Play .wav using uC

[arybinsky]

Hi,
I am designing a mobile robot based on AT91SAM7S64 microcontroller. I
want the robot to emit
sound from .wav files. Nothing fancy, 8-bit 11khz mono wavs. Let's say
I will handle reading/decoding the .wav files from SD card. What
remains is the sound emission - I'll probably need a DAC and some kind
of AMP to drive the little 8 Ohm speaker. I'd be happy if the solution
was simple as possible and not very costly. The 3.3v supply is
available (Battery -> DC/DC converter). What design would you
recommend?

Cheers,
Alexiey

 

[CosteC]

I am designing a mobile robot based on AT91SAM7S64 microcontroller. I

want the robot to emit
sound from .wav files. Nothing fancy, 8-bit 11khz mono wavs. Let's say
I will handle reading/decoding the .wav files from SD card. What
remains is the sound emission - I'll probably need a DAC and some kind
of AMP to drive the little 8 Ohm speaker. I'd be happy if the solution
was simple as possible and not very costly. The 3.3v supply is
available (Battery -> DC/DC converter). What design would you
recommend?

If you have free DAC use it. With some simple filter and power amp (to drive
this 8 Ohm speaker) results should be nice.
You can also try use PWM driver (but PWM frequency should be high: around
100kHz) You can also try drive speaker with PWM signal (of course though
power stage - but this power stage can be digital)

Best Regards
CosteC

 

[jasen]

Hi,
I am designing a mobile robot based on AT91SAM7S64 microcontroller. I
want the robot to emit
sound from .wav files. Nothing fancy, 8-bit 11khz mono wavs. Let's say
I will handle reading/decoding the .wav files from SD card. What
remains is the sound emission - I'll probably need a DAC and some kind
of AMP to drive the little 8 Ohm speaker. I'd be happy if the solution
was simple as possible and not very costly. The 3.3v supply is
available (Battery -> DC/DC converter). What design would you
recommend?

if you have a spare counter in the chip have you considered PWM for the
DAC.

I got reasonable results running a DDS to the PWM harvare in an AT90S2313.
I ran 4 DDS on a 10Mhz chip though its internal 8-bit PWM (19.6Khz sanmple
rate) and got polyphonic muzak.

if you've got wav files you just need to stretch them to the sample rate of
your PWM, and apply a low pass filter somewhere between the chip and the
loudspeaker

Bye.
Jasen

 

[arybinsky]

if you've got wav files you just need to stretch them to the sample rate of
your PWM, and apply a low pass filter somewhere between the chip and the
loudspeaker

Bye.
Jasen

Thanks for the answers - one more thing - how to design the power
stage most simply?

 

[Henry Kiefer]

TDA7052 or TDA7052A
The A-version includes an analog speaker volume control input.

If you need some, drop me a line.

regards -
Henry


--
www.ehydra.dyndns.info


|
| > if you've got wav files you just need to stretch them to the sample rate of
| > your PWM, and apply a low pass filter somewhere between the chip and the
| > loudspeaker
| >
| > Bye.
| > Jasen
|
| Thanks for the answers - one more thing - how to design the power
| stage most simply?
|

 

[arybinsky]

TDA7052 or TDA7052A
The A-version includes an analog speaker volume control input.

Great, that's exactly what I need. But do you know anything similar in
SMD packages?

 

[Henry Kiefer]

The TDA7052AT is what you want. The same die in a SO-8 package.

I can offer them. Drop me a private message with where you live and quantity.

regards -
Henry

--
www.ehydra.dyndns.info


| > TDA7052 or TDA7052A
| > The A-version includes an analog speaker volume control input.
|
| Great, that's exactly what I need. But do you know anything similar in
| SMD packages?
|

 

[arybinsky]

The TDA7052AT is what you want. The same die in a SO-8 package.

I can offer them. Drop me a private message with where you live and quantity.

Thanks for the answer. I need only two of them, however, but anyway
thanks for the offer
A

 

[Henry Kiefer]

| > The TDA7052AT is what you want. The same die in a SO-8 package.
| >
| > I can offer them. Drop me a private message with where you live and quantity.
|
| Thanks for the answer. I need only two of them, however, but anyway
| thanks for the offer

You're wellcome.

- Henry