Record and play fast 1bit sound on a PIC!

Willie Erasmus · Guest

Hi

Has anybody out there tried to implement sound on a PIC as Roman Black did. Have a look at the followimg site of Roman Black. He did a great job for implementing his technique of sound generation.

<a href="http://www.romanblack.com/picsound.htm" TARGET="_blank">http://www.romanblack.com/picsound.htm</a>

Any comments?

Willie

The software on his site doen's work but he mailed me a newer version. Interested, drop me an email for the newer version.
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Original Post ID: 10087

arl · Guest

Hi,

I will try to do this project in the next days. I will try to work with a piezo bepper instead a speaker (I will be able to play voice files?...).

Encoder.exe not work fine in XP environments, can you send me the latest versión?

Thanks

alvaro.rivas@gmail.com

Yoz · Joined: 15 Mar 2005 Posts: 1

I've been experimenting with this concept. I couldn't get the encoder.exe program to work on computers running Win95 to WinXP. I emailed the author back on 2/22/05 and never received a reply.

So, I ended up writing my own encoder program minus the graphic output.

The idea sort of works. Direct driving the speaker with the RC network distorts the waveform resulting in poor sound quality. Feeding the RC output to an amplifier input (such as your PC amplified speakers) keeps the waveform clear.

In my case, I was opting for slower sample rate (4882 Hz) to increase the length of the recording. At 4882 Hz I can get 45 seconds of music in less than 28 kbytes of flash in a PIC18F452.

The last remaining problem is with silence or dead time in the wav file. The 1 bit encoding method will toggle between a 1 and a 0 to maintain a constant level (like during the silent portions between spoken words). This toggling results in an annoying tone being generated in bursts during playback.

I'd be interested in a working copy of the original author's encoder program to compare my output file with his to see if I screwed up the encoding. Please email the encoder program (zip it or change the exe extension to make it past email filters) to:

wesolojw@nv.doe.gov

Thanks.

Guest · Posted: Tue Mar 15, 2005 2:55 pm

hobiadami · Joined: 17 Oct 2006 Posts: 35 Location: City of Concrete

Roman Black seems to improve the concept a bit. Now a new windows software can be downloaded from his website. He is also selling a small card that generates 1 bit sounds.

This is good news.

But it is sad after all these years, I still didn't heard of anyone who actually has managed to duplicate his work and generated sound on the pic micro enviironment. :(
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