Merge branch 'iq' into interleaved_rg

1 files changed, 545 insertions, 0 deletions

diff --git a/src/fl2k_garage.c b/src/fl2k_garage.c
new file mode 100644
index 0000000..d50922e
--- /dev/null
+++ b/src/fl2k_garage.c
@@ -0,0 +1,545 @@
+/*
+ * osmo-fl2k, turns FL2000-based USB 3.0 to VGA adapters into
+ * low cost DACs
+ *
+ * Copyright (C) 2019 by Felix Erckenbrecht <eligs@eligs.de>
+ *
+ * based on fl2k_fm code by:
+ * Copyright (C) 2016-2018 by Steve Markgraf <steve@steve-m.de>
+ *
+ * based on FM modulator code from VGASIG:
+ * Copyright (C) 2009 by Bartek Kania <mbk@gnarf.org>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * 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/>.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <errno.h>
+#include <stdint.h>
+
+#ifndef _WIN32
+#include <unistd.h>
+#include <fcntl.h>
+#include <getopt.h>
+#else
+#include <windows.h>
+#include <io.h>
+#include <fcntl.h>
+#include "getopt/getopt.h"
+#endif
+
+#include <math.h>
+#include <pthread.h>
+
+#include "osmo-fl2k.h"
+#include "rds_mod.h"
+
+#define BUFFER_SAMPLES_SHIFT	16
+#define BUFFER_SAMPLES		(1 << BUFFER_SAMPLES_SHIFT)
+#define BUFFER_SAMPLES_MASK	((1 << BUFFER_SAMPLES_SHIFT)-1)
+
+#define AUDIO_BUF_SIZE		4096
+
+#define BASEBAND_SAMPLES_PER_CHIP 3
+#define BASEBAND_WORD_BITS 12
+#define BASEBAND_CHIPS_PER_BIT 3
+#define BASEBAND_CHIPS_PER_WORD (BASEBAND_WORD_BITS * BASEBAND_CHIPS_PER_BIT)
+#define BASEBAND_CHIPS_PER_SPACE BASEBAND_CHIPS_PER_WORD
+#define BASEBAND_SPACE_HIGH_CHIPS 1
+#define BASEBAND_SPACE_LOW_CHIPS (BASEBAND_CHIPS_PER_SPACE - BASEBAND_SPACE_HIGH_CHIPS)
+#define BASEBAND_CHIPS_TOTAL (BASEBAND_CHIPS_PER_SPACE + BASEBAND_CHIPS_PER_WORD)
+
+fl2k_dev_t *dev = NULL;
+int do_exit = 0;
+
+pthread_t am_thread;
+pthread_mutex_t cb_mutex;
+pthread_mutex_t am_mutex;
+pthread_cond_t cb_cond;
+pthread_cond_t am_cond;
+
+int16_t *sample_buf;
+int sample_buf_size;
+
+int8_t *txbuf = NULL;
+int8_t *ambuf = NULL;
+int8_t *buf1 = NULL;
+int8_t *buf2 = NULL;
+
+uint32_t samp_rate = 100000000;
+
+double mod_index = 0.9;
+int carrier_freq = 40685000;
+int carrier_per_signal;
+
+double *ampbuf;
+double *slopebuf;
+int writepos, readpos;
+
+void usage(void)
+{
+	fprintf(stderr,
+		"fl2k_garage, a garage door opener for FL2K VGA dongles\n\n"
+		"Usage:"
+		"\t[-d device index (default: 0)]\n"
+		"\t[-f carrier frequency (default: 40.685 MHz)]\n"
+		"\t[-c garage door code (12 Bit)]\n"
+		"\t[-b chip period in us (default 320 us)]\n"
+		"\t[-s samplerate in Hz (default: 100 MS/s)]\n"
+	);
+	exit(1);
+}
+
+#ifdef _WIN32
+BOOL WINAPI
+sighandler(int signum)
+{
+	if (CTRL_C_EVENT == signum) {
+		fprintf(stderr, "Signal caught, exiting!\n");
+		fl2k_stop_tx(dev);
+		do_exit = 1;
+		pthread_cond_signal(&am_cond);
+		return TRUE;
+	}
+	return FALSE;
+}
+#else
+static void sighandler(int signum)
+{
+	fprintf(stderr, "Signal caught, exiting!\n");
+	fl2k_stop_tx(dev);
+	do_exit = 1;
+	pthread_cond_signal(&am_cond);
+}
+#endif
+
+/* DDS Functions */
+
+#ifndef M_PI
+# define M_PI		3.14159265358979323846	/* pi */
+# define M_PI_2		1.57079632679489661923	/* pi/2 */
+# define M_PI_4		0.78539816339744830962	/* pi/4 */
+# define M_1_PI		0.31830988618379067154	/* 1/pi */
+# define M_2_PI		0.63661977236758134308	/* 2/pi */
+#endif
+#define DDS_2PI		(M_PI * 2)		/* 2 * Pi */
+#define DDS_3PI2	(M_PI_2 * 3)		/* 3/2 * pi */
+
+#define SIN_TABLE_ORDER	8
+#define SIN_TABLE_SHIFT	(32 - SIN_TABLE_ORDER)
+#define SIN_TABLE_LEN	(1 << SIN_TABLE_ORDER)
+#define ANG_INCR	(0xffffffff / DDS_2PI)
+
+int16_t sine_table[SIN_TABLE_LEN];
+int sine_table_init = 0;
+
+typedef struct {
+	double sample_freq;
+	double freq;
+	unsigned long int phase;
+	unsigned long int phase_step;
+	double amplitude;
+	double ampslope;
+} dds_t;
+
+static inline void dds_set_freq(dds_t *dds, double freq)
+{
+	dds->freq = freq;
+	dds->phase_step = (freq / dds->sample_freq) * 2 * M_PI * ANG_INCR;
+}
+
+static inline void dds_set_amp(dds_t *dds, double amplitude, double ampslope)
+{
+	dds->amplitude = amplitude;
+	dds->ampslope  = ampslope;
+}
+
+dds_t dds_init(double sample_freq, double freq, double phase, double amp)
+{
+	dds_t dds;
+	int i;
+
+	dds.sample_freq = sample_freq;
+	dds.phase = phase * ANG_INCR;
+	dds_set_freq(&dds, freq);
+	dds_set_amp(&dds, amp, 0);
+	/* Initialize sine table, prescaled for 16 bit signed integer */
+	if (!sine_table_init) {
+		double incr = 1.0 / (double)SIN_TABLE_LEN;
+		for (i = 0; i < SIN_TABLE_LEN; i++)
+			sine_table[i] = sin(incr * i * DDS_2PI) * 32767;
+
+		sine_table_init = 1;
+	}
+
+	return dds;
+}
+
+static inline int8_t dds_real(dds_t *dds)
+{
+	int tmp;
+	int32_t amp;
+
+	// advance dds generator
+	tmp = dds->phase >> SIN_TABLE_SHIFT;
+	dds->phase += dds->phase_step;
+	dds->phase &= 0xffffffff;
+
+	amp = (int32_t)(dds->amplitude * 255) * sine_table[tmp];
+	dds->amplitude += dds->ampslope;
+
+	return (int8_t)(amp >> 16) ;
+}
+
+static inline void dds_real_buf(dds_t *dds, int8_t *buf, int count)
+{
+	int i;
+	for (i = 0; i < count; i++)
+		buf[i] = dds_real(dds);
+}
+
+/* Signal generation and some helpers */
+
+/* Generate the radio signal using the pre-calculated amplitude information
+ * in the amp buffer */
+static void *am_worker(void *arg)
+{
+	register double freq;
+	register double tmp;
+	dds_t carrier;
+	int8_t *tmp_ptr;
+	uint32_t len = 0;
+	uint32_t readlen, remaining;
+	int buf_prefilled = 0;
+
+	/* Prepare the oscillators */
+	carrier = dds_init(samp_rate, carrier_freq, 1, 0);
+
+	while (!do_exit) {
+		dds_set_amp(&carrier, ampbuf[readpos], slopebuf[readpos]);
+		readpos++;
+		readpos &= BUFFER_SAMPLES_MASK;
+
+		/* check if we reach the end of the buffer */
+		if ((len + carrier_per_signal) > FL2K_BUF_LEN) {
+			readlen = FL2K_BUF_LEN - len;
+			remaining = carrier_per_signal - readlen;
+			dds_real_buf(&carrier, &ambuf[len], readlen);
+
+			if (buf_prefilled) {
+				/* swap buffers */
+				tmp_ptr = ambuf;
+				ambuf = txbuf;
+				txbuf = tmp_ptr;
+				pthread_cond_wait(&cb_cond, &cb_mutex);
+			}
+
+			dds_real_buf(&carrier, ambuf, remaining);
+			len = remaining;
+
+			buf_prefilled = 1;
+		} else {
+			dds_real_buf(&carrier, &ambuf[len], carrier_per_signal);
+			len += carrier_per_signal;
+		}
+
+		pthread_cond_signal(&am_cond);
+	}
+
+	pthread_exit(NULL);
+}
+
+static inline int writelen(int maxlen)
+{
+	int rp = readpos;
+	int len;
+	int r;
+
+	if (rp < writepos)
+		rp += BUFFER_SAMPLES;
+
+	len = rp - writepos;
+
+	r = len > maxlen ? maxlen : len;
+
+	return r;
+}
+
+static inline int32_t modulate_sample_am(int lastwritepos, double lastamp, int16_t sample)
+{
+	double amp, slope;
+
+	/* Calculate modulator amplitude at this point to lessen
+	 * the calculations needed in the signal generator */
+	amp = 1 - ((double)sample * mod_index);
+
+	/* What we do here is calculate a linear "slope" from
+	the previous sample to this one. This is then used by
+	the modulator to gently increase/decrease the amplitude
+	with each sample without the need to recalculate
+	the dds parameters. In fact this gives us a very
+	efficient and pretty good interpolation filter. */
+	slope = amp - lastamp;
+	slope /= carrier_per_signal;
+	slopebuf[lastwritepos] = slope;
+	ampbuf[writepos]       = amp;
+
+	return amp;
+}
+
+void am_modulator(const int code_input)
+{
+	int counter = 0;
+	int code;
+	unsigned int i;
+	unsigned int b = 0;
+	size_t len;
+	int32_t lastamp = 0;
+	uint32_t lastwritepos = writepos;
+	int16_t sample = 0;
+	int samplebuf_pos = 0;
+
+	/*
+	 *  3*640 us = 1,92 ms pro Symbol
+	 *  12 Symbole Daten (12 Bit)
+	 *  11 Symbole Pause, 1 Symbol 1 (synch)
+	 *
+	 *  1 = __-
+	 *  0 = _--
+	 */
+	while (!do_exit) {
+		len = writelen(AUDIO_BUF_SIZE);
+		if (len > 1) {
+			if (len == 0)
+				do_exit = 1;
+
+			for (i = 0; i < len; i++) {
+				/* Modulate and buffer the sample */
+				sample = sample_buf[samplebuf_pos++];
+				if(samplebuf_pos >= BASEBAND_SAMPLES_PER_CHIP * BASEBAND_CHIPS_TOTAL){
+					samplebuf_pos = 0;
+				}
+				lastamp = modulate_sample_am(lastwritepos, lastamp, sample);
+				lastwritepos = writepos++;
+				writepos %= BUFFER_SAMPLES;
+			}
+		} else {
+			pthread_cond_wait(&am_cond, &am_mutex);
+		}
+	}
+}
+
+void prepare_baseband(const int code_input, int16_t * sbuf){
+	int counter;
+	int b;
+	int sample_no;
+	int16_t sample;
+	int msb_first_code;
+
+	msb_first_code = 0;
+	// change to msb first and invert
+	for(b = 0;b<12;b++){
+		msb_first_code <<= 1;
+		msb_first_code |= code_input & (1<<b) ? 0 : 1;
+	}
+
+	sample_no = 0;
+	for(counter=0;counter < (BASEBAND_CHIPS_PER_SPACE + BASEBAND_CHIPS_PER_WORD) ; counter++){
+		for(b=0 ; b<BASEBAND_SAMPLES_PER_CHIP ; b++){
+			if(counter < (BASEBAND_SPACE_LOW_CHIPS)){
+				sample = 0;
+			}
+			else if(counter < (BASEBAND_CHIPS_PER_SPACE)){
+				// synch symbol
+				sample = 1;
+			}
+			else{
+				int m;
+				m = counter % BASEBAND_CHIPS_PER_BIT;
+				if(m == 0){
+					sample = 0;
+				}
+				else if(m == 1){
+					sample = (msb_first_code & 1);
+				}
+				else{
+					sample = 1;
+					if(b == BASEBAND_SAMPLES_PER_CHIP-1){
+						msb_first_code >>= 1;
+					}
+				}
+			}
+			sbuf[counter * BASEBAND_SAMPLES_PER_CHIP + b] = sample;
+		}
+	}
+}
+
+void fl2k_callback(fl2k_data_info_t *data_info)
+{
+	if (data_info->device_error) {
+		fprintf(stderr, "Device error, exiting.\n");
+		do_exit = 1;
+		pthread_cond_signal(&am_cond);
+	}
+
+	pthread_cond_signal(&cb_cond);
+
+	data_info->sampletype_signed = 1;
+	data_info->r_buf = (char *)txbuf;
+}
+
+int main(int argc, char **argv)
+{
+	int r, opt;
+	uint32_t buf_num = 0;
+	int dev_index = 0;
+	pthread_attr_t attr;
+	char *filename = NULL;
+	int option_index = 0;
+	int code = 0;
+	int chiptime_us = 320;
+
+#ifndef _WIN32
+	struct sigaction sigact, sigign;
+#endif
+
+	static struct option long_options[] =
+	{
+		{0, 0, 0, 0}
+	};
+
+	while (1) {
+		opt = getopt_long(argc, argv, "b:c:f:m:s:", long_options, &option_index);
+		/* end of options reached */
+		if (opt == -1)
+			break;
+
+		switch (opt) {
+		case 0:
+			break;
+		case 'b':
+			chiptime_us = atoi(optarg);
+			break;
+		case 'c':
+			code = atoi(optarg);
+			code &= 4095;
+			break;
+		case 'f':
+			carrier_freq = (uint32_t)atof(optarg);
+			break;
+		case 'm':
+			mod_index = atof(optarg);
+			break;
+		case 's':
+			samp_rate = (uint32_t)atof(optarg);
+			break;
+		default:
+			usage();
+			break;
+		}
+	}
+
+	if (argc < optind) {
+		usage();
+	}
+
+	/* allocate buffer */
+	buf1 = malloc(FL2K_BUF_LEN);
+	buf2 = malloc(FL2K_BUF_LEN);
+	if (!buf1 || !buf2) {
+		fprintf(stderr, "malloc error!\n");
+		exit(1);
+	}
+
+	ambuf = buf1;
+	txbuf = buf2;
+
+	/* Decoded audio */
+	slopebuf 	= malloc(BUFFER_SAMPLES * sizeof(double));
+	ampbuf  	= malloc(BUFFER_SAMPLES * sizeof(double));
+	slopebuf    = malloc(BUFFER_SAMPLES * sizeof(double));
+	sample_buf  = malloc((BASEBAND_SAMPLES_PER_CHIP * BASEBAND_CHIPS_TOTAL) * sizeof(int16_t));
+	readpos 	= 0;
+	writepos 	= 1;
+
+	fprintf(stderr, "Samplerate:\t%3.2f MHz\n", (double)samp_rate/1000000);
+	fprintf(stderr, "Carrier:\t%3.3f MHz\n", (double)carrier_freq/1000000);
+	fprintf(stderr, "Mod Index:\t%3.1f %%\n",
+					(double)(mod_index * 100));
+	fprintf(stderr, "Chip period:\t%d us\n", chiptime_us);
+
+	pthread_mutex_init(&cb_mutex, NULL);
+	pthread_mutex_init(&am_mutex, NULL);
+	pthread_cond_init(&cb_cond, NULL);
+	pthread_cond_init(&am_cond, NULL);
+	pthread_attr_init(&attr);
+
+	prepare_baseband(code, sample_buf);
+
+	fl2k_open(&dev, (uint32_t)dev_index);
+	if (NULL == dev) {
+		fprintf(stderr, "Failed to open fl2k device #%d.\n", dev_index);
+		goto out;
+	}
+
+	r = pthread_create(&am_thread, &attr, am_worker, NULL);
+	if (r < 0) {
+		fprintf(stderr, "Error spawning AM worker thread!\n");
+		goto out;
+	}
+
+	pthread_attr_destroy(&attr);
+	r = fl2k_start_tx(dev, fl2k_callback, NULL, 0);
+
+	/* Set the sample rate */
+	r = fl2k_set_sample_rate(dev, samp_rate);
+	if (r < 0)
+		fprintf(stderr, "WARNING: Failed to set sample rate. %d\n", r);
+
+	/* read back actual frequency */
+	samp_rate = fl2k_get_sample_rate(dev);
+
+	/* Calculate needed constants */
+	carrier_per_signal = (int)((double) samp_rate * chiptime_us/(1000000*BASEBAND_SAMPLES_PER_CHIP) + 0.5);
+	printf("Cps :\t%d\n", carrier_per_signal);
+#ifndef _WIN32
+	sigact.sa_handler = sighandler;
+	sigemptyset(&sigact.sa_mask);
+	sigact.sa_flags = 0;
+	sigign.sa_handler = SIG_IGN;
+	sigaction(SIGINT, &sigact, NULL);
+	sigaction(SIGTERM, &sigact, NULL);
+	sigaction(SIGQUIT, &sigact, NULL);
+	sigaction(SIGPIPE, &sigign, NULL);
+#else
+	SetConsoleCtrlHandler( (PHANDLER_ROUTINE) sighandler, TRUE );
+#endif
+
+	am_modulator(code);
+
+out:
+	fl2k_close(dev);
+
+	free(ampbuf);
+	free(slopebuf);
+	free(buf1);
+	free(buf2);
+
+	return 0;
+}