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Topic: Quiz Bowl lockout buzzers? (Read 8223 times) previous topic - next topic

szac

Hi, basically looking to create a version of the QuizMachine commercial buzzer for my friend's high school. Two teams of at least 4 players and when someone hits their buzzer, they lockout everyone else until the system is reset.

Anyone got any pointers on where to start? I'd like to be able to daisy chain each player button/light.
 
Here's what the unit looks like for over $300!



brutus1975

Hard to tell exactly from the pictures, but it looks to me that each controller has 2 RCA connectors.

That'd give a person 4 lines to work with.. Blue RCA for +5/GND.. White RCA I2C/Serial?

You could interrupt -  sent back on center of White and Serial "I did it!" string on the shield wire.

If you sent across the 5V and ground on the shields of the two RCA connectors, inside each box you just would need an ATMega and a single resistor for the light (Assuming LED not incandescent).  You then have the two center conductors left over for communication.  Send an Interrupt back on one that stops all others from working, and notifies the host that it was pressed.  Then send ID serially over the other wire, pause and wait for reset command to return for all chips.

szac

#2
Jul 24, 2009, 08:52 pm Last Edit: Jul 24, 2009, 09:05 pm by szac Reason: 1
That sounds like a great plan. Would I use an ATMega8 for each box and have them running like stand-alone slimmed down arduinos?  

Does this schematic describe what you're saying?

Oracle

I built one of these around 15 years ago with plans from Popular Electronics.  It just used a simple 8-bit latch circuit and worked quite well.

More recently I built a wireless version using the remote controls from the game Remote Possibilities.  I used an arduino for the receiver, and the only extra components were the IR module, the buzzer, and an RGB led.

retrolefty

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Does this schematic describe what you're saying?


Is that switch button wiring drawn correctly? Looks like it shorts +5vdc to ground when activated  :o

Lefty

brutus1975

I think that button should have been connected to the green wire.

szac

Copy that. Thanks guys. What do you think the sketch for these buzzer interrupts might look like?

mikeperks

#7
Jul 26, 2009, 02:05 am Last Edit: Jul 26, 2009, 02:10 am by mikeperks Reason: 1
You haven't told us how each box is going to be wired into the main controller and how you plan to differentiate between each box for both the button and the LED. What does the big picture look like? Is there indeed a separate microcontroller for each box?

One of the reasons that the commercial system costs $300 is because someone did a complete design and implementation which takes time and effort.

Edit: I found the commercial website for these Quiz machines.

szac

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Is there indeed a separate microcontroller for each box?


Yep. I believe thats what he's suggesting. Looks like about $4 each.

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One of the reasons that the commercial system costs $300 is because someone did a complete design and implementation which takes time and effort.


You are absolutely correct. But one of the reasons why I'm posting here is to learn how to do it myself. This forum and the arduino itself seems to promote that. I'm simply looking for a nudge here or there. If I am able to pull this off I plan on making an instructable so that kids can make their own Quizbowl buzzers. Empowering, recycling, learning, discovery.. you know, the joys of DIY.

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Edit: I found the commercial website for these Quiz machines.


Yep. I'm hot linking that image above right from their site. Since I'm not trying to clone their product exactly, I figured my description above would suffice.

mikeperks

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What do you think the sketch for these buzzer interrupts might look like?
I'm sorry but this is not learning to do it yourself. This is asking someone else to do the thinking for you and spoonfeed the answer.

How about you think a little more about that is happening in each box, what it's schematic might look like, also the control box, try using I2C to learn how it works, come up with a protocol for how the boxes communicate and the adjudication algorithm used by the control box. We can help you through some of this and give you nudges but you have to do the main part of the work.

brutus1975

What I love about the commercial version is how DIY it looks anyways.

szac

@Mike Perk  
I wasn't looking for someone to write the damn thing for me. "Might look like" is requesting to be spoonfed?  Sheesh..

@everyone
Mike Perk says it's ok for the entire arduino community to help me through some of this and give me some nudges, but I have to do the main part of the work. Thanks everyone! Now I know that someone is not going to come to my house and build my Quizbowl buzzer for me.

@myself
What an idiot I was to ask for help regarding what a sketch might look like. I should have known that the Mike Perks of the arduino community will NOT spoonfeed me arduino sketches. (punches self in the mouth)

Seriously... I appreciate all of the help offered up and have some great paths to explore.  And no, I don't really think that Mike Perk speaks for the entire arduino community. Thanks again

Coding Badly

Two things...

1. I don't know how you would do it but, if you can, a nice feature would be "loose wire detection".  It would be horribly unfair if one of the boxes (the last in the link) had a loose connection and wasn't working.

2. If I were in your shoes, I'd use something besides RCA connectors and (what appears to be) coaxial cable.  CAT5 (with stranded conductors) or basic phone line seems like a better choice.

retrolefty

#13
Jul 26, 2009, 07:15 am Last Edit: Jul 26, 2009, 07:16 am by retrolefty Reason: 1
Well before one jumps to sketches one should have an overall concept. First why have an ATmega chip at each players station. It's just a switch and a LED. So unless you are going to have wireless communications between the remote stations and the master control I think you just need one master station design, with a pair of digital pins, plus a ground wire going to each remote. You could use simple audio 1/8" stereo plugs, jacks and cables. No need to send separate power to the remotes, not needed.

A remote switch is a digital input to the controller and the LEDs are outputs from the controller. Your sketch only needs to scan the inputs to see which is pressed first and then sound a buzzer and light a LED. This is just a few steps up from the blink sketch so get to it. Might want a 'game reset' switch at the controller to reset all the LEDs and start the scanning.

Lefty

Coding Badly

Would the distance from the switch / LED to the controller be a problem?

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