It's a glorified tally counter, if I'm being honest

[Torabi]

I'm not technically a beginner, but it's been... a decade or more since I've messed around with electronic circuits, and I've forgotten enough that I might as well be a beginner. I feel like I should probably know the basics about electricity and circuitry, but it's going to take some dredging to find it in my memory. Anyway, I was joking around with a friend, which led me to looking for a device that we thought surely must exist... but doesn't really appear to. So we decided we might as well try to make it, and learn something in the process.

So what we want to make is a box with a big ole button, kind of like those Easy buttons from Staples... Except it will say "Self Destruct" on it, and play a nice "Kaboom" or something when you push it. Now, there are dozens of buttons that will record and play back a sound on Amazon for $10+ a pop, but to give the project some kind of legitimacy, rather than just being for our own amusement, we'd like to put a counter on it, so we can check how many times people push the button. So we'd slap them on some things, and see what people would like to self-destruct the most. It's a social experiment! Ok, it's mostly for our own amusement. And education!

So I figure my basic list of parts is:

• button
• sound generator
• speaker
• counter chip
• numerical display
• battery

I expected the sound generator to be the most difficult part, but there appears to be a ton of premade solutions, probably because there are so many applications that call for recording and producing sounds, be it greeting cards or stuffed toys. And they're cheap! Probably cheaper and more powerful than rolling my own. Super overkill, but it seems like it would be silly to ignore them, even if it feels like cheating. Nuvoton has their ChipCorders for a couple bucks, and Alibaba has hundreds of options that might work, some for pennies per unit. So, the hardest part of this part may be picking a part.

Where I'm really strugging is to find a counter and display. Despite thinking that using a single-chip solution for recording and playing a sound feels like cheating, I somehow expect to find a single part to keep count and manage the display for me, despite the wide availability of instructions for wiring up a seven-segment display and programming a chip to do the counting. This seems like a common enough task that there would just be a display with four pins, two for power, one to increment the count, and another to reset the counter. And I've even found a product that I think does exactly that on Alibaba! So I should be set, right?

So I guess this is mostly a vibe check. I'm out of my element, trying to learn to swim, and looking to the pros for a little guidance. Am I aiming too high? Too low? Are these good places to be looking for parts? Back in the day, I'd have hit up a local electronics parts store, or radio shack, back when they actually carried electronic components. Now I feel like there are a ton of other options out there, and I don't know if I"m even looking in the right direction. I'm just wanting to get some breadboard and start plugging in components, but maybe that's just oldschool and there's something better out there I don't even know about. There are no shortage of resources about learning the basics, including links here on this forum, but I'm struggling with the practical questions more than the theory.

[ledtester]

An Arduino + seven segment display, e.g.:

LED Displays with Arduino - 7-Segment & Dot-Matrix -- Dronebot Workshop
https://youtu.be/6XY9PooMrms

Once you get the circuit working you can reduce the Arduino to a smaller form factor.

[pcprogrammer]

Or a 16x2 LCD https://www.futurlec.com/LED/LCD16X2.shtml depending on what you want to display.

There are many options available to do displaying, but indeed an Arduino type board is the easiest to start with for doing the counting and the displaying. It can also read the button and start the sound player.

Google is your friend here. Lost of projects with Arduino and a display out there.

If size is of matter, you can get an Arduino nano or a mini. Much smaller then an uno.

[Terry Bites]

Look on ebay or aliexpress- loads of tally counters LCD and LED.
Disect it if you dont like the case.
Why make what you can buy for a few $.
Add a squeaker of choice.
Arduino, LCD diplays etc.... Wasted effort or what!

[fourfathom]

Arduino, LCD diplays etc.... Wasted effort or what!

Sometimes wasted effort isn't really wasted.  The OP did say this:

So we decided we might as well try to make it, and learn something in the process

[Torabi]

I did indeed see plenty of suggestions to use an Arduino... And while they look like great learning tools, they seem like overkill for the project, and way too expensive if we want to make a bunch of the things. The suggestion to buy some cheap tally counters and break them down is probably the most economical, and educational in its own way. I imagine they're probably a single PCB, rather than separate components. While I could probably follow the circuit path back from the speaker, and solder in leads to an external sound chip, I was hoping to have something a little more flexible to play with, to be able to easily add and remove components. If I really wanted something in bulk, I should probably just design something up and find a supplier who will make the whole thing for me, but that takes the educational aspect out of it. Maybe I need to separate the two goals if I'm going to accomplish either.

[ledtester]

What is "way too expensive"? And how many do you expect to build?

Note that you can get an Arduino board for about $5 shipped:

https://www.aliexpress.com/item/3256802812076923.html

I would use the Arduino to prototype and refine your design. Then when you have the design locked down it will be a lot easier to offer pointers on how to make it as cheaply as possible. There are, for example, microcontrollers which only cost a dime a piece, but they aren't exactly easy to work with, so you want to nail down your requirements before you start considering them.

Now, there are dozens of buttons that will record and play back a sound on Amazon for $10+ a pop, ...

Also, check aliexpress for sound modules -- you can probably find some cheaper ones there.

[Torabi]

Oh wow. I'd been looking around on Alibaba and Aliexpress, but hadn't looked there for Arduino boards. The ones I had seen elsewhere ran from $20 to several hundred, so I had disregarded them as an overpriced learning kit. Still, it seems odd to me that the general suggestion seems to be to just program a microcontroller, rather than build a specialized circuit. I guess MCUs have just gotten cheap enough to make that the go-to strategy. I would have expected to do things in hardware, rather than software. I had even started leaning towards a mechanical pulse counter, since I was having so much trouble finding a simple, small digital one!

Why should I buy an MCU and program it, when I could just buy a board off Aliexpress that will record and play back a sound for under $2? Like this one. So I could run the counter off the same chip? I guess since I'm having so much trouble finding a simple counter display... This is pretty much what I'm looking for. I'm just surprised I can't find others, particularly for cheaper than I could just buy a bunch of tally counters. I guess I expect parts to be cheaper than a finished product.

I was planning on making a few dozen of them, and if people found them sufficiently amusing, try finding a manufacturer to mass produce them and sell them.

[nvmR]

You could go for the board that you suggested, but it could run you into a few issues.
The board is preprogrammed, so you can't modify the code. Also, a schematic isn't available, so it would be hard to debug.

I would recommend that you get some Arduinos (which can do the job you need + much more), the board you suggested, some speakers, etc, and play around with it for a bit. Get a working product built, and then optimize for production, whether it be based on Arduino, a custom board based on an Atmel MCU, or the board you suggested.

In any case, buying a ready made board, is getting 3cents of CPU in a 2$ package. Any dedicated board will be much cheaper, but you will have to put in the NRE work.

Best of luck