2 * Copyright © 2011 Keith Packard <keithp@keithp.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
19 #ifndef AO_FLIGHT_TEST
25 #include <ao_quaternion.h>
29 * Current sensor values
33 #define PRES_TYPE int32_t
34 #define ALT_TYPE int32_t
35 #define ACCEL_TYPE int16_t
38 __pdata uint16_t ao_sample_tick; /* time of last data */
39 __pdata pres_t ao_sample_pres;
40 __pdata alt_t ao_sample_alt;
41 __pdata alt_t ao_sample_height;
43 __pdata accel_t ao_sample_accel;
46 __pdata accel_t ao_sample_accel_along;
47 __pdata accel_t ao_sample_accel_across;
48 __pdata accel_t ao_sample_accel_through;
49 __pdata gyro_t ao_sample_roll;
50 __pdata gyro_t ao_sample_pitch;
51 __pdata gyro_t ao_sample_yaw;
52 __pdata angle_t ao_sample_orient;
55 __data uint8_t ao_sample_data;
58 * Sensor calibration values
61 __pdata pres_t ao_ground_pres; /* startup pressure */
62 __pdata alt_t ao_ground_height; /* MSL of ao_ground_pres */
65 __pdata accel_t ao_ground_accel; /* startup acceleration */
66 __pdata accel_t ao_accel_2g; /* factory accel calibration */
67 __pdata int32_t ao_accel_scale; /* sensor to m/s² conversion */
71 __pdata accel_t ao_ground_accel_along;
72 __pdata accel_t ao_ground_accel_across;
73 __pdata accel_t ao_ground_accel_through;
74 __pdata int32_t ao_ground_pitch;
75 __pdata int32_t ao_ground_yaw;
76 __pdata int32_t ao_ground_roll;
79 static __pdata uint8_t ao_preflight; /* in preflight mode */
81 static __pdata uint16_t nsamples;
82 __pdata int32_t ao_sample_pres_sum;
84 __pdata int32_t ao_sample_accel_sum;
87 __pdata int32_t ao_sample_accel_along_sum;
88 __pdata int32_t ao_sample_accel_across_sum;
89 __pdata int32_t ao_sample_accel_through_sum;
90 __pdata int32_t ao_sample_pitch_sum;
91 __pdata int32_t ao_sample_yaw_sum;
92 __pdata int32_t ao_sample_roll_sum;
93 static struct ao_quaternion ao_rotation;
97 extern uint8_t ao_orient_test;
101 ao_sample_preflight_add(void)
104 ao_sample_accel_sum += ao_sample_accel;
106 ao_sample_pres_sum += ao_sample_pres;
108 ao_sample_accel_along_sum += ao_sample_accel_along;
109 ao_sample_accel_across_sum += ao_sample_accel_across;
110 ao_sample_accel_through_sum += ao_sample_accel_through;
111 ao_sample_pitch_sum += ao_sample_pitch;
112 ao_sample_yaw_sum += ao_sample_yaw;
113 ao_sample_roll_sum += ao_sample_roll;
119 ao_sample_preflight_set(void)
122 ao_ground_accel = ao_sample_accel_sum >> 9;
123 ao_sample_accel_sum = 0;
125 ao_ground_pres = ao_sample_pres_sum >> 9;
126 ao_ground_height = pres_to_altitude(ao_ground_pres);
127 ao_sample_pres_sum = 0;
129 ao_ground_accel_along = ao_sample_accel_along_sum >> 9;
130 ao_ground_accel_across = ao_sample_accel_across_sum >> 9;
131 ao_ground_accel_through = ao_sample_accel_through_sum >> 9;
132 ao_ground_pitch = ao_sample_pitch_sum;
133 ao_ground_yaw = ao_sample_yaw_sum;
134 ao_ground_roll = ao_sample_roll_sum;
135 ao_sample_accel_along_sum = 0;
136 ao_sample_accel_across_sum = 0;
137 ao_sample_accel_through_sum = 0;
138 ao_sample_pitch_sum = 0;
139 ao_sample_yaw_sum = 0;
140 ao_sample_roll_sum = 0;
141 ao_sample_orient = 0;
143 struct ao_quaternion orient;
145 /* Take the pad IMU acceleration values and compute our current direction
148 ao_quaternion_init_vector(&orient,
149 (ao_ground_accel_across - ao_config.accel_zero_across),
150 (ao_ground_accel_through - ao_config.accel_zero_through),
151 (ao_ground_accel_along - ao_config.accel_zero_along));
153 ao_quaternion_normalize(&orient,
158 struct ao_quaternion up = { .r = 0, .x = 0, .y = 0, .z = 1 };
160 if (ao_config.pad_orientation != AO_PAD_ORIENTATION_ANTENNA_UP)
163 /* Compute rotation to get from up to our current orientation, set
164 * that as the current rotation vector
166 ao_quaternion_vectors_to_rotation(&ao_rotation, &up, &orient);
169 printf("\n\treset\n");
177 #define TIME_DIV 200.0f
180 ao_sample_rotate(void)
182 #ifdef AO_FLIGHT_TEST
183 float dt = (ao_sample_tick - ao_sample_prev_tick) / TIME_DIV;
185 static const float dt = 1/TIME_DIV;
187 float x = ao_mpu6000_gyro((float) ((ao_sample_pitch << 9) - ao_ground_pitch) / 512.0f) * dt;
188 float y = ao_mpu6000_gyro((float) ((ao_sample_yaw << 9) - ao_ground_yaw) / 512.0f) * dt;
189 float z = ao_mpu6000_gyro((float) ((ao_sample_roll << 9) - ao_ground_roll) / 512.0f) * dt;
190 struct ao_quaternion rot;
192 ao_quaternion_init_half_euler(&rot, x, y, z);
193 ao_quaternion_multiply(&ao_rotation, &rot, &ao_rotation);
195 /* And normalize to make sure it remains a unit vector */
196 ao_quaternion_normalize(&ao_rotation, &ao_rotation);
198 /* Compute pitch angle from vertical by taking the pad
199 * orientation vector and rotating it by the current total
200 * rotation value. That will be a unit vector pointing along
201 * the airframe axis. The Z value will be the cosine of the
202 * change in the angle from vertical since boost.
204 * rot = ao_rotation * vertical * ao_rotation°
205 * rot = ao_rotation * (0,0,0,1) * ao_rotation°
206 * = ((a.z, a.y, -a.x, a.r) * (a.r, -a.x, -a.y, -a.z)) .z
208 * = (-a.z * -a.z) + (a.y * -a.y) - (-a.x * -a.x) + (a.r * a.r)
209 * = a.z² - a.y² - a.x² + a.r²
211 * rot = ao_rotation * (0, 0, 0, -1) * ao_rotation°
212 * = ((-a.z, -a.y, a.x, -a.r) * (a.r, -a.x, -a.y, -a.z)) .z
214 * = (a.z * -a.z) + (-a.y * -a.y) - (a.x * -a.x) + (-a.r * a.r)
215 * = -a.z² + a.y² + a.x² - a.r²
219 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;
221 ao_sample_orient = acosf(rotz) * (float) (180.0/M_PI);
224 if (ao_orient_test) {
225 printf ("rot %d %d %d orient %d \r",
237 ao_sample_preflight(void)
241 * Collect 512 samples of acceleration and pressure
242 * data and average them to find the resting values
244 if (nsamples < 512) {
245 ao_sample_preflight_add();
248 ao_accel_2g = ao_config.accel_minus_g - ao_config.accel_plus_g;
249 ao_accel_scale = to_fix_32(GRAVITY * 2 * 16) / ao_accel_2g;
251 ao_sample_preflight_set();
252 ao_preflight = FALSE;
257 * While in pad mode, constantly update the ground state by
258 * re-averaging the data. This tracks changes in orientation, which
259 * might be caused by adjustments to the rocket on the pad and
260 * pressure, which might be caused by changes in the weather.
264 ao_sample_preflight_update(void)
267 ao_sample_preflight_add();
268 else if (nsamples < 1024)
271 ao_sample_preflight_set();
276 static int32_t p_filt;
277 static int32_t y_filt;
279 static gyro_t inline ao_gyro(void) {
280 gyro_t p = ao_sample_pitch - ao_ground_pitch;
281 gyro_t y = ao_sample_yaw - ao_ground_yaw;
283 p_filt = p_filt - (p_filt >> 6) + p;
284 y_filt = y_filt - (y_filt >> 6) + y;
288 return ao_sqrt(p*p + y*y);
296 ao_wakeup(DATA_TO_XDATA(&ao_sample_data));
297 ao_sleep((void *) DATA_TO_XDATA(&ao_data_head));
298 while (ao_sample_data != ao_data_head) {
299 __xdata struct ao_data *ao_data;
301 /* Capture a sample */
302 ao_data = (struct ao_data *) &ao_data_ring[ao_sample_data];
303 ao_sample_tick = ao_data->tick;
306 ao_data_pres_cook(ao_data);
307 ao_sample_pres = ao_data_pres(ao_data);
308 ao_sample_alt = pres_to_altitude(ao_sample_pres);
309 ao_sample_height = ao_sample_alt - ao_ground_height;
313 ao_sample_accel = ao_data_accel_cook(ao_data);
314 if (ao_config.pad_orientation != AO_PAD_ORIENTATION_ANTENNA_UP)
315 ao_sample_accel = ao_data_accel_invert(ao_sample_accel);
316 ao_data_set_accel(ao_data, ao_sample_accel);
319 ao_sample_accel_along = ao_data_along(ao_data);
320 ao_sample_accel_across = ao_data_across(ao_data);
321 ao_sample_accel_through = ao_data_through(ao_data);
322 ao_sample_pitch = ao_data_pitch(ao_data);
323 ao_sample_yaw = ao_data_yaw(ao_data);
324 ao_sample_roll = ao_data_roll(ao_data);
328 ao_sample_preflight();
330 if (ao_flight_state < ao_flight_boost)
331 ao_sample_preflight_update();
337 #ifdef AO_FLIGHT_TEST
338 ao_sample_prev_tick = ao_sample_tick;
340 ao_sample_data = ao_data_ring_next(ao_sample_data);
342 return !ao_preflight;
350 ao_sample_pres_sum = 0;
353 ao_sample_accel_sum = 0;
357 ao_sample_accel_along_sum = 0;
358 ao_sample_accel_across_sum = 0;
359 ao_sample_accel_through_sum = 0;
360 ao_sample_accel_along = 0;
361 ao_sample_accel_across = 0;
362 ao_sample_accel_through = 0;
363 ao_sample_pitch_sum = 0;
364 ao_sample_yaw_sum = 0;
365 ao_sample_roll_sum = 0;
369 ao_sample_orient = 0;
371 ao_sample_data = ao_data_head;