NAME

miri_fm - a simple narrow band FM demodulator for Mirics based receivers

DESCRIPTION

Software for the Mirics MSi2500 + MSi001 SDR platform

written because people could not do real time FM demod on Atom hardware with GNU radio based on rtl_sdr.c and rtl_tcp.c

USAGE

This program captures information from a band of frequencies and outputs the data in a form useful to other software radio programs.

SYNOPSIS

miri_fm [-f freq] [OPTIONS] [output file]

OPTIONS

-f frequency_to_tune_to [Hz]
use multiple -f for scanning (requires squelch)
ranges supported, -f 118M:137M:25k
-M modulation (default: fm)
fm, wbfm, raw, am, usb, lsb
wbfm == -M fm -s 170k -o 4 -A fast -r 32k -l 0 -E deemp
raw mode outputs 2x16 bit IQ pairs
-s sample_rate (default: 24 kHz)
-d device_index (default: 0)
-T device_type device variant (default: 0)
0: Default
1: SDRPlay
-g tuner_gain (default: automatic)
-m sample format (default: auto)
504: S8 (fastest)
384: S10 +2bits
252: S14
-e USB transfer mode (default: 1)
1: Isochronous (maximum 196.608 Mbit/s)
2: Bulk (maximum 333Mbit/s, depends on controller type)
-i IF mode (default: ZERO)
0: ZERO
450000: 450 kHz
1620000: 1620kHz
2048000: 2048kHz
-w BW mode (default: 8MHz)
200000: 200kHz
300000: 300kHz
600000: 600kHz
1536000: 1536kHz
5000000: 5MHz
6000000: 6MHz
7000000: 7MHz
8000000: 8MHz
-l squelch_level (default: 0/off)
-o oversampling (default: 1, 4 recommended)
-p ppm_error (default: 0)
-E enable_option (default: none)
use multiple -E to enable multiple options
edge: enable lower edge tuning
dc: enable dc blocking filter
deemp: enable de-emphasis filter
direct: enable direct sampling
offset: enable offset tuning
filename ('-' means stdout)
omitting the filename also uses stdout

EXPERIMENTAL OPTIONS

-r resample_rate (default: none / same as -s)
-t squelch_delay (default: 10)
+values will mute/scan, -values will exit
-F fir_size (default: off)
enables low-leakage downsample filter
size can be 0 or 9. 0 has bad roll off
-A std/fast/lut choose atan math (default: std)

EXAMPLES

Produces signed 16 bit ints, use Sox or aplay to hear them.
miri_fm ... | play -t raw -r 24k -es -b 16 -c 1 -V1 -
| aplay -r 24k -f S16_LE -t raw -c 1
-M wbfm | play -r 32k ...
-s 22050 | multimon -t raw /dev/stdin

If the device can't be opened, make sure you have the appropriate rights to access the device (install udev-rules from the repository, or run it as root).

AUTHOR

This manual page was written by Maitland Bottoms for the Debian project (but may be used by others).

COPYRIGHT

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.