Help creating a DIY Scoreboard

Discussion in 'The Projects Forum' started by norbie, Jan 16, 2015.

  1. norbie

    Thread Starter New Member

    Jan 16, 2015
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    Hi all

    I'm a newbie here and although I have a lot of experience in IT/Computer Programming when it comes to micro electronics I'm quite a beginner!

    I've seen a project online that I would really like to replicate for my sports team. The problem being that the parts are no longer available, at least not in the UK anyway where I am based.

    It's a wireless electronic scoreboard which features 2 x 2 digit up/down/reset counters with large LED displays, and a remote control:

    http://perfectmancave.com/forum/showthread.php?p=397621#post397621

    Photo of wiring:

    [​IMG]

    Schematic:

    [​IMG]

    The schematic is something I can understand as it uses pre-assembled parts. I have found exactly the same remote control which is handy, but I can't find anything pre-assembled for the 2 digit up/down/reset counters here in the UK.

    It can't be that hard to build one can it... ?

    There is a kit in the US available but that's no good to me here in the UK - http://vakits.com/large-led-updown-counter-display-kit-4192

    The components on this seem simple enough and I'm sure I can get hold of them, but I have no idea exactly what parts, and how I might program it (numbers - up / down / reset) when they're all put together?

    [​IMG]

    Is anybody able to assist me in sourcing the right parts to assemble and program one of these?

    Many thanks in advance.
     
  2. MrChips

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    Oct 2, 2009
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  3. norbie

    Thread Starter New Member

    Jan 16, 2015
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    Thank you I'll take a look. Do you know if there is a variant in there that counts up & down from pulses though? That looks to be an automatic countdown from what I can see.

    This looks very relevant http://forum.allaboutcircuits.com/threads/creating-an-electronic-scoreboard.92859/

    I'd need a more detailed shopping list & schematic if I've ever a chance of creating one myself though :(
     
  4. MrChips

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    Oct 2, 2009
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    Counting up or down from pulses is standard fare in digital electronics.
    Before you go sourcing parts and shopping you want to lay down your specifications.

    What do you want to display to do?
    How many digits?
    How large and visible do the displays have to be?
    What are the control buttons and inputs required?

    This is called Top-Down Design.
     
  5. norbie

    Thread Starter New Member

    Jan 16, 2015
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    I would like to have 2 x 2 digit displays to mount on a board. "Home" and "Away" scores.
    I would say the digits need to be around 10-15cm high and work well in daylight as well as in the dark.
    An RF remote can trigger either the "home" set or "away" set to go up, down, or reset to zero. The most a set of digits would need to go to is 13 so 2 digits is sufficient.

    The diagram above shows how it would fit together (roughly). Pulses from the RF controller would trigger the up/down/reset, mapped to different buttons on the remote.
    That is the only functionality required.
     
  6. MrChips

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    Oct 2, 2009
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    Good start.
    How will the display be powered?
    What is the maximum distance between the display and the remote controller?

    I may suggest using an IR controller instead of RF.
    Also you do not need separate signals for up, down, reset, etc.
    The remote controller will send out a digital encoded command which will then be interpreted by the receiver MCU to generate the desired display. You do not need counters. One simple MCU directly interfaced to the LEDs will work. Multiplexing four 7-segment displays is relatively straight forward.
    You need to start figuring out how to build or buy displays 15cm high.
     
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  7. norbie

    Thread Starter New Member

    Jan 16, 2015
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    If it's easy enough to have a battery & mains powered option (12v I guess) that would be ideal. It may not always be fixed in the same place so having the ability to use batteries would be great.

    Maximum distance would be say 15 metres and line of sight shouldn't be an issue as it will be outdoors.

    I think I would have to build the display with either large LEDs or LED strips. Probably a load of large LEDs as strips would probably only make sense if I was going much larger.

    Interesting what you say there about no need for counters!
     
  8. MrChips

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  9. elec_mech

    Senior Member

    Nov 12, 2008
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    Welcome to AAC.

    How much work do you want to put into this? Build everything from scratch, hack existing products, etc.?

    At the base you'll need a controller. This could be done with a microcontroller (uC) or you can avoid programming altogether and go with a purely hardware solution such a CD40110 (one per digit). Both have their merits. While multiplexing everything using a uC is doable, I wouldn't consider it a trivial task. You could use a uC in combination with a multiplexing IC such as the MAX7219/21. Not a cheap IC, but it takes care of timing and brightness for you. MMcLaren has a project posted that uses a PIC to multiplex four digits. If you're feeling ambitious, check out here and here.

    Next, since you're planning on large digits, you'll need some type of amplifier to interface between the controller and the segments. A ULN2003 for a 5V uC will work or a ULN2004 for the hardware only solution.

    For the wireless portion, I've had good luck with something like this. Since you're only going up to 13, I wouldn't worry about a reset button. However, this could work too. This is best suited for a purely hardware solution, but it would still work well with uC if you have four pins to spare. MrChips suggests a single transmitter where you control the signal and can therefore write and read different data on the same line, so to speak. An elegant solution for a uC to save I/O pins, but it also requires more work and, if I'm not mistaken, another uC for the transmitter. Not a bad thing, just depends how much time and effort you want to put into it. As you can tell, I'm inherently lazy.

    For the segments themselves, I think LED strips would be good. You can make them to whatever size you need and I even saw some that operate at 12VDC. You can find pre-built displays, but most of these will be diffused and not bright enough for outdoor viewing, especially in sunlight.

    I've made some PCB's that use the hardware solution I mentioned if you're interested, however, shipping to U.K. from the U.S. might not be worthwhile. If nothing else, you can look at the picture below and "see" what a hardware only solution would look like. This is for two digits and accepts pulses to count up or down. There is a switch debouncer so it would work well even with relay-driven remotes. It operates off of 12V or so, but you could use up to 50V for the segments as long you keep power to the circuit around 12V and tied the grounds together.
     
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  10. norbie

    Thread Starter New Member

    Jan 16, 2015
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    Thanks so much for your help!

    I don't really want to do any programming if possible so the hardware solution sounds best to me. The reset button is definitely nice to have for laziness.

    Your PCB looks perfect! Would you be interested in shipping them to the UK?

    The digits do not need to be as large as the ones in the football example, it's for a petanque game (bowls) which is done at short range to replace the very old fashioned:

    [​IMG]

    For LED strips, do you think these would be sufficient? They are 12v DC, 14.4W, 1020 Lumens
    http://www.wholesaleledlights.co.uk...-m-5050-5-x-5mm-14-4-watts-m-1020-lumens.html
     
  11. elec_mech

    Senior Member

    Nov 12, 2008
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    Those look good. I assume they are easy enough for you to wire? I don't know if you can buy cables with connectors for them or if you'll need to solder wires to them.

    Regarding the PCB, once you have ten posts, I'll send you a private message to get your shipping address and work out cost. Do you want the PCB fully assembled and tested or just the bare board (requiring you to get the parts and solder them yourself)? I'm not trying to make a profit (from AAC members anyway ;)), but I do want the shipping and parts costs covered.

    You'll want to put the LED's in some type of enclosure to protect from the elements, unless you'll ensure they're never out in the rain in which case you can simply mount them to a board and put inside when not in use.
     
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  12. norbie

    Thread Starter New Member

    Jan 16, 2015
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    Apologies for the late reply, I missed the notification email!

    Fully assembled and tested would be perfect. Of course you need to recouperate your costs! If I can make a good product there may well be demand for more so perhaps I could learn from the preassembled ones and try to make one of my own next time :)

    Understood about the enclosure. Not sure about the wiring, the description seems to suggest they are "plug and play" with 12v power supplies, I'll speak to the supplier.
     
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