2 * Copyright © 2013 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; version 2 of the License.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
18 #ifndef AO_FLIGHT_TEST
21 #include <ao_micropeak.h>
25 #define to_fix_v(x) ((int16_t) ((x) * 65536.0 + 0.5))
26 #define to_fix_k(x) ((int32_t) ((x) * 65536.0 + 0.5))
27 #define from_fix8(x) ((x) >> 8)
28 #define from_fix(x) ((x) >> 16)
29 #define fix8_to_fix_v(x) ((x) << 8)
30 #define fix16_to_fix8(x) ((x) >> 8)
32 #include <ao_kalman.h>
34 /* Basic time step (96ms) */
35 #define AO_MK_STEP to_fix_v(0.096)
37 #define AO_MK_STEP_2_2 to_fix_v(0.004608)
39 uint32_t ao_k_pa; /* 24.8 fixed point */
40 int32_t ao_k_pa_speed; /* 16.16 fixed point */
41 int32_t ao_k_pa_accel; /* 16.16 fixed point */
43 uint32_t ao_pa; /* integer portion */
44 int16_t ao_pa_speed; /* integer portion */
45 int16_t ao_pa_accel; /* integer portion */
48 ao_microkalman_init(void)
55 ao_microkalman_predict(void)
57 ao_k_pa += fix16_to_fix8((int32_t) ao_pa_speed * AO_MK_STEP + (int32_t) ao_pa_accel * AO_MK_STEP_2_2);
58 ao_k_pa_speed += (int32_t) ao_pa_accel * AO_MK_STEP;
62 ao_microkalman_correct(void)
64 int16_t e; /* Height error in Pa */
66 e = pa - from_fix8(ao_k_pa);
68 ao_k_pa += fix16_to_fix8((int32_t) e * AO_MK_BARO_K0_10);
69 ao_k_pa_speed += (int32_t) e * AO_MK_BARO_K1_10;
70 ao_k_pa_accel += (int32_t) e * AO_MK_BARO_K2_10;
71 ao_pa = from_fix8(ao_k_pa);
72 ao_pa_speed = from_fix(ao_k_pa_speed);
73 ao_pa_accel = from_fix(ao_k_pa_accel);