Difference between revisions of "Simple FM transmitter using gnuradio"

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Line 4: Line 4:
 
*gnuradio 3.2
 
*gnuradio 3.2
 
*grc (gnuradio companion)
 
*grc (gnuradio companion)
 +
*mpg123
 
*USRP
 
*USRP
  
GRC Schema:
+
Mono FM transmission is very simple as all necessary blocks already exist in gnuradio.
 +
In this example we will show how to make a FM transmission from an mp3 stream for an Internet radio.
 +
 
 +
==GRC Schema==
 
[[Image:FM transmitter FIFO.png]]
 
[[Image:FM transmitter FIFO.png]]
 +
 +
Input file is a unix FIFO file that means that we need to feed it externally from the shell using these commands
 +
 +
Creation of the FIFO file (once):
 +
mkfifo stream_32k.fifo
 +
 +
Decoding of an mp3 Internet radio station stream, conversion and output of raw linear samples to the FIFO:
 +
mpg123 -r32000 -m -s  http://maxxima.mine.nu:8000 >stream_32k.fifo
 +
 +
Option "-m" is to convert stream to mono, "-r32000" perform sample rate conversion to 32kHz.

Revision as of 18:56, 2 January 2010

Simple FM transmitter using gnuradio.

Tools needed:

  • gnuradio 3.2
  • grc (gnuradio companion)
  • mpg123
  • USRP

Mono FM transmission is very simple as all necessary blocks already exist in gnuradio. In this example we will show how to make a FM transmission from an mp3 stream for an Internet radio.

GRC Schema

FM transmitter FIFO.png

Input file is a unix FIFO file that means that we need to feed it externally from the shell using these commands

Creation of the FIFO file (once):

mkfifo stream_32k.fifo

Decoding of an mp3 Internet radio station stream, conversion and output of raw linear samples to the FIFO:

mpg123 -r32000 -m -s  http://maxxima.mine.nu:8000 >stream_32k.fifo

Option "-m" is to convert stream to mono, "-r32000" perform sample rate conversion to 32kHz.