Quiz Game Buzzer Bluetooth Edition




About: Software Developper by day, maker and learner by night/weekends ;)

So I made this Quiz Buzzer a while ago...


After using it for a while I got some feedback and decide to improve on it.

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Step 1: The Circuit Prototype

Here's the new circuit prototype with all the new pieces.

Step 2: Connectors

First I changed the connectors for the button boxes so they wouldn't be locked to the box.

I also used smaller wires so it's not as bulky when stored.

Step 3: Sounds

I added an amplification circuit for the sound because it wasn't loud enough.


I also added a volume button so it can be adjusted according to the loudness of the environment.

I used the ??? chip which offered all the possibilities I wanted.

Step 4: Code Optimization

I optimized the code in the micro controller, especially how the inputs were read, using the register directly instead of checking each input one at a time.

You need to check for the correct bit in the registry as see in the code example below...

B00000001 for A0

B00000010 for A1

B00000100 for A2


And you can check for more than one input at the same time

B00110000 for A5 and A6

This made the code faster, but also reduced greatly the risk of always having the same team answering.

void setup()
{ DDRC = DDRC | B00000000; // set PORTC (analog 0 to 5) to inputs bitsPortC = 0;



void loop()
{ bitsPortC = PINC;


if (bitsPortC == B00000001)



Step 5: Mobile App

The biggest part of all those modifications was to add an HM-10 Bluetooth chip to the circuit.

Along with this, came an Android application to control the box from a mobile phone. The mobile application can basically see which team is active (the LEDs in front of the device), the score and it decides if the answer is right or wrong.

Step 6: Settings

With the mobile application came, the possibility to customize the experience a little bit with settings... muting the sounds, adding a difficult mode where a wrong answer removes a point, choosing if people can answer at all time or if the game master needs to tell the machine it is "Ready"... to avoid people mashing the buttons and not knowing the answer.

Step 7: Conclusion

It was a lot of fun to learn how to program all this so it works on Bluetooth... Bluetooth Low Energy to be precise.

Now I'm looking forward to apply this knowledge to other projects.

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    12 Discussions


    Question 5 months ago

    This is a really awesome project! I'm in the process of making it myself. But I do have a few questions I'm hoping you can answer.

    1. I noticed you have two LEDs on the side of your main box I'm assuming one of them is for the power but what is the top led for the blueish one.

    2. I'm not that knowledgable in coding for an Arduino, but I do know how to program in languages like C++, Python, etc... so if you could please explain what you're code optimizations were and how I can implement them that would be great. (If you use GitHub or some other way for me to see the code that would be even better!)

    3. I'm thinking of adding a button on the top of the main box that doesn't allow anyone to buzz in so that a question can be asked first. Do you have any suggestions on how this can be implemented?

    4. Lastly, did you make the mobile app yourself? If so what did you use?

    I would be really appreciative if you could answer my questions, or tell me something you think is useful to know.
    P.S I will be using an ATMEGA328p as my final product.


    Question 6 months ago

    Hello, I too was wondering if you sell your buzzers? I have absolutely no programming skills, but would love to have a set as it would definitely help make some of my community support and counseling group topics, etc. more interactive when using game style approaches to introduce new material.

    Very impressive!


    Question 1 year ago

    hi there.thanx for your project here.it is a good.however i wonder, where can i get the code to make the phone connected to the bluetooth in the diagram above, because the 1st version, you provided the code, but this time, i cannot see it anywhere.thanks again.

    Lisa Sane

    Question 1 year ago on Step 1

    Do you sell your buzzers? Looking for a elementary school teacher. TIA.

    1 answer
    ClapotiLisa Sane

    Answer 1 year ago

    I sent you a message, did you receive it ?


    1 year ago

    An excellent project, I am ordering the parts to make this for a family member who always hosts really good quiz nights. I am a total newby and wondered if you can share the arduino scripts in full with the bluetooth code and the adjustments you have made. Love the app also, how about adding the ability to name a team in it? Thank you for creating this, hoping you can help me?

    4 replies

    Reply 1 year ago

    Thanks for your comments.

    The Arduino script is quite complicated in different classes, so I'm not sure it would make sense to share it here, it would take a lot of space and might be hard to use, but maybe I can try.
    For the team name, I didn't show it, but tapping on the name of the team shows a pop-up to change the name.
    Tapping on the score also allows to adjust it.


    Reply 1 year ago

    Hi Sir, can you share the arduino code for this version?


    Reply 1 year ago

    Really appreciate the prompt response, would you mind and would it be possible to email your code? It will be really useful for me as a newby to understand how you have coded everything, I can also get things up and running quickly for my relatives whilst learning. I can send email address if you are happy to do this but not sure I should post here Again thanks for a great project - at least 20 family members and friends will benefit and get a lot of fun from what you have made so it really is a genuine thanks. Awesome on the team names also.

    Best Regards... Andrew.


    Reply 1 year ago

    Bonjour pourriez vous m'aider aussi avec les code la parti electronique me pose pas de souci a priori par contre la parti programme me derange un peut pouvais vous aussi m'envoyer les code que je doi rentrer pour que cela fonctionne aussi ? si vous voulais je vous laisse mon adress mail ?


    2 years ago

    You might want to add capacitors to reduce false positives from rf noise in the cables, in case some cable lies too close to some other electrical device. Maybe your cables are short enough that this isn't a worry.

    1 reply