Mini Breadboy prototype :)

I finally have my initial “Mini Breadboy” prototype built!

Here’s a quick video of it.

The goal of this was to design it as a fairly plug and play STEM project to run for students at my son’s school. There is no soldering required for the students - and not too much for me if I just run it in groups of 10. We officially started this onTuesday of last week, and it’ll nice to have this playable prototype on hand for the next session. I think they’ll love it. I do :slight_smile:

The biggest challenge was definitely the tight spaces. The mass of wires barely fit, but with a careful/efficient approach, the case can be closed up without any difficulty. I spent a lot of time trying to figure out how on earth I’d get the screen wired up and still manage to close the case, and I realized I could run those wires under the Arduino and then route them to the back and to a female pin header, which works a charm.

Big thanks to @Mr.Blinky for both the inspiration of the original Breadboy, as well as the mountain of work he’s done to make this an approachable DIY project. Big thanks also to @bateske for making this an open source project. And a general thanks to everyone in the community here. It’s a wonderfully helpful place.

I’ll be sharing all the assets for this build (CAD files, AliExpress parts list, Fritzing wiring diagrams, etc) once I’m fully satisfied that it’s in it’s final state.


Here are the internals (pic from an earlier prototype):

And the ‘starting point’ for the students in the STEM program:

And the Fritzing diagram I used to plan it out:


Looks great. Has a student built one yet? Will love to see there reaction to your work!

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Looks Great! and even has a volume dial! :+1:


I can’t deny, the volume dial is my favourite part.

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Awesome! Wish I had a teacher like this. Are the buttons 3D printed or harvested from actual Game Boy Colors? They look exactly like real GBC buttons.

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Thanks :slight_smile:

They’re replacement GB Color buttons I got off of Aliexpress. I thought about 3D printing them, but these are much nicer.

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We’re just one session in so far. In about 3 weeks, should have 10 completed units. I’ll grab some pics. Tomorrow will be the first time I show this prototype to them. I’ll probably pass it around so they can each play it a bit as they work.

I was struggling on this a bit, and I almost cut it out of the final design because I wasn’t sure I’d have it working to my liking in time to start the program. I actually really like having it. It goes down to almost fully muted, and I use it a lot more often than I thought I would.

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What resistance value is the volume dial and is the buzzer a piezo one (high resistance) or electromagnetic one (low resistance) ?

42Ω Passive Buzzer 12MM*8.5MM 12085
B502 5K ohm 5Pin 16*2mm Dial Taper Volume Wheel Potentiometer

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Even though the description says “Piezo Buzzers”, 42ohms is too low for a piezo buzzer. It’s probably a voice coil magnetic speaker, especially since the specifications say “coil resistance”.

I’d be careful running it at high volume. 5V into 42ohms is 119mA and the 32U4 pins are rated maximum 40mA.

You may also wish to consider adding a DC blocking capacitor in series with the buzzer, in case one of the speaker pins accidentally is left high while the other is low, which would waste power. (A piezo buzzer doesn’t have this problem because it’s high impedance, acting more or less like a capacitor itself.)

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Thanks for the tip @MLXXXp. Looking at this post, it would appear that I may be able to simply add a 100R resistor in the circuit and that should bring it within the 40mA maximum. (This is pretty new to me, but Grumpy Mike on that forum seems to approve :wink: )

For the capacitor, again, as someone not knowing much about this, what size would I want?

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A capacitor that is too small will act as a high pass filter and you would lose some volume as the frequency gets lower. You would have to experiment. Somewhere between 1 and 10µF might work. Make sure it’s non-polarised.

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I’m completely unsurprised by these statements.

It’s something I’ve always missed from the Arduboy, partly for nostalgia reasons* but also because I find the full volume a bit much, so I usually have the sound off completely. I’d probably use the sound more if I could lower it to a more suitable volume.

* I used to turn the volume down on my GBA to conserve power, and after a while I got used to just playing without sound from time to time to get some extra life out of the batteries.

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Wow that’s incredible, I think that’s about as good as a solder-free 3d printed Arduboy can get! Really nice work!

And you are using this in a class too? That’s so great!

Would love to hear how it goes or let me know if you need any support!


Ok, I am suscribing o this post.

Tell us everything about this experience!

Just finished printing the tops yesterday. I’d have preferred yellow, but the school had a spool of orange filament, and I’m trying to keep costs down.

Moving on to the black bottoms and screen covers now.

I’ll snap some photos of current progress of the student builds this evening.


Love the bright orange color. The black stands out nicely with it.

In case of emergency play Arduboy :smile:

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I was thinking it was more “Halloween Edition” :jack_o_lantern:

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