix New Member

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    I called them, told them I wanted 10, they contacted C-max and e-mailed me back a few days later with a PDF quote. It was for budgetary purposes only so I did not buy any. It may be that you have to represent a business to get a quote, I don't know. I never did get any samples from C-max even with the business.

    The problems were with the module, not the CME8000. Our PCB board accommodates both, but we decided to start with the module.

    Stu
     
  18. geogecko

    geogecko New Member

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    Any idea if surface mount RGB LEDs would look good in a configuration similar to your 3 dot, 7 segment 5mm LED displays?

    Have you ever tried just regular one color SMT LED's in a configuration similar? Just wondering if it looked good, or if you would have to use more dots per segment.
     
  19. SteveyG

    SteveyG Electromodder

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    Can't say I've tried SMT LED's since I've not tended to use them in the past and I've never actually purchased parts for any of my clocks - they've all been built with components I already have taking up 80% of the space in my room :lol: (That is apart from the massive matrix display which I did have to go out and buy the components for...).

    I can't see why it wouldn't look any good with SMT LEDs, but I'd probably increase the number of LEDs to 5 or 6 per segment using 0805 LEDs.

    I'm currently working on a much larger project, so don't have time to build any other clocks at the moment.
     
  20. geogecko

    geogecko New Member

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    Thanks, well, I might check into this myself, maybe with a test board.

    I hope that you plan on sharing (that is, if you can) your "much larger project?!"
     

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