.TH "miri_fm" 1 "2.0.0" MiriSDR "User Commands"
.SH NAME
miri_fm \- a simple narrow band FM demodulator for Mirics based receivers
.SH DESCRIPTION
Software for the Mirics MSi2500 + MSi001 SDR platform
.LP
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
.SH USAGE
This program captures information from a band of frequencies
and outputs the data in a form useful to other software radio
programs.
.SH SYNOPSIS
.B  miri_fm [-f freq] [OPTIONS] [output file]
.SH OPTIONS
.IP "-f frequency_to_tune_to [Hz]"
.IP "   use multiple -f for scanning (requires squelch)"
.IP "   ranges supported, -f 118M:137M:25k"
.IP "-M modulation (default: fm)"
.IP "   fm, wbfm, raw, am, usb, lsb"
.IP "   wbfm == -M fm -s 170k -o 4 -A fast -r 32k -l 0 -E deemp"
.IP "   raw mode outputs 2x16 bit IQ pairs"
.IP "-s sample_rate (default: 24 kHz)"
.IP "-d device_index (default: 0)"
.IP "-T device_type device variant (default: 0)"
.IP "   0:       Default"
.IP "   1:       SDRPlay"
.IP "-g tuner_gain (default: automatic)"
.IP "-m sample format (default: auto)"
.IP "   504:    S8 (fastest)"
.IP "   384:    S10 +2bits"
.IP "   252:    S14"
.IP "-e USB transfer mode (default: 1)"
.IP "   1:      Isochronous (maximum 196.608 Mbit/s)"
.IP "   2:      Bulk (maximum 333Mbit/s, depends on controller type)"
.IP "-i IF mode (default: ZERO)"
.IP "   0:       ZERO"
.IP "   450000:  450 kHz"
.IP "   1620000: 1620kHz"
.IP "   2048000: 2048kHz"
.IP "-w BW mode (default: 8MHz)"
.IP "   200000:  200kHz"
.IP "   300000:  300kHz"
.IP "   600000:  600kHz"
.IP "   1536000: 1536kHz"
.IP "   5000000: 5MHz"
.IP "   6000000: 6MHz"
.IP "   7000000: 7MHz"
.IP "   8000000: 8MHz"
.IP "-l squelch_level (default: 0/off)"
.IP "-o oversampling (default: 1, 4 recommended)"
.IP "-p ppm_error (default: 0)"
.IP "-E enable_option (default: none)"
.IP "   use multiple -E to enable multiple options"
.IP "   edge:   enable lower edge tuning"
.IP "   dc:     enable dc blocking filter"
.IP "   deemp:  enable de-emphasis filter"
.IP "   direct: enable direct sampling"
.IP "   offset: enable offset tuning"
.IP "filename ('-' means stdout)"
.IP "         omitting the filename also uses stdout"
.SH EXPERIMENTAL OPTIONS
.IP "-r resample_rate (default: none / same as -s)"
.IP "-t squelch_delay (default: 10)"
.IP "   +values will mute/scan, -values will exit"
.IP "-F fir_size (default: off)"
.IP "   enables low-leakage downsample filter"
.IP "   size can be 0 or 9.  0 has bad roll off"
.IP "-A std/fast/lut choose atan math (default: std)"
.SH EXAMPLES
.IP "Produces signed 16 bit ints, use Sox or aplay to hear them."
.IP "miri_fm ... | play -t raw -r 24k -es -b 16 -c 1 -V1 -"
.IP "            | aplay -r 24k -f S16_LE -t raw -c 1"
.IP "   -M wbfm  | play -r 32k ..."
.IP "   -s 22050 | multimon -t raw /dev/stdin"
.LP
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).
.SH SEE ALSO
miri_sdr(1)
.SH AUTHOR
This manual page was written by Maitland Bottoms
for the Debian project (but may be used by others).
.SH COPYRIGHT
Copyright (c) 2023 A. Maitland Bottoms <bottoms@debian.org>
.LP
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.
.LP
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.