IR arcade scoreboard

Discussion in 'The Projects Forum' started by Binchotype, Jan 20, 2013.

  1. Binchotype

    Thread Starter New Member

    Jan 20, 2013
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    Hi all, I'm working on a project for college and I have chosen it to be a type of arcade IR shooter game. What i plan for it to do is on the input side send an IR signal to an IR receiver, which i plan to make 2 or 3, then have that receiver once triggered sound a buzzer and maybe light a light bulb or something. There is something else i wanted this project to have and that is to keep score. In my mind i wanted 3 targets and different ranges each worth a different amount, such as one is worth 2 points, then 3 then 5, but I'm not sure of how to implement this or even how to start building a circuit for something like this. I was hoping someone might be able to send me good direction of what I should be doing. Thanks in advance.
     
  2. elec_mech

    Senior Member

    Nov 12, 2008
    1,513
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    Welcome to AAC.

    Sounds interesting and not too difficult to implement. What is the project for, i.e., class assignment, senior design project, etc.?

    Are you looking for a purely digital logic solution (several parts) or something requiring as few parts as possible (would require programming)?

    What is your background in electronics/programming?

    Are you planning to use a remote control for the transmitter or something else?

    Will the user be pointing the transmitter at the targets like a laser tag game or is the IR being used for something else?

    I assume you'll only be using one transmitter and won't need to distinguish between multiple transmitters? In other words, there will only be a single score?

    How high do you want to keep score, i.e., one digit (0-9), two digit (00-99), etc.?

    How big do you want the digits of the scoreboard, e.g., ~0.5" tall, 1" tall, 5" tall, etc.?

    If you opt for digital logic, you build small circuits that each perform a specific task and have them interconnect to work with each other. So one circuit would be an IR detector that would send out a single pulse when triggered. Next could be something like two 555 timers, one in a monostable setup to turn on a light for x seconds, another setup as an astable to send x pulses (3 for three points, etc.). The astable output would then go to something like a BCD counter which would then go to a BCD-to-7-segment display driver. A CD4510 and CD4511, respectively, for example or an all-in-one such as the CD40110.

    We can help you with a circuit, but we'll need the questions above answered.
     
  3. Binchotype

    Thread Starter New Member

    Jan 20, 2013
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    Alrighty, well this is for my capstone which is in short the final electronics class at ITT in which we need to create a project showing what we know and it's in the associates degree.

    I was going to try and use digital logic as I don't really have a whole lot of skill with micro controllers.

    Like i said i have about 2 years in school electronics. I know pretty much the basics of circuit design and i know odds and ends in digital and components. I will say digital logic is probably my weakest area though.

    The transmitter is an IR led mounted inside a toy gun behind a magnifying glass. I've done my research and learned that is how most people have gone about narrowing the IR beam.

    Yes the idea was kind of like laser tag so the transmitter will be directly pointed at the targets.

    I think going 0-99 would be a better range because i was going to have a countdown timer, and the goal would be to accumulate as many points as possible before the timer reached 0.

    Well to be honest i had never thought about this question. I'm not sure what size i want the digit size to be. To be honest i don't think it matters, and i haven't purchased the display i want yet.

    Well after reading that suggestion I do like the idea of the astable 55 timer to the BCD counter. As of now i have a the receiver going into a Darligton pair which activates a relay that helps to turn on the light, I haven't gotten to the buzzer part, but I'm going to look into your suggestion.
     
  4. elec_mech

    Senior Member

    Nov 12, 2008
    1,513
    193
    Since this is for a capstone project, allow me to suggest we provide you with some ideas and links to more information on specific circuits that should help you out and you can begin putting together a schematic. We can help constructively critique your design until you feel it meets all your objectives. At that point, you can get parts and begin prototyping and we can help you troubleshoot problems you may encounter.

    With that, it sounds like you have the receiver portion working. Could you post a schematic (could be as simple as a picture of a drawing on paper) of how you have it hooked up so far?

    Are you using an LED for the light indicator or something else?

    What voltage(s) are you working with to power your receiver and light?

    If you're in the U.S., RadioShack has some nice simple buzzers depending on the voltage you have from your power supply. One example: http://www.radioshack.com/product/index.jsp?productId=2102817.

    If the light (and ultimately buzzer) is staying on for the time you want, you don't need a monostable 555. If you want to control how long either or both stay on once the receiver is tripped, then read more here:
    http://www.kpsec.freeuk.com/555timer.htm#monostable.

    Before going into using an astable 555 to send 3, 5, etc. pulses to advance the score, I suggest working out the scoreboard circuit first.

    If you do not need the scoreboard to default to some value other than 00, a CD40110 would work well. It counts pulses and displays the value to a 7-segment LED display. It does not output much current, so if you're digit height is going to be much more than an half an inch high (or ~1.2cm), then you'll need to add a transistor of some sort between the output of the 40110 and the display, one for each segment.

    Alternately, you could use a CD4510 with a CD4511 (or a CD4543 - look at how the digits will look in the datasheets and see which one you like better). These are CMOS ICs and will work with 3-15VDC. You could also opt to use TTL which require 5VDC such as the 7490 with either a 7447 or 7448 depending on your use of a common cathode or common anode display. Make a note of this once you decide on your ICs so you get the right display.

    You can cascade two or more CD40110s, so getting 00-99 will be fairly straightforward, just refer to the datasheet.

    For now, I would suggest designing your circuit such that the receiver output triggers the display driver - one pulse equals one count on the scoreboard display. Once this is done, you can add a 555 in astable mode to get the 2, 3, and 5-point counts. This will work by having the 555 receive a single pulse and output 2, 3, or 5 quick pulses to the display driver. The scoreboard will appear to advance 2, 3, and 5 points, respectively.

    If you have a schematic for the countdown timer, go ahead and post it. Might be able to use a similar circuit to base your scoreboard on. You could ultimately incorporate it into the rest of the circuit to enable when the timer is on and disable when the timer is done.
     
  5. Binchotype

    Thread Starter New Member

    Jan 20, 2013
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    Alright again i just wanted to thank you for helping figure this stuff out, I'm already seeing that this will work out fine, and I'm open to any recommendations or critiques anyone might have.

    Now i have my attached my receiver portion of the circuit.

    As you can see I'm pretty much just working with 5v as of now. I had planned to make this all battery operated with 9v batteries so later I'm going to have to introduce some regulators but that won't be much of a problem.

    I do just have a plain led for the light right now, but the ones i have are pretty big and bright so i think they will manage for what i need them for.

    As for the monostable 555's i like that idea and i plan to implement that the next time I'm at school because the light and buzzers are definitely not gonna be on for long enough when triggered I hadn't even thought of that.

    Unfortunately I don't own any of these IC's as they didn't come in our school kit, so I went ahead and ordered a couple of the CD40110's and a LED display that is approximately ~.56" tall.

    I'll look into how the part works and try and get a schematic together so I'm ready to build when they come in.
     
  6. elec_mech

    Senior Member

    Nov 12, 2008
    1,513
    193
    I don't think the attachment made it.

    9V batteries won't last long, especially if you're planning to power everything with 5V. A brand name 9V has roughly 550mAh. A small two digit scoreboard will have 14 LEDs (2 x 7 LED segments). If you stick with low power, each LED will consume say 10mA. Worst case scenario is all LEDs are on (88) which means 10mA x 14 = 140mA. Not factoring in your timer, power to the circuit, buzzer, or loss from a regulator, you'll get 550/140 = ~4 hours of run time.

    Obviously, 88 won't be displayed the entire time, but this gives you an idea.

    If possible, I suggest using a wall wart to power your circuit and if you want to save a little space and time and stick with 5V (TTL), you can purchase a 5V regulated supply.

    You could also switch to AA batteries which have a much higher current capacity. A brand name AA battery has roughly 2500mAh. Of course, you'll need to use a few in series to get the voltage high enough. You might get away with 4 x AA for 6V and still use a 5V regulator IF your regulator is a LDO (low dropout voltage). In other words, able to produce 5V with only a 6V input (most will require the input be 1.5V or more than the output).

    If you go with CMOS, you wouldn't need to worry about a regulator. Once I view your circuit, I can see if it can be made with CMOS components if you'd like. If you opt to stay with TTL, that's fine too.

    If you have the components handy, you can go ahead and build the monostable and test it with an LED and a switch.

    Post your schematic when you're ready and we can critique it if you'd like.
     
  7. Binchotype

    Thread Starter New Member

    Jan 20, 2013
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    Well that was my fault, OK second time here is what i have in the schematic.
     
  8. elec_mech

    Senior Member

    Nov 12, 2008
    1,513
    193
    Hmm, I think you can eliminate the relay and one of the transistors altogether. If you use a PNP transistor, you can have the LED come on when an IR pulse is detected.

    Relays are great if you need to control something with a lot more power than a transistor can control or need to isolate the load from from the circuit, but for this application you don't need it. If you decide to keep it or use it in the future, but sure to add a protection diode across the coils.

    More on that and transistors here: http://www.kpsec.freeuk.com/trancirc.htm

    Also be sure to add a base resistor in series with the transistor base and the IR receiver output.
     
  9. Binchotype

    Thread Starter New Member

    Jan 20, 2013
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    Well I like relays since you can work them in reverse logic if needed, and having one means I can run more loads with it so I think I'm goign to stay with a relay for now. I'll try a PNP and see how it operates.
     
  10. elec_mech

    Senior Member

    Nov 12, 2008
    1,513
    193
    You can stick with the relay if you'd like, just note:
    • Add a protection diode across the coils - see the link I sent last time for more info.
    • Energerizing a relay coil is going to reduce your battery life if you plan to power this with batteries exclusively. You can determine by how much if you know or measure the current going across the coils when energized. You can reduce this somewhat by using a PNP transistor (perhaps array as you've shown in your schematic if needed) and only energizing the coil when a signal is detected.
    • Unless using a solid state version, a relay acts as a mechanical switch. This will add noise and may require a debounce circuit. Since you plan to use the 555's, they may act enough as debouncers to negate this (if you plan to use the relay to provide the signal, not such a worry if coming off the IR receiver directly or through a transistor).
     
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