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).

SEE ALSO

       miri_sdr(1)

AUTHOR

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

COPYRIGHT

       Copyright (c) 2023 A. Maitland Bottoms <bottoms@debian.org>

       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.