Quiz-O-Tron 3000: Arduino quiz contestant lockout system

If you have ever watched a TV quiz show you have probably seen contestants trying to press a button in order to win a chance to answer a question. The contestant’s quick reaction time results in some kind of light and/or sound indicating victory. This is a practical way to choose the next focus of the game’s activity and it adds a bit of excitement to the process. So when the holiday party planning committee decided to have a trivia contest I decided to build a quiz contestant lockout system to add an extra dimension of fun to the festivities. This would help the planning committee’s mission of creating some entertaining activities for the event.

The minimum requirements were to have a system with multiple buttons that contestants press for a chance to answer a question. The first one to press the button would lock out the other contestants. The system would need to have a simple way to quickly identify who pushed their button first. And finally the system would need to be reset for the next round.

Considering the venue of the holiday party (an upscale wine bar) I felt that the contestant buttons would be one of the most important features. They needed to be hefty and able to withstand abuse by hoards of “beverage enhanced” partygoers. Fortunately I had encountered a really good contestant button candidate while visiting the local office supply store. Staples’ “Easy Button”, as made famous in their humorous ad campaign, is available in their stores. This device is a palm sized button modeled after the one seen in the Staples commercials. It is battery operated with a speaker that says “That was easy” when the button is pressed. It is well made and the ideal shape and size for use by a quiz contestant.

Given that the button is a self-contained electronic device I was confident that I could open it up and extend the switch functionality to the system I was building. The $5 cost was reasonable for the quality of the item. Plus Staples is donating the proceeds from the sale of their Easy Buttons (up to $1,000,000.00) to the Boys and Girls Clubs of America. So, planning to build a system that would allow four contestants to play at once, I grabbed four of these and left the store feeling good about my purchase for a number of reasons.

Now that I had the contestant user interface worked out I needed to decide how to implement the system functionality. Due to time constraints this needed to be done with material I already had. This turned out to be an Arduino Uno, one of Adafruit’s Proto Shield kits and some miscellaneous parts. Here is a picture of the completed system that I dubbed the “Quiz-O-Tron 3000” (QT3K for short).

Step 1 Tools and Materials

If you are new to microcontrollers or curious about controlling electronic devices with the Arduino, you may find this instructable helpful. In addition to some background info and explanations, I have included information in some of the steps that may provide you with techniques that can be used for other projects. I’ll discuss some alternate uses for the hardware built for this project later. But for now, here is a list of the tools and materials that were used to create the QT3K.

1 – Arduino ( http://www.arduino.cc )
1 – Adafruit Proto Shield for Arduino ( http://www.adafruit.com )
4 – Staples Easy Buttons
4 – Metal project boxes
1 – Plastic project box with aluminum panel
1 – 9V DC power source (battery, AC adapter, etc.)
20 – Red 5mm LEDs
21 – 3/16” rubber grommets
20 – Rubber feet
20 – 330 resistors
4 – 10k resistors
4 – 2.2k resistors
4 – PN2222A transistors
4 – 1.5k resistors
4 – 15k resistors
4 – 10uF electrolytic capacitors
4 – LM555 ICs
4 – 8 pin DIP sockets
4 – DB-9 female & chassis mount hardware
4 – DB-9 male & chassis mount hardware
4 – DB9 M-F cables with at least 4 straight through conductors
1 – panel mount momentary pushbutton switch
4 – perf boards
hookup wire
heat-shrink tubing
Velcro
solder
soldering iron
screw drivers
nut drivers
needle nose pliers
small hand files
Dremel tool
Dremel drill bits, cutting wheel and cutting bits
power hand drill
standard drill bit set
440 screws, nuts, washers

Comments

[nyckid]

Nice setup! I would suggest using Cat5/Cat6 cable instead of serial cables since you're only using 4 wires. There's still room for expansion, but if you set it up with RJ45 jacks and use standard patch cables you can extend the range very inexpensively. :-)

-Ryan

[RoysterBot]

Thanks Ryan!

[heato]

Awesome project RoysterBot! I am attempting to build one, but I think I have run into a stumbling block. I decided to try telephone cable as the interconnects, as it has 4 conductors and handy plugs at both ends. I think this is my problem though, I test the contestant boxes with a 9V battery & no cable and they work fine, but at the end of the cable I get no response. Do you think I am having this problem because of voltage drop on such a small wire? Could you post the size of wire that you used? Any help will be welcomed. Thanks again for sharing this fun project.

[RoysterBot]

The wire I used to connect the button boxes was about 20 or 22 gauge. Telephone wire should be able to handle the 9V. Have you tested the voltage you're getting at the button box end when you connect the battery to the wire and confirmed the proper polarity?

[heato]

Hello to everyone! My project was a success! The Telephone wire connects worked fine, and was a quick and easy solution with ready made cables. My problem was in my layout or schematic. Had I plugged in all of my button boxes, I would have discovered my issue much sooner! It seems that box 1 & 4 worked fine, but box 2&3 the flashing lights were crossed. When the contestant button on #2 was pressed, the lights would flash on #3! (and vice-versa) I laid this out as closely as shown in the pictures in this tutorial, but somewhere there was a mix-up. At that point there was two ways of solving the problem, one would be to remap the code in the sketch, two would be to switch the wiring on the shield. If you run into this problem yourself, pick the solution that you feel most comfortable with. Have fun and good luck stumping your contestants!

[RoysterBot]

Congratulations and thanks for posting!

[msamples795]

will do thank you very much for your quick response

[phunt46]

I see the board model you used is the CA68-03C for this illustration. Have you came across the same make but board model T11A39?

[RoysterBot]

No I have not. I did not know there was a new version of the Easy button. Does it have new/different functionality?

[phunt46]

Same functionality just different boards. Tried multimeter on board, with no luck on any contacts. And yes, the batteries are inserted :). Pic below, is attached.

[RoysterBot]

That looks like a much nicer board. Please send me a high resolution version of that photo in email to [e-mail] and I'll see if I can pick the best places to connect to in order to capture the switch functionality. I'll mark up the photo and send it back to you.

[msamples795]

hi RoysterBot i was having the same issue with the T11A39 i see one pad to attach for one side of the switch but i cant find where to attach the other my email is [e-mail] if you think you can forward that photo to me as well if that's okay

[RoysterBot]

I'll send you a suggestion via email. If you can confirm the modification works I will update this instructable with the results.

[Beergnome]

very nice! and pretty simple and straight forward for a beginner/ intermediate Arduino/electronics person. Looking at this project is giving me ideas. We have a trivia night here at the pub and this would be a great way to augment the competitions. And the way you described your trivia competition is pretty much right in line with how I was thinking about changing up the game.

and you are right about the PWM circuits. I was thinking that a RGB LED could be used to give an indication to who chimed in first, second, what have you could be illuminated with a corresponding color, and the first responder could get the rainbow effect

of course, I believe this wold entail replacing the 555 timer with a ATmini with the proper code, that could be triggered by the MCU.

once again, great work!
and the Arduino is pretty there is also the notion of of having a scoreboard, perhaps one on each slap unit. but I'm thinking we would be approaching a Arduino unit or just a custom PCB with a Atmega in each base unit

[RoysterBot]

Thank you for your kind words!

I would be interested to learn about your version. Keep me posted.

[lamandoh22]

Good morning,
Please can you give an approximate cost in dollars of this project. Also, you only listed where the arduino and the shield can be purchased, can I assume that everything else is available at radioshack. This is a really impressive instructable and I admire the fact that you've laid it out so elegantly. Thank you for your time.

[regulustech]

I bet you can get this cost down significantly. I used large pushbutton timers I got from Electronics Goldmine for $1 each and gutted the inside and replaced with my own pcb or perfboard. Since the pushbutton timers had a large plastic body I didn't need a project box for each button.

I mocked up the project using my arduino but then transferred the 328 to a perfboard arduino that cost about $7.

Bought 1 project box for the brains at radio shack for $3.

A handful of LEDs.
A spook of telephone wire for the hookups between the buttons and brains. ~$7.
Also you could go cheaper on the connectors (or go without) between the buttons and base station.

I think that was it. So you could get away with spending possibly under $30.

[RoysterBot]

This is great advice. Do you have details on the perfboard Arduino that you used? Thanks!

[regulustech]

For anyone else that wanted to find it too:
http://www.instructables.com/id/Perfboard-Hackduino-Arduino-compatible-circuit/

[RoysterBot]

I found your Instructable on the Arduino perfboard. Thanks again!

[RoysterBot]

Hello! Thank you for your kind works. The cost was about $180-$200 US. This is mainly becase I used some expensive metal cases to mount the Easy buttons on. The Arduino and Proto Shield can be purchased from Adafruit Industries. Their web site is located here...

www.adafruit.com

[Da Unknown]

I've been looking over this for a couple of weeks now. I've been meaning to ask: does the wattage of he resistors matter for this build?

I'm starting to get things prepared for this build, even attempting to use the suzo/happs buttons if possible like masterhibb. Thanks in advance

[RoysterBot]

The wattage of the resistors is not critical but I would not go below 1/8 watt. Let me know how your build comes out.

[masterhibb]

I noticed a few people in the comments looking for alternatives to the Staples "easy" button. I'm working on building a similar system myself, and I found some large arcade buttons here: http://na.suzohapp.com/pushbuttons/954002xxxxz.htm.

They're more expensive than the Staples buttons, but they've got a much nicer feel to them, and they are still built to stand up to abuse (since they're designed to be mashed on hundreds of thousands of times at an arcade). They also have the added benefits of coming in multiple colors, and having a built-in light so the whole dome can glow when the player buzzes in.

[RoysterBot]

Those are awesome buttons and would be a good solution for someone who is serious about hosting Quiz Bowls.

Thanks for the post!

[qvision1]

hello,

the project is great! and i want to build it. My dad made the suggestion that why use the 555 time module at all?

Can't the software make the transitor go on and off so that the led's also go on and off ?? Then you don't need the whole 55 time thing and you could adjust the blinking speed as wel! plus it'll be less expensive to build and less time consuming.

Any ideas? I'm going to try this out for myself, but b4 i do i'd like to know if this is at all possible?

[RoysterBot]

Hello,

You certainly could do as your dad suggests and have all the LEDs blink in a programmable pattern. I used the 555 circuit because I have a ton of them laying around and the circuit allowed me to easily implement LEDs that blink with an alternating on/off pattern. Plus I plan to add sound effects to that 555 circuit board so I just want the microcontroller to send an on/off signal.

Let me know how your version works out.

Thanks!

RoysterBot

[sbiltoft]

Is it possible to do this for 8 buttons. We need a cheaper quiz bowl system for our high school then the $300 ones they have available to buy. I'm really green with all of this so if this is possible...how?

[naic98]

look for "eggsbert" dedicated/stand alone system, reasonably priced

[RoysterBot]

The system in this Instructable could be made to handle six buttons using the Arduino Uno and extending the I/O pin interface techniques used. This restriction is due to the limited number of digital I/O pins on the Uno. Moving up to the Arduino Mega with its' additional digital I/O pins would allow for using the same techniques and extending the functionality to 8 buttons. The Uno could be used but we would have to incorporate some new I/O pin interface techniques for 8 buttons. There are less expensive ways to build a system like this without using the Arduino if you are budget constrained. You might find some kits on the Internet that you can use to build what you need.

[technologybuzz]

How would you go about doing that, because we would like to create a buzzer system with 12 buzzers and I am bit lost. How would I wire up the system and what code would I need to change (I'm assuming that it is just pudding with with more values to check)

[RoysterBot]

I will respond to you via the Instructables messaging system to see if I can help you with the details for what you are trying to accomplish.

[Chowmix12]

Remember, you can also use the 6 analog input pins as regular digital i/o pins. That may eliminate the need for a larger board.

[RoysterBot]

Does digitalRead() work on an analog pin? I have never tried that.

[Chowmix12]

It does.. you just have to declare it as A1 instead of just 1

[sbiltoft]

Thanks for the reply. I'll look into the less expensive budget route. You have a great project here, very well organized.

[lokeshjb]

Hey Royster mate !!!
Cool project .. Will start on it pretty soon. 1 question, (atleast for now) How do you mount Adafruit Proto Shield on the Arduino Uno ? Does it need soldering between 2 of them or it just clips on?
Thanks in advance

[RoysterBot]

Hello!

The Arduino board has female header pins that mate with male header pins on the shield. These headers plug into each other. So the shield is easily removable. This way you can use the Arduino for other projects when you're not playing trivia games.

Thanks for your feedback. I would really like to hear how your version of the project works out. Drop me a note on your progress if you have time.

[lokeshjb]

Fantastic .. just put a purchase order for it. Next purchase is Arduino Uno. Thanks mate. You are awesome

[lokeshjb]

Most of the parts have arrived. Will start soon. Any alternative to these EASY Buttons. Ordering from States is quite expensive. I am in Australia