#include "description.h"
#include "transform.h"
#include "utils.h"
+#include "filtering.h"
/*----------------------------------------------------------------------------*/
}
-static int finalize_sample_default(int s, struct sensors_event_t* data)
+static void denoise (struct sensor_info_t* si, struct sensors_event_t* data,
+ int num_fields, int max_samples)
{
- int i = sensor_info[s].catalog_index;
- int sensor_type = sensor_catalog[i].type;
+ /*
+ * Smooth out incoming data using a moving average over a number of
+ * samples. We accumulate one second worth of samples, or max_samples,
+ * depending on which is lower.
+ */
+
+ int i;
+ int f;
+ int sampling_rate = (int) si->sampling_rate;
+ int history_size;
+ int history_full = 0;
+
+ /* Don't denoise anything if we have less than two samples per second */
+ if (sampling_rate < 2)
+ return;
+
+ /* Restrict window size to the min of sampling_rate and max_samples */
+ if (sampling_rate > max_samples)
+ history_size = max_samples;
+ else
+ history_size = sampling_rate;
+
+ /* Reset history if we're operating on an incorrect window size */
+ if (si->history_size != history_size) {
+ si->history_size = history_size;
+ si->history_entries = 0;
+ si->history_index = 0;
+ si->history = (float*) realloc(si->history,
+ si->history_size * num_fields * sizeof(float));
+ if (si->history) {
+ si->history_sum = (float*) realloc(si->history_sum,
+ num_fields * sizeof(float));
+ if (si->history_sum)
+ memset(si->history_sum, 0, num_fields * sizeof(float));
+ }
+ }
+
+ if (!si->history || !si->history_sum)
+ return; /* Unlikely, but still... */
+
+ /* Update initialized samples count */
+ if (si->history_entries < si->history_size)
+ si->history_entries++;
+ else
+ history_full = 1;
+
+ /* Record new sample and calculate the moving sum */
+ for (f=0; f < num_fields; f++) {
+ /**
+ * A field is going to be overwritten if
+ * history is full, so decrease the history sum
+ */
+ if (history_full)
+ si->history_sum[f] -=
+ si->history[si->history_index * num_fields + f];
+
+ si->history[si->history_index * num_fields + f] = data->data[f];
+ si->history_sum[f] += data->data[f];
+
+ /* For now simply compute a mobile mean for each field */
+ /* and output filtered data */
+ data->data[f] = si->history_sum[f] / si->history_entries;
+ }
+
+ /* Update our rolling index (next evicted cell) */
+ si->history_index = (si->history_index + 1) % si->history_size;
+}
+
+static int finalize_sample_default (int s, struct sensors_event_t* data)
+{
/* Swap fields if we have a custom channel ordering on this sensor */
if (sensor_info[s].quirks & QUIRK_FIELD_ORDERING)
reorder_fields(data->data, sensor_info[s].order);
- switch (sensor_type) {
+ sensor_info[s].event_count++;
+ switch (sensor_info[s].type) {
case SENSOR_TYPE_ACCELEROMETER:
+ /* Always consider the accelerometer accurate */
+ data->acceleration.status = SENSOR_STATUS_ACCURACY_HIGH;
+ if (sensor_info[s].quirks & QUIRK_NOISY)
+ denoise(&sensor_info[s], data, 3, 20);
break;
case SENSOR_TYPE_MAGNETIC_FIELD:
calibrate_compass (data, &sensor_info[s], get_timestamp());
+ if (sensor_info[s].quirks & QUIRK_NOISY)
+ denoise(&sensor_info[s], data, 3, 100);
break;
case SENSOR_TYPE_GYROSCOPE:
case SENSOR_TYPE_GYROSCOPE_UNCALIBRATED:
- calibrate_gyro(data, &sensor_info[s]);
+ /*
+ * Report medium accuracy by default ; higher accuracy
+ * levels will be reported once, and if, we achieve
+ * calibration.
+ */
+ data->gyro.status = SENSOR_STATUS_ACCURACY_MEDIUM;
+
+ /*
+ * We're only trying to calibrate data from continuously
+ * firing gyroscope drivers, as motion based ones use
+ * movement thresholds that may lead us to incorrectly
+ * estimate bias.
+ */
+ if (sensor_info[s].selected_trigger !=
+ sensor_info[s].motion_trigger_name)
+ calibrate_gyro(data, &sensor_info[s]);
+
+ /* For noisy sensors we'll drop a very few number
+ * of samples to make sure we have at least MIN_SAMPLES events
+ * in the filtering queue. This is to make sure we are not sending
+ * events that can disturb our mean or stddev.
+ */
+ if (sensor_info[s].quirks & QUIRK_NOISY) {
+ denoise_median(&sensor_info[s], data, 3);
+ if((sensor_info[s].selected_trigger !=
+ sensor_info[s].motion_trigger_name) &&
+ sensor_info[s].event_count < MIN_SAMPLES)
+ return 0;
+ }
break;
case SENSOR_TYPE_LIGHT:
break;
}
+ /* Add this event to our global records, for filtering purposes */
+ record_sample(s, data);
+
return 1; /* Return sample to Android */
}
}
-static int finalize_sample_ISH(int s, struct sensors_event_t* data)
+static int finalize_sample_ISH (int s, struct sensors_event_t* data)
{
- int i = sensor_info[s].catalog_index;
- int sensor_type = sensor_catalog[i].type;
float pitch, roll, yaw;
/* Swap fields if we have a custom channel ordering on this sensor */
if (sensor_info[s].quirks & QUIRK_FIELD_ORDERING)
reorder_fields(data->data, sensor_info[s].order);
- if (sensor_type == SENSOR_TYPE_ORIENTATION) {
+ if (sensor_info[s].type == SENSOR_TYPE_ORIENTATION) {
pitch = data->data[0];
roll = data->data[1];
data->data[2] = -roll;
}
+ /* Add this event to our global records, for filtering purposes */
+ record_sample(s, data);
+
return 1; /* Return sample to Android */
}
-static float transform_sample_ISH(int s, int c, unsigned char* sample_data)
+static float transform_sample_ISH (int s, int c, unsigned char* sample_data)
{
struct datum_info_t* sample_type = &sensor_info[s].channel[c].type_info;
int val = (int) sample_as_int64(sample_data, sample_type);
- int i = sensor_info[s].catalog_index;
- int sensor_type = sensor_catalog[i].type;
float correction;
int data_bytes = (sample_type->realbits)/8;
int exponent = sensor_info[s].offset;
/* In case correction has been requested using properties, apply it */
correction = sensor_info[s].channel[c].opt_scale;
- switch (sensor_type) {
+ switch (sensor_info[s].type) {
case SENSOR_TYPE_ACCELEROMETER:
switch (c) {
case 0: