Simple Audio Module

[electrousa]

Hello There,

I want to make a board which will take an AUDIO source (for example a mp3 source) as input and output to drive a small speaker (could be dynamic speaker used in laptop).

I know I at least need a Speaker Amplifier to drive the speaker. But that is all I know now.

Anybody can give me a clue on how to build such a module?
What components (parts) will be needed?

Thanks in advance!

 

[WTP Pepper]

Google TDA2004. They are general purpose Audio amp ICs. Also try TBA820M.

 

[electrousa]

What about the input side of the audio amp ICs? What kind of ICs I should use? up to the finally input of MP3 source.

 

[audioguru]

You don't need another IC unless you want to add bass and treble tone controls.

 

[4pyros]

Look up pocket amp. Some have been made to drive speakers.

 

[electrousa]

You don't need another IC unless you want to add bass and treble tone controls.

Thanks Audioguru! Thanks guys!

My board is an embedded module with an ATMEL's Mirco-controller. My idea is to find a audio IC which has internal memory to storage the audio data and serial port for communication between the Micro-controller and the Audio IC.

Any suggestion?

 

[WTP Pepper]

You are not clear as to if you need an audio amp (simple solution) or an embedded mp3 codec with a host AVR as a controller (not simple).

 

[misterT]

You are not clear as to if you need an audio amp (simple solution) or an embedded mp3 codec with a host AVR as a controller (not simple).

Check out http://www.atmel.com/Microsite/audio/default.aspx

 

[electrousa]

You are not clear as to if you need an audio amp (simple solution) or an embedded mp3 codec with a host AVR as a controller (not simple).

I have no knowledge about audio design.

I have a design done with Atmel's ATMEGA16L-8AU(AVR MCU 16K 8MHZ 3V 44TQFP) and I was asked to add an audio function into the exist design to play sound. Don't know if there has a codec IC with internal memory for storing sound track data so that I don't have to change the MCU and the existing MCU can directly manages the audio IC.

Anyway, the better solution will be the first to think.

 

[Gobbledok]

What are you using it for?

Are you (for example) playing MP3's from an SDcard?

Or do (for example) want some basic sounds which you can play under certain conditions (sound effects).

 

[electrousa]

What are you using it for?

Are you (for example) playing MP3's from an SDcard?

Or do (for example) want some basic sounds which you can play under certain conditions (sound effects).

It is going to be used in display module for elevator to indicate some simple status (like up and down and play with sound effects).

 

[electrousa]

What are you using it for?

Are you (for example) playing MP3's from an SDcard?

Or do (for example) want some basic sounds which you can play under certain conditions (sound effects).

The board will be using for simply display and play some kind of sound effects in elevator peripheral unit.

 

[misterT]

You could store the audio samples in a flash memory and then play them using PWM. The audio format cannot be mp3, but you can easily convert your audio samples to more "usable" format. here are some links:
https://www.romanblack.com/picsound.htm
https://www.electro-tech-online.com/custompdfs/2012/02/doc1456.pdf
https://avrpcm.blogspot.com/2010/11/playing-8-bit-pcm-using-any-avr.html

I have heard about chips that decode and play mp3 stream, but could not find any now.
EDIT: Found this: https://www.pjrc.com/mp3/sta013.html

 

[electrousa]

Thanks misterT for the great information. I studied the links and still have some questions on that.

Though an AVR micro controller can generate PWM signal and drive speaker directly, I may need a speaker amplifier to drive a more powerful speaker (lets say 2W).

Is there a speaker amplifier chipset supports PWM signal as input? Because when I searched the speaker amplifier chipset I noticed they generally support digital or analog input. I don't know if I can treat the PWM signal as digital signals here?

In the case of no PWM input speaker amplifier, what should I do to use convert PWM signal to digital/analog signals required by the speaker amplifiers?

 

[misterT]

What should I do to use convert PWM signal to digital/analog signals required by the speaker amplifiers?

You must use a low-pass filter (RC-filter) to "smooth out" the PWM. The result is an analog audio signal which you then feed to analog amplifier.

View attachment 61162

 

[electrousa]

You must use a low-pass filter (RC-filter) to "smooth out" the PWM. The result is an analog audio signal which you then feed to analog amplifier.

View attachment 61162

Thanks you!