direwolf/morse.c

382 lines
7.8 KiB
C

//
// This file is part of Dire Wolf, an amateur radio packet TNC.
//
// Copyright (C) 2013 John Langner, WB2OSZ
//
// 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.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
/*------------------------------------------------------------------
*
* Module: morse.c
*
* Purpose: Generate audio for morse code.
*
* Description:
*
* Reference:
*
*---------------------------------------------------------------*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <sys/time.h>
#if __WIN32__
#include <windows.h>
#else
#include <sys/termios.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#endif
#include "direwolf.h"
#include "textcolor.h"
#include "audio.h"
#include "ptt.h"
#define WPM 10
#define TIME_UNITS_TO_MS(tu,wpm) (((tu)*1200)/(wpm))
// TODO : should be in .h file.
/*
* Delay from PTT on to start of first character.
* Currently the only anticipated use for this is
* APRStt responses. In this case, we want an adequate
* delay for someone to press the # button, release
* the PTT button, and start listening for a response.
*/
#define MORSE_TXDELAY_MS 1500
/*
* Delay from end of last character to PTT off.
* Avoid chopping off the last element.
*/
#define MORSE_TXTAIL_MS 200
static const struct morse_s {
char ch;
char enc[7];
} morse[] = {
{ 'A', ".-" },
{ 'B', "-..." },
{ 'C', "-.-." },
{ 'D', "-.." },
{ 'E', "." },
{ 'F', "..-." },
{ 'G', "--." },
{ 'H', "...." },
{ 'I', "." },
{ 'J', ".---" },
{ 'K', "-.-" },
{ 'L', ".-.." },
{ 'M', "--" },
{ 'N', "-." },
{ 'O', "---" },
{ 'P', ".--." },
{ 'Q', "--.-" },
{ 'R', ".-." },
{ 'S', "..." },
{ 'T', "-" },
{ 'U', "..-" },
{ 'V', "...-" },
{ 'W', ".--" },
{ 'X', "-..-" },
{ 'Y', "-.--" },
{ 'Z', "--.." },
{ '1', ".----" },
{ '2', "..---" },
{ '3', "...--" },
{ '4', "....-" },
{ '5', "....." },
{ '6', "-...." },
{ '7', "--..." },
{ '8', "---.." },
{ '9', "----." },
{ '0', "-----" },
{ '-', "-...-" },
{ '.', ".-.-.-" },
{ ',', "--..--" },
{ '?', "..--.." },
{ '/', "-..-." }
};
#define NUM_MORSE (sizeof(morse) / sizeof(struct morse_s))
static void morse_tone (int tu);
static void morse_quiet (int tu);
static int morse_lookup (int ch);
static int morse_units_ch (int ch);
static int morse_units_str (char *str);
/*-------------------------------------------------------------------
*
* Name: morse_send
*
* Purpose: Given a string, generate appropriate lengths of
* tone and silence.
*
* Inputs: chan - Radio channel number.
* str - Character string to send.
* wpm - Speed in words per minute.
* txdelay - Delay (ms) from PTT to first character.
* txtail - Delay (ms) from last character to PTT off.
*
*
* Returns: Total number of milliseconds to activate PTT.
* This includes delays before the first character
* and after the last to avoid chopping off part of it.
*
* Description: xmit_thread calls this instead of the usual hdlc_send
* when we have a special packet that means send morse
* code.
*
*--------------------------------------------------------------------*/
int morse_send (int chan, char *str, int wpm, int txdelay, int txtail)
{
int time_units;
char *p;
time_units = 0;
for (p = str; *p != '\0'; p++) {
int i;
i = morse_lookup (*p);
if (i >= 0) {
const char *e;
for (e = morse[i].enc; *e != '\0'; e++) {
if (*e == '.') {
morse_tone (1);
time_units++;
}
else {
morse_tone (3);
time_units += 3;
}
if (e[1] != '\0') {
morse_quiet (1);
time_units++;
}
}
}
else {
morse_quiet (1);
time_units++;
}
if (p[1] != '\0') {
morse_quiet (3);
time_units += 3;
}
}
if (time_units != morse_units_str(str)) {
dw_printf ("morse: Internal error. Inconsistent length, %d vs. %d calculated.\n",
time_units, morse_units_str(str));
}
return (txdelay +
TIME_UNITS_TO_MS(time_units, wpm) +
txtail);
} /* end morse_send */
/*-------------------------------------------------------------------
*
* Name: morse_tone
*
* Purpose: Generate tone for specified number of time units.
*
* Inputs: tu - Number of time units.
*
*--------------------------------------------------------------------*/
static void morse_tone (int tu) {
int num_cycles;
int n;
for (n=0; n<tu; n++) {
dw_printf ("#");
}
} /* end morse_tone */
/*-------------------------------------------------------------------
*
* Name: morse_quiet
*
* Purpose: Generate silence for specified number of time units.
*
* Inputs: tu - Number of time units.
*
*--------------------------------------------------------------------*/
static void morse_quiet (int tu) {
int n;
for (n=0; n<tu; n++) {
dw_printf (".");
}
} /* end morse_quiet */
/*-------------------------------------------------------------------
*
* Name: morse_lookup
*
* Purpose: Given a character, find index in table above.
*
* Inputs: ch
*
* Returns: Index into table above or -1 if not found.
* Notice that space is not in the table.
* Any unusual character, that is not in the table,
* ends up being treated like space.
*
*--------------------------------------------------------------------*/
static int morse_lookup (int ch)
{
int i;
if (islower(ch)) {
ch = toupper(ch);
}
for (i=0; i<NUM_MORSE; i++) {
if (ch == morse[i].ch) {
return (i);
}
}
return (-1);
}
/*-------------------------------------------------------------------
*
* Name: morse_units_ch
*
* Purpose: Find number of time units for a character.
*
* Inputs: ch
*
* Returns: 1 for E (.)
* 3 for T (-)
* 3 for I.= (..)
* etc.
*
* The one unexpected result is 1 for space. Why not 7?
* When a space appears between two other characters,
* we already have 3 before and after so only 1 more is needed.
*
*--------------------------------------------------------------------*/
static int morse_units_ch (int ch)
{
int i;
int len;
int k;
int units;
i = morse_lookup (ch);
if (i < 0) {
return (1); /* space or any invalid character */
}
len = strlen(morse[i].enc);
units = len - 1;
for (k = 0; k < len; k++) {
switch (morse[i].enc[k]) {
case '.': units++; break;
case '-': units += 3; break;
default: dw_printf ("ERROR: morse_units_ch: should not be here.\n"); break;
}
}
return (units);
}
/*-------------------------------------------------------------------
*
* Name: morse_units_str
*
* Purpose: Find number of time units for a string of characters.
*
* Inputs: str
*
* Returns: 1 for E
* 5 for EE (1 + 3 + 1)
* 9 for E E (1 + 7 + 1)
* etc.
*
*--------------------------------------------------------------------*/
static int morse_units_str (char *str)
{
int i;
int len;
int k;
int units;
len = strlen(str);
units = (len - 1) * 3;
for (k = 0; k < len; k++) {
units += morse_units_ch(str[k]);
}
return (units);
}
int main (int argc, char *argv[]) {
dw_printf ("CQ DX\n");
morse_send (0, "CQ DX", 10, 10, 10);
dw_printf ("\n\n");
dw_printf ("wb2osz/9\n");
morse_send (0, "wb2osz/9", 10, 10, 10);
dw_printf ("\n\n");
}
/* end morse.c */