working sync and audio

9 files changed, 186 insertions, 26 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..1c47c50
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,9 @@
+*.o
+*.d
+core
+*.orig
+*.swp
+*.swo
+*%
+*~
+msf
diff --git a/Makefile b/Makefile
index 01a4471..edd9837 100644
--- a/Makefile
+++ b/Makefile
@@ -1,11 +1,18 @@
-CSRCS=time_fn.c msf.c util.c main.c
+CSRCS=time_fn.c msf.c util.c main.c signal.c sync.c audio.c
 HSRCS=time_fn.h project.h
+PROG=msf
+AO_CFLAGS=$(shell pkg-config --cflags ao)
+AO_LIBS=$(shell pkg-config --libs ao)
+LIBS=-lm $(AO_LIBS)
+CPPFLAGS=$(AO_CFLAGS)
+
+
+
+#####################
 
 OBJS=${CSRCS:%.c=%.o}
 
-PROG=msf
 
-CPPFLAGS=
 CFLAGS=-Wall ${CPPFLAGS}
 
 CPROTO=cproto
diff --git a/audio.c b/audio.c
new file mode 100644
index 0000000..83e6de9
--- /dev/null
+++ b/audio.c
@@ -0,0 +1,33 @@
+#include "project.h"
+#include <ao/ao.h>
+
+static ao_device  *device;
+static int d_num;
+
+void audio_init (void)
+{
+
+  ao_initialize();
+
+  d_num = ao_default_driver_id();
+}
+
+void audio_start (void)
+{
+  ao_sample_format fmt = {0};
+
+
+  fmt.bits = 16;
+  fmt.rate = SAMPLE_RATE;
+  fmt.channels = 1;
+  fmt.byte_format = AO_FMT_NATIVE;
+  fmt.matrix = 0;
+
+  device = ao_open_live (d_num, &fmt, NULL);
+}
+
+
+void audio_play (void *data, size_t len)
+{
+  ao_play (device, data, len);
+}
diff --git a/main.c b/main.c
index 5eae5ea..5b18a72 100644
--- a/main.c
+++ b/main.c
@@ -2,6 +2,7 @@
 
 
 
+
 int main (int argc, char *argv[])
 {
   EPOCH e;
@@ -11,35 +12,38 @@ int main (int argc, char *argv[])
 
   unsigned i;
 
+  signal_init();
+
+  audio_init();
 
-  gettimeofday (&tv, NULL);
+  audio_start();
+  sync_to_minute (&tv);
 
   e.s = tv.tv_sec;
   e.ns = tv.tv_usec * 1000;
 
-  u = time_epoch_to_utc (e);
 
+  for (;;) {
+    e.s += 60;
+    u = time_epoch_to_utc (e);
+    time_print_utc ("Next:\n", u);
+    msf_make_stream (s, u);
 
-  time_print_utc ("Now:\n", u);
 
-  {
-    uint8_t a[60], b[60];
-    msf_make_bits (u, a, b);
+    for (i = 0; i < 600; ++i) {
+      signal_send_bp (s[i]);
 
-    msf_make_stream (s, a, b);
-  }
+      putchar ('0' + s[i]);
+      fflush (stdout);
 
+      if ((i % 10) == 9) putchar (' ');
 
-  for (i = 0; i < 600; ++i) {
-    putchar ('0' + s[i]);
+      if ((i % 50) == 49) putchar ('\n');
+    }
 
-    if ((i % 10) == 9) putchar (' ');
+    printf ("\n");
   }
 
-  printf ("\n");
-
-
-
   return 0;
 
 }
diff --git a/msf.c b/msf.c
index 47e5188..411b601 100644
--- a/msf.c
+++ b/msf.c
@@ -19,7 +19,7 @@ static void msf_set_ident (uint8_t *i)
 
 
 
-void msf_make_bits (UTC u, uint8_t *a, uint8_t *b)
+static void msf_make_bits (UTC u, uint8_t *a, uint8_t *b)
 {
 
   bzero (a, 60);
@@ -53,20 +53,25 @@ void msf_make_bits (UTC u, uint8_t *a, uint8_t *b)
 
 
 
-void msf_make_stream (uint8_t *v, uint8_t *a, uint8_t *b)
+void msf_make_stream (uint8_t *v, UTC u)
 {
   unsigned s;
+  uint8_t a[60], b[60];
+  uint8_t *pa, *pb;
+
+  msf_make_bits (u, a, b);
+
   bzero (v, 600);
 
-  for (s = 0; s < 60; ++s, v += 10, ++a, ++b) {
+  for (s = 0, pa = a, pb = b; s < 60; ++s, v += 10, ++pa, ++pb) {
 
     if (!s)
       memset (v, 1, 5);
 
-
     v[0] = 1;
-    v[1] = *a;
-    v[2] = *b;
+    v[1] = *pa;
+    v[2] = *pb;
   }
 }
 
+
diff --git a/project.h b/project.h
index 9492bac..f6ad552 100644
--- a/project.h
+++ b/project.h
@@ -6,7 +6,12 @@
 #include <sys/time.h>
 #include <string.h>
 #include <strings.h>
+#include <unistd.h>
+#include <math.h>
 
+#define KHZ(a) ((a)*1000)
+#define SAMPLE_RATE KHZ(48)
+#define CARRIER KHZ(20)
 
 #include "time_fn.h"
 
diff --git a/prototypes.h b/prototypes.h
index fc09337..e6c95a4 100644
--- a/prototypes.h
+++ b/prototypes.h
@@ -5,10 +5,19 @@ extern void utc_to_str(char *dst, UTC u);
 extern void time_print_utc(const char *p, UTC u);
 extern void time_print_epoch(const char *p, EPOCH e);
 /* msf.c */
-extern void msf_make_bits(UTC u, uint8_t *a, uint8_t *b);
-extern void msf_make_stream(uint8_t *v, uint8_t *a, uint8_t *b);
+extern void msf_make_stream(uint8_t *v, UTC u);
 /* util.c */
 extern int set_parity(uint8_t *d, unsigned s, unsigned e);
 extern void bcd_set(uint8_t *d, unsigned s, unsigned e, unsigned v);
 /* main.c */
 extern int main(int argc, char *argv[]);
+/* signal.c */
+extern void signal_init(void);
+extern void signal_send_bp(int b);
+/* sync.c */
+extern void sync_to_second(struct timeval *ret);
+extern void sync_to_minute(struct timeval *ret);
+/* audio.c */
+extern void audio_init(void);
+extern void audio_start(void);
+extern void audio_play(void *data, size_t len);
diff --git a/signal.c b/signal.c
new file mode 100644
index 0000000..3e7319d
--- /dev/null
+++ b/signal.c
@@ -0,0 +1,34 @@
+#include "project.h"
+
+
+#define SPP (SAMPLE_RATE/10)
+
+static int16_t zero[SPP];
+static int16_t one[SPP];
+
+
+void signal_init (void)
+{
+  unsigned i;
+  double t;
+
+  bzero (one, sizeof (one));
+
+  for (i = 0; i < SPP; ++i) {
+
+    t = (1.0 / (double) SAMPLE_RATE) * (double) i;
+    t *= CARRIER * 2.0 * M_PI;
+
+    zero[i] = 32000 * sin (t);
+  }
+
+}
+
+void signal_send_bp (int b)
+{
+  if (b)
+    audio_play (one, sizeof (one));
+  else
+    audio_play (zero, sizeof (zero));
+}
+
diff --git a/sync.c b/sync.c
new file mode 100644
index 0000000..1b6b6bc
--- /dev/null
+++ b/sync.c
@@ -0,0 +1,54 @@
+#include "project.h"
+
+#define SLEEP_MIN 100000
+#define THRESH 1000
+
+void sync_to_second (struct timeval *ret)
+{
+  struct timeval tv1, tv2;
+  ret->tv_usec = 0;
+
+  for (;;) {
+    tv2.tv_sec = 0;
+    gettimeofday (&tv1, NULL);
+    tv2.tv_usec = 1000000 - tv1.tv_usec;
+
+    if (tv1.tv_usec < THRESH) {
+      ret->tv_sec = tv1.tv_sec;
+      return;
+    } else if (tv2.tv_usec < THRESH) {
+      ret->tv_sec = tv1.tv_sec + 1;
+      return;
+    }
+
+    if (tv2.tv_usec > SLEEP_MIN)
+      select (0, NULL, NULL, NULL, &tv2);
+    else
+      usleep (tv2.tv_usec / 2);
+  }
+}
+
+
+
+void sync_to_minute (struct timeval *ret)
+{
+  struct timeval tv1, tv2;
+  ret->tv_usec = 0;
+
+  for (;;) {
+    tv2.tv_sec = 0;
+    gettimeofday (&tv1, NULL);
+    tv2.tv_sec = 60 - (tv1.tv_sec % 60);
+    tv2.tv_usec = 1000;
+
+    printf ("%d seconds left in min\n", (int) tv2.tv_sec);
+
+    if (tv2.tv_sec > 1) {
+      tv2.tv_sec /= 2;
+      select (0, NULL, NULL, NULL, &tv2);
+    } else {
+      sync_to_second (ret);
+      return;
+    }
+  }
+}