Simple FM transmitter using gnuradio
From Opendigitalradio
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Revision as of 19:56, 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
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.
