static void send_packet (char *str)
{
packet_t pp;
unsigned char fbuf[AX25_MAX_PACKET_LEN+2];
int flen;
int c;
pp = ax25_from_text (str, 1);
flen = ax25_pack (pp, fbuf);
for (c=0; c<modem.adev[0].num_channels; c++)
{
hdlc_send_flags (c, 8, 0);
hdlc_send_frame (c, fbuf, flen);
hdlc_send_flags (c, 2, 1);
}
ax25_delete (pp);
}
static void xmit_ax25_frames (int c, int p, packet_t pp)
{
unsigned char fbuf[AX25_MAX_PACKET_LEN+2];
int flen;
char stemp[1024]; /* max size needed? */
int info_len;
unsigned char *pinfo;
int pre_flags, post_flags;
int num_bits; /* Total number of bits in transmission */
/* including all flags and bit stuffing. */
int duration; /* Transmission time in milliseconds. */
int already;
int wait_more;
int maxframe; /* Maximum number of frames for one transmission. */
int numframe; /* Number of frames sent during this transmission. */
/*
* These are for timing of a transmission.
* All are in usual unix time (seconds since 1/1/1970) but higher resolution
*/
double time_ptt; /* Time when PTT is turned on. */
double time_now; /* Current time. */
int nb;
maxframe = (p == TQ_PRIO_0_HI) ? 1 : 7;
/*
* Print trasmitted packet. Prefix by channel and priority.
* Do this before we get into the time critical part.
*/
ax25_format_addrs (pp, stemp);
info_len = ax25_get_info (pp, &pinfo);
text_color_set(DW_COLOR_XMIT);
dw_printf ("[%d%c] ", c, p==TQ_PRIO_0_HI ? 'H' : 'L');
dw_printf ("%s", stemp); /* stations followed by : */
ax25_safe_print ((char *)pinfo, info_len, ! ax25_is_aprs(pp));
dw_printf ("\n");
(void)ax25_check_addresses (pp);
/* Optional hex dump of packet. */
if (g_debug_xmit_packet) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("------\n");
ax25_hex_dump (pp);
dw_printf ("------\n");
}
/*
* Turn on transmitter.
* Start sending leading flag bytes.
*/
time_ptt = dtime_now ();
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("xmit_thread: Turn on PTT now for channel %d. speed = %d\n", c, xmit_bits_per_sec[c]);
#endif
ptt_set (OCTYPE_PTT, c, 1);
pre_flags = MS_TO_BITS(xmit_txdelay[c] * 10, c) / 8;
num_bits = hdlc_send_flags (c, pre_flags, 0);
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("xmit_thread: txdelay=%d [*10], pre_flags=%d, num_bits=%d\n", xmit_txdelay[c], pre_flags, num_bits);
#endif
/*
* Transmit the frame.
*/
flen = ax25_pack (pp, fbuf);
assert (flen >= 1 && flen <= sizeof(fbuf));
nb = hdlc_send_frame (c, fbuf, flen);
num_bits += nb;
numframe = 1;
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("xmit_thread: flen=%d, nb=%d, num_bits=%d, numframe=%d\n", flen, nb, num_bits, numframe);
#endif
ax25_delete (pp);
/*
* Additional packets if available and not exceeding max.
*/
while (numframe < maxframe && tq_count (c,p) > 0) {
pp = tq_remove (c, p);
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("xmit_thread: tq_remove(chan=%d, prio=%d) returned %p\n", c, p, pp);
#endif
ax25_format_addrs (pp, stemp);
info_len = ax25_get_info (pp, &pinfo);
text_color_set(DW_COLOR_XMIT);
dw_printf ("[%d%c] ", c, p==TQ_PRIO_0_HI ? 'H' : 'L');
dw_printf ("%s", stemp); /* stations followed by : */
ax25_safe_print ((char *)pinfo, info_len, ! ax25_is_aprs(pp));
dw_printf ("\n");
(void)ax25_check_addresses (pp);
if (g_debug_xmit_packet) {
text_color_set(DW_COLOR_DEBUG);
dw_printf ("------\n");
ax25_hex_dump (pp);
dw_printf ("------\n");
}
/*
* Transmit the frame.
*/
flen = ax25_pack (pp, fbuf);
assert (flen >= 1 && flen <= sizeof(fbuf));
nb = hdlc_send_frame (c, fbuf, flen);
num_bits += nb;
numframe++;
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("xmit_thread: flen=%d, nb=%d, num_bits=%d, numframe=%d\n", flen, nb, num_bits, numframe);
#endif
ax25_delete (pp);
}
/*
* Need TXTAIL because we don't know exactly when the sound is done.
*/
post_flags = MS_TO_BITS(xmit_txtail[c] * 10, c) / 8;
nb = hdlc_send_flags (c, post_flags, 1);
num_bits += nb;
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("xmit_thread: txtail=%d [*10], post_flags=%d, nb=%d, num_bits=%d\n", xmit_txtail[c], post_flags, nb, num_bits);
#endif
/*
* While demodulating is CPU intensive, generating the tones is not.
* Example: on the RPi, with 50% of the CPU taken with two receive
* channels, a transmission of more than a second is generated in
* about 40 mS of elapsed real time.
*/
audio_wait(ACHAN2ADEV(c));
/*
* Ideally we should be here just about the time when the audio is ending.
* However, the innards of "audio_wait" are not satisfactory in all cases.
*
* Calculate how long the frame(s) should take in milliseconds.
*/
duration = BITS_TO_MS(num_bits, c);
/*
* See how long it has been since PTT was turned on.
* Wait additional time if necessary.
*/
time_now = dtime_now();
already = (int) ((time_now - time_ptt) * 1000.);
wait_more = duration - already;
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
dw_printf ("xmit_thread: xmit duration=%d, %d already elapsed since PTT, wait %d more\n", duration, already, wait_more );
#endif
if (wait_more > 0) {
SLEEP_MS(wait_more);
}
else if (wait_more < -100) {
/* If we run over by 10 mSec or so, it's nothing to worry about. */
/* However, if PTT is still on about 1/10 sec after audio */
/* should be done, something is wrong. */
/* Looks like a bug with the RPi audio system. Never an issue with Ubuntu. */
/* This runs over randomly sometimes. TODO: investigate more fully sometime. */
#ifndef __arm__
text_color_set(DW_COLOR_ERROR);
dw_printf ("Transmit timing error: PTT is on %d mSec too long.\n", -wait_more);
#endif
}
/*
* Turn off transmitter.
*/
#if DEBUG
text_color_set(DW_COLOR_DEBUG);
time_now = dtime_now();
dw_printf ("xmit_thread: Turn off PTT now. Actual time on was %d mS, vs. %d desired\n", (int) ((time_now - time_ptt) * 1000.), duration);
#endif
ptt_set (OCTYPE_PTT, c, 0);
} /* end xmit_ax25_frames */
