--- /dev/null
+/*
+ * Copyright © 2011 Keith Packard <keithp@keithp.com>
+ *
+ * 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; version 2 of the License.
+ *
+ * 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, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#ifndef AO_FLIGHT_TEST
+#include "ao.h"
+#include <ao_data.h>
+#endif
+
+#if HAS_GYRO
+#include <ao_quaternion.h>
+#endif
+
+/*
+ * Current sensor values
+ */
+
+#ifndef PRES_TYPE
+#define PRES_TYPE int32_t
+#define ALT_TYPE int32_t
+#define ACCEL_TYPE int16_t
+#endif
+
+__pdata uint16_t ao_sample_tick; /* time of last data */
+__pdata pres_t ao_sample_pres;
+__pdata alt_t ao_sample_alt;
+__pdata alt_t ao_sample_height;
+#if HAS_ACCEL
+__pdata accel_t ao_sample_accel;
+#endif
+#if HAS_GYRO
+__pdata accel_t ao_sample_accel_along;
+__pdata accel_t ao_sample_accel_across;
+__pdata accel_t ao_sample_accel_through;
+__pdata gyro_t ao_sample_roll;
+__pdata gyro_t ao_sample_pitch;
+__pdata gyro_t ao_sample_yaw;
+__pdata angle_t ao_sample_orient;
+#endif
+
+__data uint8_t ao_sample_data;
+
+/*
+ * Sensor calibration values
+ */
+
+__pdata pres_t ao_ground_pres; /* startup pressure */
+__pdata alt_t ao_ground_height; /* MSL of ao_ground_pres */
+
+#if HAS_ACCEL
+__pdata accel_t ao_ground_accel; /* startup acceleration */
+__pdata accel_t ao_accel_2g; /* factory accel calibration */
+__pdata int32_t ao_accel_scale; /* sensor to m/s² conversion */
+#endif
+
+#if HAS_GYRO
+__pdata accel_t ao_ground_accel_along;
+__pdata accel_t ao_ground_accel_across;
+__pdata accel_t ao_ground_accel_through;
+__pdata int32_t ao_ground_pitch;
+__pdata int32_t ao_ground_yaw;
+__pdata int32_t ao_ground_roll;
+#endif
+
+static __pdata uint8_t ao_preflight; /* in preflight mode */
+
+static __pdata uint16_t nsamples;
+__pdata int32_t ao_sample_pres_sum;
+#if HAS_ACCEL
+__pdata int32_t ao_sample_accel_sum;
+#endif
+#if HAS_GYRO
+__pdata int32_t ao_sample_accel_along_sum;
+__pdata int32_t ao_sample_accel_across_sum;
+__pdata int32_t ao_sample_accel_through_sum;
+__pdata int32_t ao_sample_pitch_sum;
+__pdata int32_t ao_sample_yaw_sum;
+__pdata int32_t ao_sample_roll_sum;
+static struct ao_quaternion ao_rotation;
+#endif
+
+#if HAS_FLIGHT_DEBUG
+extern uint8_t ao_orient_test;
+#endif
+
+static void
+ao_sample_preflight_add(void)
+{
+#if HAS_ACCEL
+ ao_sample_accel_sum += ao_sample_accel;
+#endif
+ ao_sample_pres_sum += ao_sample_pres;
+#if HAS_GYRO
+ ao_sample_accel_along_sum += ao_sample_accel_along;
+ ao_sample_accel_across_sum += ao_sample_accel_across;
+ ao_sample_accel_through_sum += ao_sample_accel_through;
+ ao_sample_pitch_sum += ao_sample_pitch;
+ ao_sample_yaw_sum += ao_sample_yaw;
+ ao_sample_roll_sum += ao_sample_roll;
+#endif
+ ++nsamples;
+}
+
+static void
+ao_sample_preflight_set(void)
+{
+#if HAS_ACCEL
+ ao_ground_accel = ao_sample_accel_sum >> 9;
+ ao_sample_accel_sum = 0;
+#endif
+ ao_ground_pres = ao_sample_pres_sum >> 9;
+ ao_ground_height = pres_to_altitude(ao_ground_pres);
+ ao_sample_pres_sum = 0;
+#if HAS_GYRO
+ ao_ground_accel_along = ao_sample_accel_along_sum >> 9;
+ ao_ground_accel_across = ao_sample_accel_across_sum >> 9;
+ ao_ground_accel_through = ao_sample_accel_through_sum >> 9;
+ ao_ground_pitch = ao_sample_pitch_sum;
+ ao_ground_yaw = ao_sample_yaw_sum;
+ ao_ground_roll = ao_sample_roll_sum;
+ ao_sample_accel_along_sum = 0;
+ ao_sample_accel_across_sum = 0;
+ ao_sample_accel_through_sum = 0;
+ ao_sample_pitch_sum = 0;
+ ao_sample_yaw_sum = 0;
+ ao_sample_roll_sum = 0;
+ ao_sample_orient = 0;
+
+ struct ao_quaternion orient;
+
+ /* Take the pad IMU acceleration values and compute our current direction
+ */
+
+ ao_quaternion_init_vector(&orient,
+ (ao_ground_accel_across - ao_config.accel_zero_across),
+ (ao_ground_accel_through - ao_config.accel_zero_through),
+ (ao_ground_accel_along - ao_config.accel_zero_along));
+
+ ao_quaternion_normalize(&orient,
+ &orient);
+
+ /* Here's up */
+
+ struct ao_quaternion up = { .r = 0, .x = 0, .y = 0, .z = 1 };
+
+ if (ao_config.pad_orientation != AO_PAD_ORIENTATION_ANTENNA_UP)
+ up.z = -1;
+
+ /* Compute rotation to get from up to our current orientation, set
+ * that as the current rotation vector
+ */
+ ao_quaternion_vectors_to_rotation(&ao_rotation, &up, &orient);
+#if HAS_FLIGHT_DEBUG
+ if (ao_orient_test)
+ printf("\n\treset\n");
+#endif
+#endif
+ nsamples = 0;
+}
+
+#if HAS_GYRO
+
+#define TIME_DIV 200.0f
+
+static void
+ao_sample_rotate(void)
+{
+#ifdef AO_FLIGHT_TEST
+ float dt = (ao_sample_tick - ao_sample_prev_tick) / TIME_DIV;
+#else
+ static const float dt = 1/TIME_DIV;
+#endif
+ float x = ao_mpu6000_gyro((float) ((ao_sample_pitch << 9) - ao_ground_pitch) / 512.0f) * dt;
+ float y = ao_mpu6000_gyro((float) ((ao_sample_yaw << 9) - ao_ground_yaw) / 512.0f) * dt;
+ float z = ao_mpu6000_gyro((float) ((ao_sample_roll << 9) - ao_ground_roll) / 512.0f) * dt;
+ struct ao_quaternion rot;
+
+ ao_quaternion_init_half_euler(&rot, x, y, z);
+ ao_quaternion_multiply(&ao_rotation, &rot, &ao_rotation);
+
+ /* And normalize to make sure it remains a unit vector */
+ ao_quaternion_normalize(&ao_rotation, &ao_rotation);
+
+ /* Compute pitch angle from vertical by taking the pad
+ * orientation vector and rotating it by the current total
+ * rotation value. That will be a unit vector pointing along
+ * the airframe axis. The Z value will be the cosine of the
+ * change in the angle from vertical since boost.
+ *
+ * rot = ao_rotation * vertical * ao_rotation°
+ * rot = ao_rotation * (0,0,0,1) * ao_rotation°
+ * = ((a.z, a.y, -a.x, a.r) * (a.r, -a.x, -a.y, -a.z)) .z
+ *
+ * = (-a.z * -a.z) + (a.y * -a.y) - (-a.x * -a.x) + (a.r * a.r)
+ * = a.z² - a.y² - a.x² + a.r²
+ *
+ * rot = ao_rotation * (0, 0, 0, -1) * ao_rotation°
+ * = ((-a.z, -a.y, a.x, -a.r) * (a.r, -a.x, -a.y, -a.z)) .z
+ *
+ * = (a.z * -a.z) + (-a.y * -a.y) - (a.x * -a.x) + (-a.r * a.r)
+ * = -a.z² + a.y² + a.x² - a.r²
+ */
+
+ float rotz;
+ rotz = ao_rotation.z * ao_rotation.z - ao_rotation.y * ao_rotation.y - ao_rotation.x * ao_rotation.x + ao_rotation.r * ao_rotation.r;
+
+ ao_sample_orient = acosf(rotz) * (float) (180.0/M_PI);
+
+#if HAS_FLIGHT_DEBUG
+ if (ao_orient_test) {
+ printf ("rot %d %d %d orient %d \r",
+ (int) (x * 1000),
+ (int) (y * 1000),
+ (int) (z * 1000),
+ ao_sample_orient);
+ }
+#endif
+
+}
+#endif
+
+static void
+ao_sample_preflight(void)
+{
+ /* startup state:
+ *
+ * Collect 512 samples of acceleration and pressure
+ * data and average them to find the resting values
+ */
+ if (nsamples < 512) {
+ ao_sample_preflight_add();
+ } else {
+#if HAS_ACCEL
+ ao_accel_2g = ao_config.accel_minus_g - ao_config.accel_plus_g;
+ ao_accel_scale = to_fix32(GRAVITY * 2 * 16) / ao_accel_2g;
+#endif
+ ao_sample_preflight_set();
+ ao_preflight = FALSE;
+ }
+}
+
+/*
+ * While in pad mode, constantly update the ground state by
+ * re-averaging the data. This tracks changes in orientation, which
+ * might be caused by adjustments to the rocket on the pad and
+ * pressure, which might be caused by changes in the weather.
+ */
+
+static void
+ao_sample_preflight_update(void)
+{
+ if (nsamples < 512)
+ ao_sample_preflight_add();
+ else if (nsamples < 1024)
+ ++nsamples;
+ else
+ ao_sample_preflight_set();
+}
+
+#if 0
+#if HAS_GYRO
+static int32_t p_filt;
+static int32_t y_filt;
+
+static gyro_t inline ao_gyro(void) {
+ gyro_t p = ao_sample_pitch - ao_ground_pitch;
+ gyro_t y = ao_sample_yaw - ao_ground_yaw;
+
+ p_filt = p_filt - (p_filt >> 6) + p;
+ y_filt = y_filt - (y_filt >> 6) + y;
+
+ p = p_filt >> 6;
+ y = y_filt >> 6;
+ return ao_sqrt(p*p + y*y);
+}
+#endif
+#endif
+
+uint8_t
+ao_sample(void)
+{
+ ao_wakeup(DATA_TO_XDATA(&ao_sample_data));
+ ao_sleep((void *) DATA_TO_XDATA(&ao_data_head));
+ while (ao_sample_data != ao_data_head) {
+ __xdata struct ao_data *ao_data;
+
+ /* Capture a sample */
+ ao_data = (struct ao_data *) &ao_data_ring[ao_sample_data];
+ ao_sample_tick = ao_data->tick;
+
+#if HAS_BARO
+ ao_data_pres_cook(ao_data);
+ ao_sample_pres = ao_data_pres(ao_data);
+ ao_sample_alt = pres_to_altitude(ao_sample_pres);
+ ao_sample_height = ao_sample_alt - ao_ground_height;
+#endif
+
+#if HAS_ACCEL
+ ao_sample_accel = ao_data_accel_cook(ao_data);
+ if (ao_config.pad_orientation != AO_PAD_ORIENTATION_ANTENNA_UP)
+ ao_sample_accel = ao_data_accel_invert(ao_sample_accel);
+ ao_data_set_accel(ao_data, ao_sample_accel);
+#endif
+#if HAS_GYRO
+ ao_sample_accel_along = ao_data_along(ao_data);
+ ao_sample_accel_across = ao_data_across(ao_data);
+ ao_sample_accel_through = ao_data_through(ao_data);
+ ao_sample_pitch = ao_data_pitch(ao_data);
+ ao_sample_yaw = ao_data_yaw(ao_data);
+ ao_sample_roll = ao_data_roll(ao_data);
+#endif
+
+ if (ao_preflight)
+ ao_sample_preflight();
+ else {
+ if (ao_flight_state < ao_flight_boost)
+ ao_sample_preflight_update();
+ ao_kalman();
+#if HAS_GYRO
+ ao_sample_rotate();
+#endif
+ }
+#ifdef AO_FLIGHT_TEST
+ ao_sample_prev_tick = ao_sample_tick;
+#endif
+ ao_sample_data = ao_data_ring_next(ao_sample_data);
+ }
+ return !ao_preflight;
+}
+
+void
+ao_sample_init(void)
+{
+ ao_config_get();
+ nsamples = 0;
+ ao_sample_pres_sum = 0;
+ ao_sample_pres = 0;
+#if HAS_ACCEL
+ ao_sample_accel_sum = 0;
+ ao_sample_accel = 0;
+#endif
+#if HAS_GYRO
+ ao_sample_accel_along_sum = 0;
+ ao_sample_accel_across_sum = 0;
+ ao_sample_accel_through_sum = 0;
+ ao_sample_accel_along = 0;
+ ao_sample_accel_across = 0;
+ ao_sample_accel_through = 0;
+ ao_sample_pitch_sum = 0;
+ ao_sample_yaw_sum = 0;
+ ao_sample_roll_sum = 0;
+ ao_sample_pitch = 0;
+ ao_sample_yaw = 0;
+ ao_sample_roll = 0;
+ ao_sample_orient = 0;
+#endif
+ ao_sample_data = ao_data_head;
+ ao_preflight = TRUE;
+}
projects / fw / altos / blobdiff