RS-232 Recording Audio?

[Ozzyjim]

Gday,

Just thinking - has anyone developed a program to record audio from a scanner via a RS-232 port??.. The olny reason why I am asking is that it would seem logical to record in a uncompressed format from the baseband audio for later signal processing or decoding etc... I am aware that day long recordings could not be done this way but for just a few minutes it should be ok...

Any Thoughts???

 

[ka3jjz]

I doubt it - the RS232 signal is not designed to carry audio. As for baseband audio - you can take the audio signal and change it to a RS232 signal that can be read, but there you are reading signal levels. That is the basic purpose of a data slicer, which is needed by certain decoding packages.

You're kinda mixing apples and oranges here 73 Mike

 

[Ozzyjim]

Ooops - yeah - kinda forgot to expand on my op - I meant feed the baseband signal to a data slicer and "record" the serial data for playback... It would mean that a seperate player would be needed if audio was recorded to "reconstruct" the data...

 

[gmclam]

Usb -> rs-232

I am very big on RS-232 ports and write a lot of apps that use them, but this one does not sound like something good to me. Lots of issues, especially speed/bandwidth.

If you find an app that does this with USB that suits your needs, then get yourself a USB to COM converter and I think you will essentially have what you are looking for.

 

[Ozzyjim]

Gday gmclam,


Wouldn't a USB-RS232 converter still be limited to RS232 speeds due to the RS232 driver IC???....I will also have to go and research the baudrate needed for speech... I should think it would be the same or less than in a P-25 system due to the fact the voice is sent in tha data packets...

 

[gmclam]

Wouldn't a USB-RS232 converter still be limited to RS232 speeds due to the RS232 driver IC???

I'm sure there's a limit, but we're probably talking something like 230k baud. No different than if you had an application that directly communicated with the (RS-232) COM port.

I will also have to go and research the baudrate needed for speech... I should think it would be the same or less than in a P-25 system due to the fact the voice is sent in tha data packets...

Are you sending "raw data" or compressed data? What is the sample rate of the data? What kind of compression? Note that those of us who stream audio to RR from scanners are doing so at 16k bits per second. That is not very fast and could be done at 19.2k baud over a RS-232 channel.