Hi every one,,,
I used to navigate this forum once in a while to explore the ideas of the members, but now I am facing a problem in an electronic circuit I designed.

Well I want to store a sound file in an EPROM M5L2764 which can hold up to 8k bytes of data and then play the sound file using DAC0808 with a LPF and an opamp.

I used 14 bit counter connected as the address of the EPROM
and the data coming out of the EPROM is exactly the one shown in the HEX representation of the file using HEX Probe editor.

Further more the DAC0808 workes perfectly except that all what I hear is noise even though I varied the frequency of the counter from 1 kHz to 1MHz.

Does anybody know what is the problem? I personally suspect that the data from the file is not the actual representation of the sound!

 

How are you recording the sound to the file? You will need to use the same coding method and speed when you take it out of the EPROM. Does the runtime of the noise run the same amount of time that the recording it supposed to be? That will tell you if speed is an issue.

 

If you don't use compression software, an old 2764 will hold about 1 second of very poor quality audio.

__________________
Uncle $crooge

 

How did you record the sound data ?

What method did you use to program the EEPROM ?

 

thank you guys for replying.
well i just got the file from the net, its a normal 16 kbyte file (4 seconds). so should I use a compression software? and how to edit the file so I can have sampling rate of 8 bits/sample?

 

16kbytes in 4 seconds is a sampling rate of 4kbytes per second which is terrible. Have you ever heard an underwater throat microphone?

Its sampling rate is selected for the recording. It must be compressed during the recording. It is too late to change them now.

__________________
Uncle $crooge

 

You are probably trying to play back a 16bit Stereo sound sample. Convert it to 8bit mono first and make sure it is a WAV file. You may also have to reduce the bit-rate to make it fit in the 8K space of your EEprom. You also should strip off the first (I think it is a 46 byte header) few bytes of the WAV file because they just contain sample rate info etc.

__________________
--- The days of the digital watch are numbered. ---

 

Maybe the sound is just, "POP" and he blinked and missed hearing it.

__________________
Uncle $crooge

 

If he clocks it slow enough the cymbals can sound like Bass
But it IS possible. About 15yrs ago I made a talking eggtimer out of a 32K Eprom, R-2R network and some 4000 series logic... Here is a sample which is coded at 6K per second. And yes, I made the chicken sound although it is speeded up a bit to increase the pitch:

Attached Files

EGGTIMER.zip (21.0 KB, 14 views)

__________________
--- The days of the digital watch are numbered. ---

 

The Egg Timer sounds pretty good for such a low rate.
I heard long distance telephone at 8k per second and it sounded awful.

__________________
Uncle $crooge

 

Oh guys I have done It!
The trick was in the coding.
I used a software called wavepad to create a sound file with sampling rate of 8 kbyte/s 8 bits-MONO using PCM coding and it works fine. It plays 1 second of medium quality sound.
Thanks guys...

 

I was right. "POP" is about one second long.

__________________
Uncle $crooge