SDR: Display IQ data as a plot using 'q' key

src/common/Makefile.am

@@ -24,6 +24,7 @@ libcommon_a_SOURCES = \
 	../common/compandor.c \
 	../common/sender.c \
 	../common/display_wave.c \
+	../common/display_iq.c \
 	../common/main_common.c
 
 if HAVE_SDR

src/common/debug.c

@@ -24,7 +24,7 @@
 #include <stdint.h>
 #include <errno.h>
 #include "debug.h"
-#include "display_wave.h"
+#include "display.h"
 #include "call.h"
 
 const char *debug_level[] = {
@@ -94,9 +94,11 @@ void _printdebug(const char *file, const char __attribute__((unused)) *function,
 
 	clear_console_text();
 //	printf("%s%s:%d %s() %s: %s\033[0;39m", debug_cat[cat].color, file, line, function, debug_level[level], buffer);
-	display_limit_scroll(1);
+	display_wave_limit_scroll(1);
+	display_iq_limit_scroll(1);
 	printf("%s%s:%d %s: %s\033[0;39m", debug_cat[cat].color, file, line, debug_level[level], buffer);
-	display_limit_scroll(0);
+	display_wave_limit_scroll(0);
+	display_iq_limit_scroll(0);
 	print_console_text();
 	fflush(stdout);
 }

src/common/display.h

@@ -0,0 +1,32 @@
+#define MAX_DISPLAY_WIDTH 1024
+
+typedef struct sender sender_t;
+
+typedef struct display_wave {
+	int	interval_pos;
+	int	interval_max;
+	int	offset;
+	int16_t buffer[MAX_DISPLAY_WIDTH];
+} dispwav_t;
+
+#define MAX_DISPLAY_IQ 256
+
+typedef struct display_iq {
+	int	interval_pos;
+	int	interval_max;
+	int	offset;
+	float buffer[MAX_DISPLAY_IQ * 2];
+} dispiq_t;
+
+void get_win_size(int *w, int *h);
+
+void display_wave_init(sender_t *sender, int samplerate);
+void display_wave_on(int on);
+void display_wave_limit_scroll(int on);
+void display_wave(sender_t *sender, int16_t *samples, int length);
+
+void display_iq_init(int samplerate);
+void display_iq_on(int on);
+void display_iq_limit_scroll(int on);
+void display_iq(float *samples, int length);
+

src/common/display_iq.c

@@ -0,0 +1,231 @@
+/* display IQ data form functions
+ *
+ * (C) 2016 by Andreas Eversberg <jolly@eversberg.eu>
+ * All Rights Reserved
+ *
+ * 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 3 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 <stdint.h>
+#include <string.h>
+#include <math.h>
+#include "sender.h"
+
+#define DISPLAY_INTERVAL 0.04
+
+/* must be odd value! */
+#define SIZE	23
+
+static char screen[SIZE][MAX_DISPLAY_WIDTH];
+static int iq_on = 0;
+static double db = 80;
+
+static dispiq_t disp;
+
+void display_iq_init(int samplerate)
+{
+	memset(&disp, 0, sizeof(disp));
+	disp.interval_max = (double)samplerate * DISPLAY_INTERVAL + 0.5;
+	/* should not happen due to low interval */
+	if (disp.interval_max < MAX_DISPLAY_IQ + 1)
+		disp.interval_max = MAX_DISPLAY_IQ + 1;
+}
+
+void display_iq_on(int on)
+{
+	int j;
+	int w, h;
+
+	get_win_size(&w, &h);
+
+	if (iq_on) {
+		memset(&screen, ' ', sizeof(screen));
+		printf("\0337\033[H");
+		for (j = 0; j < SIZE; j++) {
+			screen[j][w] = '\0';
+			puts(screen[j]);
+		}
+		printf("\0338"); fflush(stdout);
+	}
+
+	if (on < 0) {
+		if (++iq_on == 3)
+			iq_on = 0;
+	} else
+		iq_on = on;
+}
+
+void display_iq_limit_scroll(int on)
+{
+	int w, h;
+
+	if (!iq_on)
+		return;
+
+	get_win_size(&w, &h);
+
+	printf("\0337");
+	printf("\033[%d;%dr", (on) ? SIZE + 1 : 1, h);
+	printf("\0338");
+}
+
+/*
+ * plot IQ data:
+ *
+ * theoretical example: SIZE = 3 allows 6 steps plotted as dots
+ *
+ * Line 0:   :
+ * Line 1:   :
+ * Line 2:   :
+ *
+ * The level of -1.0 .. 1.0 is scaled to -3 and 3.
+ *
+ * The lowest of the upper 3 dots ranges from 0.0 .. <1.5.
+ * The upper most dot ranges from 2.5 .. <3.5.
+ * The highest of the lower 3 dots ranges from <0.0 .. >-1.5;
+ * The lower most dot ranges from -2.5 .. >-3.5.
+ *
+ * The center column ranges from -0.5 .. <0.5.
+ * The columns about the center from -1.5 .. <1.5.
+ */
+void display_iq(float *samples, int length)
+{
+	int pos, max;
+	float *buffer;
+	int i, j, k;
+	int color = 9; /* default color */
+	int x_center, y_center;
+	double I, Q, l, s;
+	int x, y;
+	int width, h;
+
+	if (!iq_on)
+		return;
+
+	get_win_size(&width, &h);
+
+	/* at what line we draw our zero-line and what character we use */
+	x_center = width >> 1;
+	y_center = (SIZE - 1) >> 1;
+
+	pos = disp.interval_pos;
+	max = disp.interval_max;
+	buffer = disp.buffer;
+
+	for (i = 0; i < length; i++) {
+		if (pos >= MAX_DISPLAY_IQ) {
+			if (++pos == max)
+				pos = 0;
+			continue;
+		}
+		buffer[pos++] = *samples++;
+		buffer[pos++] = *samples++;
+		if (pos == MAX_DISPLAY_IQ) {
+			memset(&screen, ' ', sizeof(screen));
+			for (j = 0; j < MAX_DISPLAY_IQ; j++) {
+				I = buffer[j * 2];
+				Q = buffer[j * 2 + 1];
+				if (iq_on > 1) {
+					/* logarithmic scale */
+					l = sqrt(I*I + Q*Q);
+					s = log10(l) * 20 + db;
+					if (s < 0)
+						s = 0;
+					I = (I / l) * (s / db);
+					Q = (Q / l) * (s / db);
+				}
+				x = x_center + (int)(I * (double)SIZE + (double)width + 0.5) - width;
+				if (x < 0)
+					continue;
+				if (x > width - 1)
+					continue;
+				if (Q >= 0)
+					y = SIZE - 1 - (int)(Q * (double)SIZE - 0.5);
+				else
+					y = SIZE - (int)(Q * (double)SIZE + 0.5);
+				if (y < 0)
+					continue;
+				if (y > SIZE * 2 - 1)
+					continue;
+				if (screen[y/2][x] == ':')
+					continue;
+				if (screen[y/2][x] == '.') {
+					if ((y & 1) == 0)
+						screen[y/2][x] = ':';
+					continue;
+				}
+				if (screen[y/2][x] == '\'') {
+					if ((y & 1))
+						screen[y/2][x] = ':';
+					continue;
+				}
+				if ((y & 1) == 0)
+					screen[y/2][x] = '\'';
+				else
+					screen[y/2][x] = '.';
+			}
+			if (iq_on == 1)
+				sprintf(screen[0], "(IQ linear");
+			else
+				sprintf(screen[0], "(IQ log %.0f dB", db);
+			*strchr(screen[0], '\0') = ')';
+			printf("\0337\033[H");
+			for (j = 0; j < SIZE; j++) {
+				for (k = 0; k < width; k++) {
+					if ((j == y_center || k == x_center) && screen[j][k] == ' ') {
+						/* blue cross */
+						if (color != 4) {
+							color = 4;
+							printf("\033[0;34m");
+						}
+						if (j == y_center) {
+							if (k == x_center)
+								putchar('o');
+							else if (k == x_center - SIZE)
+								putchar('+');
+							else if (k == x_center + SIZE)
+								putchar('+');
+							else
+								putchar('-');
+						} else
+							putchar('|');
+					} else if (screen[j][k] == ':' || screen[j][k] == '.' || screen[j][k] == '\'') {
+						/* green plot */
+						if (color != 2) {
+							color = 2;
+							printf("\033[1;32m");
+						}
+						putchar(screen[j][k]);
+					} else if (screen[j][k] != ' ') {
+						/* white other characters */
+						if (color != 7) {
+							color = 7;
+							printf("\033[1;37m");
+						}
+						putchar(screen[j][k]);
+					} else
+						putchar(screen[j][k]);
+				}
+				printf("\n");
+			}
+			/* reset color and position */
+			printf("\033[0;39m\0338"); fflush(stdout);
+		}
+	}
+
+	disp.interval_pos = pos;
+}
+
+

src/common/display_wave.c

@@ -31,7 +31,7 @@ static int num_sender = 0;
 static char screen[HEIGHT][MAX_DISPLAY_WIDTH];
 static int wave_on = 0;
 
-static void get_win_size(int *w, int *h)
+void get_win_size(int *w, int *h)
 {
 	struct winsize win;
 	int rc;
@@ -65,23 +65,25 @@ void display_wave_on(int on)
 
 	get_win_size(&w, &h);
 
+	if (wave_on) {
+		memset(&screen, ' ', sizeof(screen));
+		printf("\0337\033[H");
+		for (i = 0; i < num_sender; i++) {
+			for (j = 0; j < HEIGHT; j++) {
+				screen[j][w] = '\0';
+				puts(screen[j]);
+			}
+		}
+		printf("\0338"); fflush(stdout);
+	}
+
 	if (on < 0)
 		wave_on = 1 - wave_on;
 	else
 		wave_on = on;
-
-	memset(&screen, ' ', sizeof(screen));
-	printf("\0337\033[H");
-	for (i = 0; i < num_sender; i++) {
-		for (j = 0; j < HEIGHT; j++) {
-			screen[j][w] = '\0';
-			puts(screen[j]);
-		}
-	}
-	printf("\0338"); fflush(stdout);
 }
 
-void display_limit_scroll(int on)
+void display_wave_limit_scroll(int on)
 {
 	int w, h;
 

src/common/display_wave.h

@@ -1,16 +0,0 @@
-#define MAX_DISPLAY_WIDTH 1024
-
-typedef struct sender sender_t;
-
-typedef struct display_wave {
-	int	interval_pos;
-	int	interval_max;
-	int	offset;
-	int16_t buffer[MAX_DISPLAY_WIDTH];
-} dispwav_t;
-
-void display_wave_init(sender_t *sender, int samplerate);
-void display_wave_on(int on);
-void display_limit_scroll(int on);
-void display_wave(sender_t *sender, int16_t *samples, int length);
-

src/common/main_common.c

@@ -431,8 +431,14 @@ next_char:
 			goto next_char;
 		case 'w':
 			/* toggle display */
+			display_iq_on(0);
 			display_wave_on(-1);
 			goto next_char;
+		case 'q':
+			/* toggle display */
+			display_wave_on(0);
+			display_iq_on(-1);
+			goto next_char;
 		case 'i':
 			/* dump info */
 			dump_info();

src/common/sdr.c

@@ -83,6 +83,8 @@ void *sdr_open(const char __attribute__((__unused__)) *audiodev, double *tx_freq
 	int rc;
 	int c;
 
+	display_iq_init(samplerate);
+
 	if (channels < 1) {
 		PDEBUG(DSDR, DEBUG_ERROR, "No channel given, please fix!\n");
 		abort();
@@ -283,6 +285,8 @@ int sdr_read(void *inst, int16_t **samples, int num, int channels)
 	if (count <= 0)
 		return count;
 
+	display_iq(buff, count);
+
 	for (c = 0; c < channels; c++) {
 		rot = sdr->chan[c].rx_rot;
 		phase = sdr->chan[c].rx_phase;

src/common/sender.h

@@ -7,7 +7,7 @@
 #include "jitter.h"
 #include "loss.h"
 #include "emphasis.h"
-#include "display_wave.h"
+#include "display.h"
 
 #define MAX_SENDER	16