X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=blobdiff_plain;f=src%2Fkernel%2Fao_sample.h;fp=src%2Fkernel%2Fao_sample.h;h=16d4c5076774d04ad6adefc70064f1dae43d6626;hp=0000000000000000000000000000000000000000;hb=24167015705ae831692b95735968b04a876f935e;hpb=bb9fdef607728cc326a82aa632e59724f272e53b diff --git a/src/kernel/ao_sample.h b/src/kernel/ao_sample.h new file mode 100644 index 00000000..16d4c507 --- /dev/null +++ b/src/kernel/ao_sample.h @@ -0,0 +1,156 @@ +/* + * Copyright © 2012 Keith Packard + * + * 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_SAMPLE_H_ +#define _AO_SAMPLE_H_ + +#include + +/* + * ao_sample.c + */ + +/* + * Barometer calibration + * + * We directly sample the barometer. The specs say: + * + * Pressure range: 15-115 kPa + * Voltage at 115kPa: 2.82 + * Output scale: 27mV/kPa + * + * If we want to detect launch with the barometer, we need + * a large enough bump to not be fooled by noise. At typical + * launch elevations (0-2000m), a 200Pa pressure change cooresponds + * to about a 20m elevation change. This is 5.4mV, or about 3LSB. + * As all of our calculations are done in 16 bits, we'll actually see a change + * of 16 times this though + * + * 27 mV/kPa * 32767 / 3300 counts/mV = 268.1 counts/kPa + */ + +/* Accelerometer calibration + * + * We're sampling the accelerometer through a resistor divider which + * consists of 5k and 10k resistors. This multiplies the values by 2/3. + * That goes into the cc1111 A/D converter, which is running at 11 bits + * of precision with the bits in the MSB of the 16 bit value. Only positive + * values are used, so values should range from 0-32752 for 0-3.3V. The + * specs say we should see 40mV/g (uncalibrated), multiply by 2/3 for what + * the A/D converter sees (26.67 mV/g). We should see 32752/3300 counts/mV, + * for a final computation of: + * + * 26.67 mV/g * 32767/3300 counts/mV = 264.8 counts/g + * + * Zero g was measured at 16000 (we would expect 16384). + * Note that this value is only require to tell if the + * rocket is standing upright. Once that is determined, + * the value of the accelerometer is averaged for 100 samples + * to find the resting accelerometer value, which is used + * for all further flight computations + */ + +/* + * Above this height, the baro sensor doesn't work + */ +#if HAS_MS5607 +#define AO_MAX_BARO_HEIGHT 30000 +#else +#define AO_MAX_BARO_HEIGHT 12000 +#endif + +/* + * Above this speed, baro measurements are unreliable + */ +#define AO_MAX_BARO_SPEED 200 + +#define ACCEL_NOSE_UP (ao_accel_2g >> 2) + +/* + * Speed and acceleration are scaled by 16 to provide a bit more + * resolution while still having reasonable range. Note that this + * limits speed to 2047m/s (around mach 6) and acceleration to + * 2047m/s² (over 200g) + */ + +#define AO_M_TO_HEIGHT(m) ((int16_t) (m)) +#define AO_MS_TO_SPEED(ms) ((int16_t) ((ms) * 16)) +#define AO_MSS_TO_ACCEL(mss) ((int16_t) ((mss) * 16)) + +extern __pdata uint16_t ao_sample_tick; /* time of last data */ +extern __data uint8_t ao_sample_adc; /* Ring position of last processed sample */ +extern __data uint8_t ao_sample_data; /* Ring position of last processed sample */ + +#if HAS_BARO +extern __pdata pres_t ao_sample_pres; /* most recent pressure sensor reading */ +extern __pdata alt_t ao_sample_alt; /* MSL of ao_sample_pres */ +extern __pdata alt_t ao_sample_height; /* AGL of ao_sample_pres */ +extern __pdata pres_t ao_ground_pres; /* startup pressure */ +extern __pdata alt_t ao_ground_height; /* MSL of ao_ground_pres */ +#endif + +#if HAS_ACCEL +extern __pdata accel_t ao_sample_accel; /* most recent accel sensor reading */ +extern __pdata accel_t ao_ground_accel; /* startup acceleration */ +extern __pdata accel_t ao_accel_2g; /* factory accel calibration */ +extern __pdata int32_t ao_accel_scale; /* sensor to m/s² conversion */ +#endif +#if HAS_GYRO +extern __pdata accel_t ao_ground_accel_along; +extern __pdata accel_t ao_ground_accel_across; +extern __pdata accel_t ao_ground_accel_through; +extern __pdata int32_t ao_ground_pitch; /* * 512 */ +extern __pdata int32_t ao_ground_yaw; /* * 512 */ +extern __pdata int32_t ao_ground_roll; /* * 512 */ +extern __pdata accel_t ao_sample_accel_along; +extern __pdata accel_t ao_sample_accel_across; +extern __pdata accel_t ao_sample_accel_through; +extern __pdata gyro_t ao_sample_roll; +extern __pdata gyro_t ao_sample_pitch; +extern __pdata gyro_t ao_sample_yaw; +extern __pdata angle_t ao_sample_orient; +#endif + +void ao_sample_init(void); + +/* returns FALSE in preflight mode, TRUE in flight mode */ +uint8_t ao_sample(void); + +/* + * ao_kalman.c + */ + +#define to_fix16(x) ((int16_t) ((x) * 65536.0 + 0.5)) +#define to_fix32(x) ((int32_t) ((x) * 65536.0 + 0.5)) +#define from_fix(x) ((x) >> 16) + +extern __pdata int16_t ao_height; /* meters */ +extern __pdata int16_t ao_speed; /* m/s * 16 */ +extern __pdata int16_t ao_accel; /* m/s² * 16 */ +extern __xdata int16_t ao_max_height; /* max of ao_height */ +extern __xdata int16_t ao_avg_height; /* running average of height */ + +extern __pdata int16_t ao_error_h; +extern __pdata int16_t ao_error_h_sq_avg; + +#if HAS_ACCEL +extern __pdata int16_t ao_error_a; +#endif + +void ao_kalman(void); + +#endif /* _AO_SAMPLE_H_ */