diff options
Diffstat (limited to 'src/core/ao_sample.c')
| -rw-r--r-- | src/core/ao_sample.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/src/core/ao_sample.c b/src/core/ao_sample.c new file mode 100644 index 00000000..ac11eef0 --- /dev/null +++ b/src/core/ao_sample.c @@ -0,0 +1,138 @@ +/* + * 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 + +/* + * 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 + +__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 + +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 + +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) { +#if HAS_ACCEL + ao_sample_accel_sum += ao_sample_accel; +#endif + ao_sample_pres_sum += ao_sample_pres; + ++nsamples; + } else { + ao_config_get(); +#if HAS_ACCEL + ao_ground_accel = ao_sample_accel_sum >> 9; + 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_ground_pres = ao_sample_pres_sum >> 9; + ao_ground_height = pres_to_altitude(ao_ground_pres); + ao_preflight = FALSE; + } +} + + +uint8_t +ao_sample(void) +{ + ao_config_get(); + 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; + + 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; + +#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 (ao_preflight) + ao_sample_preflight(); + else + ao_kalman(); + ao_sample_data = ao_data_ring_next(ao_sample_data); + } + return !ao_preflight; +} + +void +ao_sample_init(void) +{ + nsamples = 0; + ao_sample_pres_sum = 0; + ao_sample_pres = 0; +#if HAS_ACCEL + ao_sample_accel_sum = 0; + ao_sample_accel = 0; +#endif + ao_sample_data = ao_data_head; + ao_preflight = TRUE; +} |