Can someone please explain to me the basic steps involved in transferring a file via sound wave and receiving it on the other end and converting it back to a file? Is it like the following:

File --> convert to binary --> digital to analog converter --> Play the sound file --> receive the sound file via microphone on other computer --> analog to digital converter --> convert from binary to file

Are these the steps involved?

Please help!

Thank you!

 

A 3.5mm stereo - 3.5mm stereo cable should work. Plug the sending end into that sound card output (headphone) and the receiving end to the other sound card's line input. You will need a media player to send the file, and something like Audacity (freeware app) to receive it.

A thumb drive works for longer distances, should always be error free, and transfer the file (already in binary whether in WAV, MP3, OGG, or whatever) much faster.

 

No but we have to do this without any wires or anything of that sort. We have to do it in this program called MATLAB too. So this program needs to take a file, convert it to sound, play the file, and then other laptop will hear it using its microphone, convert it back to a file. I just want to know the general steps in taking a file and converting it to sound file. How do you do that? Is it even possible? Can you play it after you've converted it??

 

Cool. Never thought of that but I suppose it can be done. You have to come up with a modulation scheme, like they did with cassette recorders back in the good old days. Google "Kansas City Standard".

And make a note of the names of the participants at that Byte gathering!

 

A 3.5mm stereo - 3.5mm stereo cable should work. Plug the sending end into that sound card output (headphone) and the receiving end to the other sound card's line input. You will need a media player to send the file, and something like Audacity (freeware app) to receive it.

A thumb drive works for longer distances, should always be error free, and transfer the file (already in binary whether in WAV, MP3, OGG, or whatever) much faster.

Beenthere! You've been-wherever, and now you're back! welcome back!
(sorry for the hijack)

 

Hello,

It is possible but will be very slow.
Think of the analog modems of the old days.
Normaly they managed 9600 Bps.
With a special modulation scheme they managed 56 kBps.

You can read more about digital modulation schemes here:
http://www.educypedia.be/electronics/rfdigmod.htm

Bertus

 

Wait a second...receiving the digital file using microphone. I don't think it might be possible as in air where the sound will travel will have noise and other sound signals unless of some special areas like recording studio. These signals will be also picked up by the microphone and the original data will mixed up with the noise and other sound signals so you will loose the integrity of the data.

Anyway I didn’t tried ever, you could give it a try....

[EDIT]
Sound scheme was used long ago to do this kind of stuff not for digital files but for information known as telegraph... it used Morse code which used a high frequency tone for the data elements so noise couldn’t interfered.
These days I am learning Morse code as planning to get a HAM license ,the sounds are really irritating....

Good Luck

 

Hey guys thanks for all the replies.

I will read a textfile into the program, split the whole file up into individual characters and apply a tone to each character like how it is in morse code, and then the other laptop will pick it up and record it back into a file. I hope this is possible as this is our project for school and I don't think integrity of data matters much. We just have to show that we can transmit data from one laptop to another via soundcard. Thanks!

 

PSK can do the tick, some hams sites have source codes for psk medem.

 

Reminds me of the old magnetic tape drives...technology that has been obsolete since the 1980s. The sound the microphone will have to pick up will probably be like the handshake burst tones you hear when you call a fax line. It was useful at one time, but advances in technology offer much more efficient and error-free ways of transferring data.

 

Nevermind, got it.

 

read in file, encode it, save as wav, play sound
on receiving end record the sound, filter, decode, write file.

this is only proof of concept so data rate is irrelevant.
you can use FM or PM to reduce interference. PM or PSK is used in digital communication.
AM can work too but it will be very sensitive to noise.

 

Paired tones are used for telephone signalling (dialling). This is a very robust system, albeit slow. Perhaps it would be too complex for you to realise, but it might just make it through the classroom interference.

http://en.wikipedia.org/wiki/Dual-tone_multi-frequency_signaling