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minimodem: --rx same (NOAA SAME protocol)

This commit is contained in:
Kamal Mostafa 2012-09-01 13:34:50 -07:00
parent 04cc215640
commit 9187dd60a7
2 changed files with 28 additions and 7 deletions
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18
src/minimodem.1.in
View File

@ -129,11 +129,14 @@ Run and report internal performance tests (all other flags are ignored).
print program version print program version
.SH {baudmode} .SH {baudmode}
The required \fI{baudmode}\fR parameter may be any floating-point value to The required \fI{baudmode}\fR parameter may be any floating-point value to
specify a baud rate, or the string "rtty". specify a baud rate, or either of the strings "rtty" or "same".
The \fI{baudmode}\fR also implies certain other parameter defaults The \fI{baudmode}\fR also implies certain other parameter defaults
depending on the rate, including standard (or at least reasonable) depending on the rate, including standard (or at least reasonable)
default mark and space tone frequencies. default mark and space tone frequencies.
.TP .TP
.B {any floating point value N}
: Bell-syle N bps \-\-ascii
.TP
.B 1200 .B 1200
: Bell202 1200 bps \-\-ascii : Bell202 1200 bps \-\-ascii
.TP .TP
@ -143,8 +146,10 @@ default mark and space tone frequencies.
.B rtty .B rtty
: RTTY 45.45 bps \-\-baudot \-\-stopbits 1.5 : RTTY 45.45 bps \-\-baudot \-\-stopbits 1.5
.TP .TP
.B {any floating point value N} .B same
: Bell-like N bps \-\-ascii : SAME 520.83 bps \-\-startbits 0 \-\-stopbits 0 \-\-sync-byte 0xAB
.br
NOAA Specific Area Message Encoding (SAME) protocol
.SH EXAMPLES .SH EXAMPLES
.TP .TP
.B minimodem --tx 100 .B minimodem --tx 100
@ -153,9 +158,14 @@ Transmit 100 baud tones from one computer ...
.B minimodem --rx 100 .B minimodem --rx 100
and receive 100 baud tones on another nearby computer. and receive 100 baud tones on another nearby computer.
.TP .TP
.B minimodem --rx --auto-carrier rtty .B minimodem --rx -a rtty
Decode amateur radio RTTY signals (listen near 14.085 MHz). Decode amateur radio RTTY signals (listen near 14.085 MHz).
.TP .TP
.B minimodem --rx same
Decode NOAA SAME protocol emergency alert transmissions, e.g.
.br
http://en.wikipedia.org/wiki/Specific_Area_Message_Encoding
.TP
.B minimodem --tx 0.5 .B minimodem --tx 0.5
Experiment with very low baud rates (works in noisy conditions). Experiment with very low baud rates (works in noisy conditions).
.TP .TP

11
src/minimodem.c
View File

@ -563,6 +563,17 @@ main( int argc, char*argv[] )
bfsk_n_data_bits = 5; bfsk_n_data_bits = 5;
if ( bfsk_nstopbits < 0 ) if ( bfsk_nstopbits < 0 )
bfsk_nstopbits = 1.5; bfsk_nstopbits = 1.5;
} else if ( strncasecmp(modem_mode, "same",5)==0 ) {
// http://www.nws.noaa.gov/nwr/nwrsame.htm
bfsk_data_rate = 520.0 + 5/6.0;
bfsk_n_data_bits = 8;
bfsk_nstartbits = 0;
bfsk_nstopbits = 0;
bfsk_sync_on_data = 1;
bfsk_sync_byte = 0xAB;
bfsk_mark_f = 2083.0 + 1/3.0;
bfsk_space_f = 1562.5;
band_width = bfsk_data_rate;
} else { } else {
bfsk_data_rate = atof(modem_mode); bfsk_data_rate = atof(modem_mode);
if ( bfsk_n_data_bits == 0 ) if ( bfsk_n_data_bits == 0 )