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Copyright (C) 4Front Technologies, 2002-2004. Released under GPLv2/CDDL.
This program is a significantly more complicated version of morse.c. It uses the select system call to be able to handle keyboard input and audio output at the same time. It shows how to prevent output underruns by writing silent samples to the audio device when there is no "payload" signal to play.
What the program does is playing randomly selected morse symbols (based on the command line options). At the same time it reads the keyboard and checks if the user typed the right character. This program doesn't stop to wait for the input. This simulates the real morse code exam but ufortunately this dosesn't work in practice.
Parts on this program are common with morse.c and commented only there.
The morse2.c program is a slightly different version of this one.
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <math.h>
#include <termios.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/types.h>
#include <soundcard.h>
#define BUFSZ (16*1024)
#define SRATE 48000
#define ATTACK 100
#define CHARDELAY 3
char randomlist[256];
int nrandom = 0;
int done = 0;
int charspeed, charsize;
int dotsize;
int audiofd = -1;
static int ncodes;
static int playc;
static int terminal_fd = 0;
static struct termios ti, saved_ti;
static int totalchars = 0;
static time_t t0;
double a, step;
#include "charlist.h"
int nplayed = 0, ntyped = 0;
char played_chars[4096], typed_chars[4096];
static void
check_results (void)
{
int i, j, n;
int errors = 0;
n = nplayed;
for (j = 0; j < n; j += 50)
{
printf ("Answer: ");
for (i = j; i < n && i < j + 50; i++)
{
if (i != j && !(i % 5))
printf (" ");
printf ("%c", typed_chars[i]);
}
printf ("\n");
printf ("Correct:");
for (i = j; i < n && i < j + 50; i++)
{
if (i != j && !(i % 5))
printf (" ");
if (typed_chars[i] != played_chars[i])
{
printf ("%c", played_chars[i]);
errors++;
}
else
printf (" ");
}
printf ("\n");
}
printf ("\n");
printf ("Errors: %d\n", errors);
}
static void
terminate (int sig)
{
time_t t;
t = time (0) - t0;
if (terminal_fd == -1)
return;
if (tcsetattr (terminal_fd, TCSAFLUSH, &saved_ti) == -1)
{
perror ("tcgetattr");
exit (-1);
}
printf ("\n\nTotal characters: %d\n", totalchars);
printf ("Elapsed time: %d seconds\n", t);
printf ("Characters per minute: %g\n",
t > 0?(float) totalchars / (float) t * 60.0:0);
printf ("\n");
check_results ();
exit (sig);
}
static int
genpulse (short *buf, int w, int state)
{
int i, l;
a = 0.0;
l = w * dotsize;
for (i = 0; i < ATTACK; i++)
{
double tmp = 0x7fff * cos (a * M_PI / 180.0);
tmp *= (double) (i) / (double) ATTACK;
*buf++ = (int) tmp *state;
a += step;
if (a > 360.0)
a -= 360.0;
}
for (i = ATTACK; i < l - ATTACK; i++)
{
double tmp = 0x7fff * cos (a * M_PI / 180.0);
*buf++ = (int) tmp *state;
a += step;
if (a > 360.0)
a -= 360.0;
}
for (i = l - ATTACK; i < l; i++)
{
double tmp = 0x7fff * cos (a * M_PI / 180.0);
tmp *= (double) (l - i) / (double) ATTACK;
*buf++ = (int) tmp *state;
a += step;
if (a > 360.0)
a -= 360.0;
}
return l;
}
static void
playerror (void)
{
short buffer[65536], *buf = buffer;
int i, l;
a = 0.0;
l = dotsize;
for (i = 0; i < ATTACK; i++)
{
double tmp = 0x7fff * cos (a * M_PI / 180.0);
tmp *= (double) (i) / (double) ATTACK;
*buf++ = (int) tmp;
a += step * 2.0;
if (a > 360.0)
a -= 360.0;
}
for (i = ATTACK; i < l - ATTACK; i++)
{
double tmp = 0x7fff * cos (a * M_PI / 180.0);
*buf++ = (int) tmp;
a += step * 2.0;
if (a > 360.0)
a -= 360.0;
}
for (i = l - ATTACK; i < l; i++)
{
double tmp = 0x7fff * cos (a * M_PI / 180.0);
tmp *= (double) (l - i) / (double) ATTACK;
*buf++ = (int) tmp;
a += step * 2.0;
if (a > 360.0)
a -= 360.0;
}
write (audiofd, buffer, 2 * l);
}
static int
genmorse (short *buf, char c)
{
int l = 0, i;
const char *s;
if (c == ' ')
return genpulse (buf, 4, 0);
for (i = 0; i < ncodes; i++)
if (Chars[i] == c)
{
s = Codes[i];
while (*s)
{
if (*s++ == '.')
l += genpulse (&buf[l], 1, 1);
else
l += genpulse (&buf[l], 3, 1);
l += genpulse (&buf[l], 1, 0);
}
l += genpulse (&buf[l], CHARDELAY, 0);
return l;
}
printf ("<?>");
fflush (stdout);
return 0;
}
static void
playchar (char c)
{
short buf[16 * BUFSZ];
int l;
l = 0;
if (c <= 'Z' && c >= 'A')
c += 32;
switch (c)
{
case ' ':
case '\n':
case '\t':
l = genmorse (buf, ' ');
break;
case '\r':
break;
case 'Å':
l = genmorse (buf, 'å');
break;
case 'Ä':
l = genmorse (buf, 'ä');
break;
case 'Ö':
l = genmorse (buf, 'ö');
break;
case 'Ü':
l = genmorse (buf, 'ü');
break;
default:
l = genmorse (buf, c);
}
write (audiofd, buf, 2 * l);
if (2 * l < charsize)
{
char tmp[512 * 1024];
l = charsize - 2 * l;
memset (tmp, 0, l);
write (audiofd, tmp, l);
}
}
static void
randomplay (void)
{
int old = playc;
if (totalchars == 100)
{
return;
}
// while (playc==old)
{
playc = random () % nrandom;
playc = randomlist[playc];
}
playchar (playc);
played_chars[nplayed++] = playc;
totalchars++;
}
static int
findcode (char c)
{
int i;
for (i = 0; i < ncodes; i++)
if (Chars[i] == c)
return i;
return 0;
}
static void
editor (char c)
{
int i;
if (c == 27) /* ESC */
terminate (SIGINT);
if (c == 8) /* BS */
{
if (ntyped > 0)
ntyped--;
return;
}
if (c == ' ') /* Sync */
{
for (i = ntyped; i < nplayed; i++)
typed_chars[i] = '_'; /* Empty placeholder */
ntyped = nplayed;
ioctl (audiofd, SNDCTL_DSP_HALT, 0);
return;
}
typed_chars[ntyped++] = c;
if (ntyped >= 100)
done = 1;
}
int
main (int argc, char *argv[])
{
char *devname = "/dev/dsp";
short buf[16 * BUFSZ];
char line[1024];
int i, parm;
int l, speed, wpm = 12;
fd_set readfds, writefds;
if (argc > 1)
devname = argv[1];
if (argc > 2)
{
wpm = atoi (argv[2]);
if (wpm == 0)
wpm = 12;
}
ncodes = strlen (Chars);
srandom (time (0));
if (argc > 3)
{
for (i = 3; i < argc; i++)
parse_charlist (argv[i]);
}
else
{
strcpy (randomlist, Chars);
nrandom = strlen (randomlist);
}
if (nrandom < 2)
{
printf ("Bad character list\n");
exit (-1);
}
randomlist[nrandom] = 0;
memset (typed_chars, ' ', sizeof (typed_chars));
printf ("Practicing codes: %s\n", randomlist);
for (i = 0; i <= nrandom; i += 4)
{
int j, k;
char line[256], tmp[20];
memset (line, ' ', 80), line[78] = 0;
for (j = 0; j < 4; j++)
if (i + j <= nrandom)
{
int ix;
ix = findcode (randomlist[i + j]);
sprintf (tmp, "%c %s", randomlist[i + j], Codes[ix]);
for (k = 0; k < strlen (tmp); k++)
line[j * 20 + k] = tmp[k];
}
printf ("%s\n", line);
}
speed = wpm;
printf ("Words per minute %d. Characters per minute %d\n", wpm, wpm * 5);
dotsize = SRATE / speed;
if ((audiofd = open (devname, O_WRONLY, 0)) == -1)
{
perror (devname);
exit (-1);
}
parm = 0x0004000a;
ioctl (audiofd, SNDCTL_DSP_SETFRAGMENT, &parm);
parm = AFMT_S16_LE;
if (ioctl (audiofd, SNDCTL_DSP_SETFMT, &parm) == -1)
{
perror ("SETFMT");
close (audiofd);
exit (-1);
}
if (parm != AFMT_S16_LE)
{
printf
("Error: 32/24 bit sample format is not supported by the device\n");
printf ("%08x/%08x\n", parm, AFMT_S16_LE);
close (audiofd);
exit (-1);
}
parm = SRATE;
if (ioctl (audiofd, SNDCTL_DSP_SPEED, &parm) == -1)
{
perror ("SPEED");
close (audiofd);
exit (-1);
}
if (parm != SRATE)
{
printf
("Error: %d Hz sampling rate is not supported by the device (%d)\n",
SRATE, parm);
close (audiofd);
exit (-1);
}
if (tcgetattr (terminal_fd, &saved_ti) == -1)
{
perror ("tcgetattr");
exit (-1);
}
signal (SIGINT, terminate);
Line setup
if (tcgetattr (terminal_fd, &ti) == -1)
{
perror ("tcgetattr");
exit (-1);
}
ti.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
ti.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
ti.c_cflag &= ~(CSIZE | PARENB);
ti.c_cflag |= CS8;
ti.c_oflag &= ~(OPOST);
ti.c_cc[VMIN] = 1;
ti.c_cc[VTIME] = 1;
if (tcsetattr (terminal_fd, TCSAFLUSH, &ti) == -1)
{
perror ("tcgetattr");
exit (-1);
}
a = 0.0;
step = 360.0 * 600.0 / parm;
l = 0;
l += genpulse (&buf[l], 1, 0);
write (audiofd, buf, l * 2);
memset (buf, 0, 4096);
for (i = 0; i < 2; i++)
write (audiofd, buf, 4096);
charspeed = speed * 5;
if (charspeed > 25)
charspeed = 25;
charsize = 60 * SRATE * 2 / charspeed;
printf ("Charrate %d chars/min -> (%d samples)\n", charspeed, charsize);
printf ("\r\n");
randomplay ();
t0 = time (0);
while (!done)
{
int n;
FD_ZERO (&readfds);
FD_ZERO (&writefds);
FD_SET (audiofd, &writefds);
FD_SET (0, &readfds);
if ((n = select (audiofd + 1, &readfds, &writefds, NULL, NULL)) == -1)
{
perror ("select");
exit (-1);
}
if (n == 0)
continue;
if (FD_ISSET (0, &readfds))
{
if (read (0, line, 1) == 1)
editor (*line);
}
if (FD_ISSET (audiofd, &writefds))
{
if (!(nplayed % 5))
playchar (' ');
randomplay ();
}
}
terminate (15);
close (audiofd);
exit (0);
}