Module: xenomai-abe
Branch: analogy
Commit: bee38acc8bed264547102a3013c76408235485e7
URL:
http://git.xenomai.org/?p=xenomai-abe.git;a=commit;h=bee38acc8bed264547102a3013c76408235485e7
Author: Alexis Berlemont <alexis.berlem...@gmail.com>
Date: Sat Oct 16 14:59:54 2010 +0200
analogy: add first version of waveform generation
This work is based on Daniele Nicolodi's work. Unfortunately, I could
not include the proprosal as is because it was limited for 16bits
acquisition devices.
So far, this work is not complete.
---
src/utils/analogy/Makefile.am | 6 ++
src/utils/analogy/signal_generation.c | 157 +++++++++++++++++++++++++++++++++
src/utils/analogy/signal_generation.h | 38 ++++++++
3 files changed, 201 insertions(+), 0 deletions(-)
diff --git a/src/utils/analogy/Makefile.am b/src/utils/analogy/Makefile.am
index f82942e..3d8cb5e 100644
--- a/src/utils/analogy/Makefile.am
+++ b/src/utils/analogy/Makefile.am
@@ -9,6 +9,12 @@ CPPFLAGS = \
LDFLAGS = \
@XENO_USER_LDFLAGS@
+lib_LIBRARIES = libwaveform.a
+
+libwaveform_a_SOURCES = signal_generation.c
+
+noinst_HEADERS = signal_generation.h
+
analogy_config_SOURCES = analogy_config.c
analogy_config_LDADD = \
../../drvlib/analogy/libanalogy.la \
diff --git a/src/utils/analogy/signal_generation.c
b/src/utils/analogy/signal_generation.c
new file mode 100644
index 0000000..2f443c5
--- /dev/null
+++ b/src/utils/analogy/signal_generation.c
@@ -0,0 +1,157 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <errno.h>
+#include <math.h>
+
+#include <analogy/analogy.h>
+
+#include "signal_generation.h"
+
+#ifndef PI
+#define PI 3.14159265358979323846
+#endif
+
+void a4l_sg_init_sine(struct waveform_config *config, double *values)
+{
+ int i;
+
+ double ratio = config->wf_frequency / config->spl_frequency;
+
+ for (i = 0; i < config->spl_count; i++) {
+
+ values[i] = config->wf_offset -
+ config->wf_amplitude / 2 +
+ 0.5 * config->wf_amplitude * cos(i * 2 * PI * ratio);
+ }
+}
+
+void a4l_sg_init_sawtooth(struct waveform_config *config, double *values)
+{
+ int i;
+
+ double ratio = config->wf_frequency / config->spl_frequency;
+
+ for (i = 0; i < config->spl_count; i++) {
+
+ int period_idx = (int)floor(i * ratio);
+
+ values[i] = config->wf_offset -
+ config->wf_amplitude / 2 -
+ period_idx * config->wf_amplitude +
+ i * ratio * config->wf_amplitude;
+ }
+}
+
+void a4l_sg_init_triangular(struct waveform_config *config, double *values)
+{
+ int i;
+
+ double ratio = config->wf_frequency / config->spl_frequency;
+
+ for (i = 0; i < config->spl_count; i++) {
+
+ int period_idx = (int)floor(i * ratio);
+ int half_period_idx = (int)floor(i * 2 * ratio);
+ int rise = ((half_period_idx % 2) == 0) ? 1 : 0;
+
+ if (rise) {
+ values[i] = config->wf_offset -
+ config->wf_amplitude / 2 -
+ 2 * period_idx * config->wf_amplitude +
+ 2 * i * ratio * config->wf_amplitude;
+ } else {
+ values[i] = config->wf_offset -
+ config->wf_amplitude / 2 +
+ 2 * (period_idx + 1) * config->wf_amplitude -
+ 2 * i * ratio * config->wf_amplitude;
+ }
+ }
+}
+
+void a4l_sg_init_steps(struct waveform_config *config, double *values)
+{
+ int i;
+
+ double ratio = config->wf_frequency / config->spl_frequency;
+
+ for (i = 0; i < config->spl_count; i++) {
+ int half_period_idx = (int)floor(i * 2 * ratio);
+ int even = (half_period_idx % 2 == 0);
+
+ values[i] = config->wf_offset -
+ config->wf_amplitude / 2 + even * config->wf_amplitude;
+ }
+}
+
+void a4l_sg_set_sample_count(struct waveform_config *config)
+{
+ int sample_count = MIN_SAMPLE_COUNT;
+ int best_count = MIN_SAMPLE_COUNT;
+ double lowest_diff = INFINITY;
+
+ while (sample_count < MAX_SAMPLE_COUNT) {
+
+ double ratio = (double)sample_count *
+ (config->wf_frequency / config->spl_frequency);
+ int ceiling = ceil(ratio);
+ double diff = (double)ceiling - ratio;
+
+ assert(diff >= 0);
+
+ if (diff < lowest_diff) {
+ lowest_diff = diff;
+ best_count = sample_count;
+ }
+
+ if (diff == 0)
+ break;
+
+ sample_count++;
+ }
+
+ if (lowest_diff != 0) {
+ printf("Warning: unable to create a contiguous signal\n");
+ printf("Warning: an approximation is performed\n");
+ }
+
+ config->spl_count = best_count;
+}
+
+int a4l_sg_check_config(struct waveform_config *config)
+{
+
+ if (config->wf_amplitude == 0)
+ printf("Warning: the signal will be constant\n");
+
+ if (config->wf_frequency * 2 > config->spl_frequency) {
+ printf("Error: the sampling frequency is not correct\n");
+ printf("Error: sampling frequency >= 2 * signal frequency\n");
+ return -EINVAL;
+ }
+
+ /* TODO: check with find_range */
+
+ return 0;
+}
+
+static void (* init_values[])(struct waveform_config *, double *) = {
+ a4l_sg_init_sine,
+ a4l_sg_init_sawtooth,
+ a4l_sg_init_triangular,
+ a4l_sg_init_steps,
+};
+
+void a4l_sg_init_values(struct waveform_config *config, double *values)
+{
+ init_values[config->wf_kind](config, values);
+}
+
+void a4l_sg_dump_values(struct waveform_config *config, double *values)
+{
+ int i;
+
+ for (i = 0; i < config->spl_count; i++)
+ printf("%f\n", values[i]);
+}
+
diff --git a/src/utils/analogy/signal_generation.h
b/src/utils/analogy/signal_generation.h
new file mode 100644
index 0000000..6f6d2cf
--- /dev/null
+++ b/src/utils/analogy/signal_generation.h
@@ -0,0 +1,38 @@
+#ifndef __SIGNAL_GENERATION_H__
+#define __SIGNAL_GENERATION_H__
+
+#include <stdio.h>
+
+#include <analogy/analogy.h>
+
+#define MAX_SAMPLE_COUNT 8096
+#define MIN_SAMPLE_COUNT 2
+
+#define WAVEFORM_SINE 0
+#define WAVEFORM_SAWTOOTH 1
+#define WAVEFORM_TRIANGULAR 2
+#define WAVEFORM_STEPS 3
+
+struct waveform_config {
+
+ /* Waveform stuff */
+ int wf_kind;
+ double wf_frequency;
+ double wf_amplitude;
+ double wf_offset;
+
+ /* Sampling stuff */
+ double spl_frequency;
+ int spl_count;
+};
+
+void a4l_sg_init_sine(struct waveform_config *config, double *values);
+void a4l_sg_init_sawtooth(struct waveform_config *config, double *values);
+void a4l_sg_init_triangular(struct waveform_config *config, double *values);
+void a4l_sg_init_steps(struct waveform_config *config, double *values);
+void a4l_sg_set_sample_count(struct waveform_config *config);
+int a4l_sg_check_config(struct waveform_config *config);
+void a4l_sg_init_values(struct waveform_config *config, double *values);
+void a4l_sg_dump_values(struct waveform_config *config, double *values);
+
+#endif /* __SIGNAL_GENERATION_H__ */
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