Module: xenomai-head Branch: master Commit: bee38acc8bed264547102a3013c76408235485e7 URL: http://git.xenomai.org/?p=xenomai-head.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__ */ _______________________________________________ Xenomai-git mailing list Xenomai-git@gna.org https://mail.gna.org/listinfo/xenomai-git