unsigned int sample_size;
};
-static unsigned int partition(float* list, unsigned int left,
- unsigned int right, unsigned int pivot_index)
+
+static unsigned int partition ( float* list, unsigned int left,
+ unsigned int right, unsigned int pivot_index)
{
unsigned int i;
unsigned int store_index = left;
float aux;
float pivot_value = list[pivot_index];
- // swap list[pivotIndex] and list[right]
+ /* Swap list[pivotIndex] and list[right] */
aux = list[pivot_index];
list[pivot_index] = list[right];
list[right] = aux;
{
if (list[i] < pivot_value)
{
- // swap list[store_index] and list[i]
+ /* Swap list[store_index] and list[i] */
aux = list[store_index];
list[store_index] = list[i];
list[i] = aux;
store_index++;
}
}
- //swap list[right] and list[store_index]
+
+ /* Swap list[right] and list[store_index] */
aux = list[right];
list[right] = list[store_index];
list[store_index] = aux;
return store_index;
}
-/* http://en.wikipedia.org/wiki/Quickselect */
-float median(float* queue, unsigned int size)
+
+static float median (float* queue, unsigned int size)
{
+ /* http://en.wikipedia.org/wiki/Quickselect */
+
unsigned int left = 0;
unsigned int right = size - 1;
unsigned int pivot_index;
return temp[left];
}
-void denoise_median_init(int s, unsigned int num_fields,
- unsigned int max_samples)
+
+static void denoise_median_init(int s, unsigned int num_fields,
+ unsigned int max_samples)
{
- struct filter_median* f_data = (struct filter_median*) calloc(1, sizeof(struct filter_median));
+ struct filter_median* f_data = (struct filter_median*) calloc(1,
+ sizeof(struct filter_median));
+
f_data->buff = (float*)calloc(max_samples,
sizeof(float) * num_fields);
f_data->sample_size = max_samples;
sensor_info[s].filter = f_data;
}
-static void denoise_median_reset(struct sensor_info_t* info)
+
+static void denoise_median_reset (struct sensor_info_t* info)
{
struct filter_median* f_data = (struct filter_median*) info->filter;
f_data->idx = 0;
}
-void denoise_median_release(int s)
-{
- if (!sensor_info[s].filter)
- return;
-
- free(((struct filter_median*)sensor_info[s].filter)->buff);
- free(sensor_info[s].filter);
- sensor_info[s].filter = NULL;
-}
-void denoise_median(struct sensor_info_t* info, struct sensors_event_t* data,
- unsigned int num_fields)
+static void denoise_median ( struct sensor_info_t* info,
+ struct sensors_event_t* data,
+ unsigned int num_fields)
{
float x, y, z;
float scale;
if (!f_data)
return;
- /* If we are at event count 1 reset the indexes */
+ /* If we are at event count 1 reset the indices */
if (info->event_count == 1)
denoise_median_reset(info);
}
-#define GLOBAL_HISTORY_SIZE 100
-
-struct recorded_sample_t
-{
- int sensor;
- int motion_trigger;
- sensors_event_t data;
-};
-
-/*
- * This is a circular buffer holding the last GLOBAL_HISTORY_SIZE events,
- * covering the entire sensor collection. It is intended as a way to correlate
- * data coming from active sensors, no matter the sensor type, over a recent
- * window of time. The array is not sorted ; we simply evict the oldest cell
- * (by insertion time) and replace its contents. Timestamps don't necessarily
- * grow monotonically as they tell the data acquisition type, and that there can
- * be a delay between acquisition and insertion into this table.
- */
-
-static struct recorded_sample_t global_history[GLOBAL_HISTORY_SIZE];
-
-static int initialized_entries; /* How many of these are initialized */
-static int insertion_index; /* Index of sample to evict next time */
-
-
-void record_sample (int s, const struct sensors_event_t* event)
-{
- struct recorded_sample_t *cell;
- int i;
-
- /* Don't record duplicate samples, as they are not useful for filters */
- if (sensor_info[s].report_pending == DATA_DUPLICATE)
- return;
-
- if (initialized_entries == GLOBAL_HISTORY_SIZE) {
- i = insertion_index;
- insertion_index = (insertion_index+1) % GLOBAL_HISTORY_SIZE;
- } else {
- i = initialized_entries;
- initialized_entries++;
- }
-
- cell = &global_history[i];
-
- cell->sensor = s;
-
- cell->motion_trigger = (sensor_info[s].selected_trigger ==
- sensor_info[s].motion_trigger_name);
-
- memcpy(&cell->data, event, sizeof(sensors_event_t));
-}
-
-
-void denoise_average ( struct sensor_info_t* si, struct sensors_event_t* data,
- int num_fields, int max_samples)
+static void denoise_average ( struct sensor_info_t* si,
+ struct sensors_event_t* data,
+ int num_fields, int max_samples)
{
/*
* Smooth out incoming data using a moving average over a number of
/* Update our rolling index (next evicted cell) */
si->history_index = (si->history_index + 1) % si->history_size;
}
+
+
+void setup_noise_filtering (int s)
+{
+ switch (sensor_info[s].type) {
+ case SENSOR_TYPE_GYROSCOPE:
+ case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
+ denoise_median_init(s, 3, 7);
+ break;
+ }
+}
+
+
+void denoise (int s, struct sensors_event_t* data)
+{
+ switch (sensor_info[s].type) {
+ case SENSOR_TYPE_GYROSCOPE:
+ case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
+ denoise_median(&sensor_info[s], data, 3);
+ break;
+
+ case SENSOR_TYPE_MAGNETIC_FIELD:
+ denoise_average(&sensor_info[s], data, 3 , 30);
+ break;
+ }
+}
+
+
+void release_noise_filtering_data (int s)
+{
+ void *buff;
+
+ /* Delete moving average structures */
+ if (sensor_info[s].history) {
+ free(sensor_info[s].history);
+ sensor_info[s].history = NULL;
+ sensor_info[s].history_size = 0;
+ if (sensor_info[s].history_sum) {
+ free(sensor_info[s].history_sum);
+ sensor_info[s].history_sum = NULL;
+ }
+ }
+
+ /* Delete median filter structures */
+ if (sensor_info[s].filter) {
+ buff = ((struct filter_median*)sensor_info[s].filter)->buff;
+
+ if (buff)
+ free(buff);
+
+ free(sensor_info[s].filter);
+ sensor_info[s].filter = NULL;
+ }
+}
+
+
+#define GLOBAL_HISTORY_SIZE 100
+
+struct recorded_sample_t
+{
+ int sensor;
+ int motion_trigger;
+ sensors_event_t data;
+};
+
+/*
+ * This is a circular buffer holding the last GLOBAL_HISTORY_SIZE events,
+ * covering the entire sensor collection. It is intended as a way to correlate
+ * data coming from active sensors, no matter the sensor type, over a recent
+ * window of time. The array is not sorted ; we simply evict the oldest cell
+ * (by insertion time) and replace its contents. Timestamps don't necessarily
+ * grow monotonically as they tell the data acquisition type, and that there can
+ * be a delay between acquisition and insertion into this table.
+ */
+
+static struct recorded_sample_t global_history[GLOBAL_HISTORY_SIZE];
+
+static int initialized_entries; /* How many of these are initialized */
+static int insertion_index; /* Index of sample to evict next time */
+
+
+void record_sample (int s, const struct sensors_event_t* event)
+{
+ struct recorded_sample_t *cell;
+ int i;
+
+ /* Don't record duplicate samples, as they are not useful for filters */
+ if (sensor_info[s].report_pending == DATA_DUPLICATE)
+ return;
+
+ if (initialized_entries == GLOBAL_HISTORY_SIZE) {
+ i = insertion_index;
+ insertion_index = (insertion_index+1) % GLOBAL_HISTORY_SIZE;
+ } else {
+ i = initialized_entries;
+ initialized_entries++;
+ }
+
+ cell = &global_history[i];
+
+ cell->sensor = s;
+
+ cell->motion_trigger = (sensor_info[s].selected_trigger ==
+ sensor_info[s].motion_trigger_name);
+
+ memcpy(&cell->data, event, sizeof(sensors_event_t));
+}
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