--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ad9912.c	Mon Mar 31 17:03:32 2014 +0200
@@ -0,0 +1,242 @@
+#ifdef _CVI_
+#include <ansi_c.h>
+#include <toolbox.h>
+#include <tcpsupp.h>
+#define TIMEOUT 0
+#define send(fd, buf, len, f)  ClientTCPWrite(fd, buf, len, TIMEOUT)
+#define recv(fd, buf, len, f)  ClientTCPRead(fd, buf, len, TIMEOUT)
+#define usleep(t)  Delay(t / 1000000.0)
+#define strdup(s)  StrDup(s)
+#else
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <ctype.h>
+#include <math.h>
+#include <stdarg.h>
+#endif
+
+#include "ad9912.h"
+
+#define streq(x, y) (strcmp((x), (y)) == 0)
+
+typedef unsigned long long uint64;
+
+
+static inline uint64 ftw(double clock, double freq)
+{
+	uint64 ftw = freq * ((double)(1 << 48) / clock);
+	ftw = ftw & ~1ULL;
+	return ftw;
+}
+
+
+static inline double freq(double clock, uint64 ftw)
+{
+	double freq = (double)ftw * (clock / (double)(1ULL << 48));
+	return freq;
+}
+
+
+static inline int strtouint64(const char *str, uint64 *v)
+{
+	char *end;
+	*v = strtoull(str, &end, 0);
+	if (*end != '\0')
+		return -1;
+	return 0;
+}
+
+
+static int msend(int fd, char *buffer, int n)
+{
+	int r;
+
+	buffer[n++] = '\r';
+	buffer[n++] = '\n';
+
+	r = send(fd, buffer, n, 0);
+	if (r < 0)
+		return r;     
+
+	return 0;
+}
+
+
+static int mrecv(int fd, char *buffer, int len)
+{
+	int n;
+
+	n = recv(fd, buffer, len, 0);
+	if (n < 0)
+		return n;
+
+	if ((buffer[--n] != '\n') || (buffer[--n] != '\r'))
+		return -1;
+
+	buffer[n] = '\0';
+
+	return n;
+}
+
+
+static int command(int fd, char *frmt, ...)
+{
+	int r, n;
+	char buffer[1024];
+	va_list v;
+
+	va_start(v, frmt);
+	n = vsnprintf(buffer, sizeof(buffer) - 2, frmt, v);
+	va_end(v);
+
+	r = msend(fd, buffer, n);
+	if (r < 0)
+		return r;
+
+	r = mrecv(fd, buffer, sizeof(buffer));
+	if (r < 0)
+		return r;
+
+	if (! streq(buffer, "OK"))
+		return -1;
+
+	return 0;
+}
+
+
+int ad9912_init(struct ad9912 *d, const char *hostname, double clock)
+{
+	int n, r;
+	char buffer[256];
+
+	d->hostname = StrDup(hostname);
+	d->port = 1234;
+	d->clock = clock;
+
+#ifdef _CVI_
+	unsigned int sock;
+	r = ConnectToTCPServer(&sock, d->port, d->hostname, NULL, NULL, TIMEOUT);
+	if (r < 0)
+		return -1;
+#else
+	int sock;
+	struct sockaddr_in addr;
+	struct hostent* host;	
+	
+	host = gethostbyname(hostname);
+	if (host == NULL)
+		return -1;
+  
+	sock = socket(AF_INET, SOCK_STREAM, 0);
+	if (sock < 0)
+		return -2;
+
+	addr.sin_family = host->h_addrtype;
+	memcpy(&addr.sin_addr.s_addr, host->h_addr_list[0], host->h_length);
+	addr.sin_port = htons(port);
+
+	r = connect(sock, (struct sockaddr*)&addr, sizeof(addr));
+	if (r < 0)
+		return -3;
+#endif
+
+	d->fd = sock;
+
+	/* check compatibility */
+	n = snprintf(buffer, sizeof(buffer), "REVISION");
+	r = msend(d->fd, buffer, n);
+	if (r < 0)
+		return r;
+	r = mrecv(d->fd, buffer, sizeof(buffer));
+	if (r < 0)
+		return r;
+	if (atoi(buffer) != REVISION)
+		return -1;
+
+	return 0;
+}
+
+
+int ad9912_set_frequency(struct ad9912 *d, unsigned channel, double f)
+{
+	int r;
+	uint64 value = ftw(d->clock, f);
+
+	r = command(d->fd, "SET CH%d:FTW0 0x%llX", channel, f);
+	if (r < 0)
+		return r;
+
+	d->frequency[channel] = freq(d->clock, value);
+     
+	return 0;
+}
+
+
+int ad9912_get_frequency(struct ad9912 *d, unsigned channel, double *f)
+{
+	int r, n;
+	uint64 value;
+	char buffer[256];
+
+	n = snprintf(buffer, sizeof(buffer), "GET CH%d:FTW0", channel);
+
+	r = msend(d->fd, buffer, n);
+	if (r < 0)
+		return r;
+
+	r = mrecv(d->fd, buffer, sizeof(buffer));
+	if (r < 0)
+		return r;
+
+	r = strtouint64(buffer, &value);
+	if (r < 0)
+		return r;
+
+	d->frequency[channel] = freq(d->clock, value);
+	if (f)
+		*f = d->frequency[channel];
+
+	return 0;
+}
+
+
+/**
+ * Ramp DDS frequency from @f1 to @f2 in steps @fstep with 0.01
+ * seconds delay after each step.
+ */
+int ad9912_ramp_frequency2(struct ad9912 *d, unsigned channel, double f1, double f2, double fstep)
+{
+	const int delay = 10000;
+	
+	/* f2 > f1 */
+	while ((f2 - f1) > fstep) {
+		f1 += fstep;
+		ad9912_set_frequency(d, channel, f1);
+		usleep(delay);
+	}
+	
+	/* f2 < f1 */
+	while ((f1 - f2) > fstep) {
+		f1 -= fstep;
+		ad9912_set_frequency(d, channel, f1);
+		usleep(delay);
+	}
+	
+	/* final adjustment */
+	ad9912_set_frequency(d, channel, f2);
+	return 0;
+}
+
+
+int ad9912_ramp_frequency(struct ad9912 *d, unsigned channel, double f, double fstep)
+{
+	return ad9912_ramp_frequency2(d, channel, d->frequency[channel], f, fstep);
+}