Minimal, small, sound player module (toy/novelty)?

Thread Starter

KeithManiac

Joined May 14, 2014
2
Intro: I'm currently working on the next phase of a top secret art project, which just passed the threshold of the prototype stage. I'm building an electronic project that involves light and sound; the initial prototype consisted of a sound module rigged into an LED circuit, so that it lights up whilst making noises via a pushbutton incorporated in the whole series. Think of it as a custom toy or a fan prop, and I intend on building multiples and selling them at cons. I've searched all around the internet as well as this particular site, but got only mixed answers.

What I'd like to know, plain and simple, is how I can go about constructing a very small, minimal sound player which plays a small sound effect when triggered -- like a .5 second WAV file, about 16 KBytes or so. Think of the tiny sound box inside a pull-string doll or an action figure, but without the need for SD cards, and instead uses a small flash storage chip.

But first, I must make a few things clear:

1) The prototype circuit I made was built from a custom 555 IC one-shot timer I designed which was attached in a parallel circuit with a hacked Radio Shack 9V sound recorder I bought. I've actually already built and tested a crude sound player using a Radio Shack sound recorder (similar to a greeting card recorder) and my aforementioned 555 IC breadboard, but since the Radio Shack sound product has no schematic nor Eagle file, I'm unable to replicate it via PCB printing (and plus, it's definitely not open source). The prototype project is fully functional, and now I'm looking to build several more of these projects en masse by getting custom PCBs printed, rather than painstakingly hacking apart more sound modules and crudely rigging them into more 555 circuits. I'd like to make a PCB of one circuit of both the sound and LED together on one chip, completely integrated. I'm working on getting the PCB made from 123Dcircuits.com, but again, only LED portion is documented by me and able to be printed -- the sound module on the other hand is what I'm specifically seeking to learn to build from scratch.

2) Rather than using an SD card (which is how 95% of the schematics I've seen online work), I'd like to have the small .WAV file stored in a tiny flash memory chip, like a 64 KByte flash memory chip or likewise.

3) For transferring the sound to the chip, I'd prefer to either use a USB (micro/mini) input or a 3.5mm audio jack, rather than an external mic as in the Radio Shack recorder. I've seen some things online for making rudimentary sound players just like this which used an Arduino to add the sound to the chip, but MIDI sounds rather than WAV files.

4) The power supply isn't really important for now; after all, this particular sound module will be in parallel with the LED module I've already mapped out, and in the prototype, the whole thing was powered successfully with a 9V battery or 4 AAAs.

5)The sound will be played via a small 8 Ohm speaker. In the prototype, this is already soldered into the preexisting sound module I bought at Radio Shack. The sound wasn't spectacular, but it got the job done, especially considering it was a small novelty item.

Again, I'd like to know how I could make the simplest, easiest sound player for playing short sound clips -- think of something like a greeting card or a Staples Easy button. I'd like the design to be as minimal as possible, with just the necessary microcontroller, RAM chip, resistors, capacitors, switch, et alia -- nothing too fancy -- so that I can incorporate this small circuit into the second layer of my LED circuit to be printed on a PCB (which is specifically why I'm not going to buy a bunch of audio greeting cards and hack apart their sound modules)!

I did in fact check this site, and I found a project here which is almost verbatim to what I'm looking to build -- except mine blasts one sound, instead of two.

Also, here's a product I found online which is essentially what I'd like to make -- but, this particular audio player in the link has an SD card slot instead of a flash memory chip (I'm not sure, but is it possibly to basically copy this circuit and somehow swap out the SD card slot on the schematic and replace it with a small flash storage chip, along with some minor adjustments?). Otherwise, this is basically what I have in mind: small, barebones, and not too elaborate.

If you fellas could help me out and please provide to me the most basic audio player circuit in either a schematic format or an Eagle file, I'd be very grateful indeed! Again, my prototype of rigging a preexisting Radio Shack sound player to my homemade LED circuit is a success -- and now I'd somehow like to combine both into a single chip for making several custom PCBs. I'm using 123D Circuits to make cheap, small printed circuits on demand. Size is also an issue, so ideally I'd like to have the circuit around 4-5 cm in width, and about 2-3 cm in length -- like, really stupid simple small! I'm vaguely familiar with 555 ICs and ATTiny85 chips, in case you have any small sound projects that use those.

If you need anymore information about what my ideal circuit should require, I'll be glad to provide more without leaking too much of my secret project!

Thanks!
 

wayneh

Joined Sep 9, 2010
17,498
Without divulging anything about the secret nature of your project, it would be very helpful if you could supply a schematic or at least a block diagram of what you're planning. It's great that you supplied so much detail in your text, but the shear length of it may turn some away. A picture gets more feedback, in my opinion.

As far as I can see, the electronics of your project are nothing proprietary or "secret" at all, so we should be fine as long as we focus on the specifications; power source, desired sound volume, playback quality and length, size, cost, etc. Thanks for supplying so much of this already.
 

BobTPH

Joined Jun 5, 2013
8,961
I would use a PIC24FJ32MC101. It is a 20-pin chip with 32K bytes of program memory, most of which you would use to store the sound(s). You could use a full-bridge PWM signal to output the sound using 4 SMT mosfets to make the bridge and that would be able to drive a speaker directly. Cost in quantity is $1.68. The PWM resolution is 16-bit so it should produce quite good sound.

bob
 

Thread Starter

KeithManiac

Joined May 14, 2014
2
I would use a PIC24FJ32MC101. It is a 20-pin chip with 32K bytes of program memory, most of which you would use to store the sound(s). You could use a full-bridge PWM signal to output the sound using 4 SMT mosfets to make the bridge and that would be able to drive a speaker directly. Cost in quantity is $1.68. The PWM resolution is 16-bit so it should produce quite good sound.

bob
I think I have an idea what you're talking about. Would I need anything else in particular, like resistors, transistors, capacitors, and whatnot? Also, in this case, how would I go about adding the sound to the 20-pin chip?

Thanks!
 

BobTPH

Joined Jun 5, 2013
8,961
I think you could actually do it with just the PIC, 1 capacitor, your button and 1 resistor, and 4 mosfets. The mosfets would have to be logic level ones which turn on fully at 3.3V which is the voltage used by the microcontroller. There is another model that runs at 5V which might be better because it is easier to find mosfets that are on at 5V than at 3.3V.

The chip is a microcontroller, which needs to be programmed. You would store the sound as part of the program. If you are not already fluent in microcontroller programming, it is a lot to learn, but doable if you are motivated.

Bob
 
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