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Diffstat (limited to 'src-avr/ao_flight.c')
| -rw-r--r-- | src-avr/ao_flight.c | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/src-avr/ao_flight.c b/src-avr/ao_flight.c new file mode 100644 index 00000000..5460e859 --- /dev/null +++ b/src-avr/ao_flight.c @@ -0,0 +1,318 @@ +/* + * Copyright © 2009 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" +#endif + +#ifndef HAS_ACCEL +#error Please define HAS_ACCEL +#endif + +#ifndef HAS_GPS +#error Please define HAS_GPS +#endif + +#ifndef HAS_USB +#error Please define HAS_USB +#endif + +/* Main flight thread. */ + +__pdata enum ao_flight_state ao_flight_state; /* current flight state */ +__pdata uint16_t ao_launch_tick; /* time of launch detect */ + +/* + * track min/max data over a long interval to detect + * resting + */ +__pdata uint16_t ao_interval_end; +__pdata int16_t ao_interval_min_height; +__pdata int16_t ao_interval_max_height; + +__xdata uint8_t ao_flight_force_idle; + +/* We also have a clock, which can be used to sanity check things in + * case of other failures + */ + +#define BOOST_TICKS_MAX AO_SEC_TO_TICKS(15) + +/* Landing is detected by getting constant readings from both pressure and accelerometer + * for a fairly long time (AO_INTERVAL_TICKS) + */ +#define AO_INTERVAL_TICKS AO_SEC_TO_TICKS(5) + +#define abs(a) ((a) < 0 ? -(a) : (a)) + +void +ao_flight(void) +{ + ao_sample_init(); + ao_flight_state = ao_flight_startup; + for (;;) { + + /* + * Process ADC samples, just looping + * until the sensors are calibrated. + */ + if (!ao_sample()) + continue; + + switch (ao_flight_state) { + case ao_flight_startup: + + /* Check to see what mode we should go to. + * - Invalid mode if accel cal appears to be out + * - pad mode if we're upright, + * - idle mode otherwise + */ +#if HAS_ACCEL + if (ao_config.accel_plus_g == 0 || + ao_config.accel_minus_g == 0 || + ao_ground_accel < ao_config.accel_plus_g - ACCEL_NOSE_UP || + ao_ground_accel > ao_config.accel_minus_g + ACCEL_NOSE_UP) + { + /* Detected an accel value outside -1.5g to 1.5g + * (or uncalibrated values), so we go into invalid mode + */ + ao_flight_state = ao_flight_invalid; + + } else +#endif + if (!ao_flight_force_idle +#if HAS_ACCEL + && ao_ground_accel < ao_config.accel_plus_g + ACCEL_NOSE_UP +#endif + ) + { + /* Set pad mode - we can fly! */ + ao_flight_state = ao_flight_pad; +#if HAS_USB + /* Disable the USB controller in flight mode + * to save power + */ + ao_usb_disable(); +#endif + + /* Disable packet mode in pad state */ + ao_packet_slave_stop(); + + /* Turn on telemetry system */ + ao_rdf_set(1); + ao_telemetry_set_interval(AO_TELEMETRY_INTERVAL_PAD); + + /* signal successful initialization by turning off the LED */ + ao_led_off(AO_LED_RED); + } else { + /* Set idle mode */ + ao_flight_state = ao_flight_idle; + + /* signal successful initialization by turning off the LED */ + ao_led_off(AO_LED_RED); + } + /* wakeup threads due to state change */ + ao_wakeup(DATA_TO_XDATA(&ao_flight_state)); + + break; + case ao_flight_pad: + + /* pad to boost: + * + * barometer: > 20m vertical motion + * OR + * accelerometer: > 2g AND velocity > 5m/s + * + * The accelerometer should always detect motion before + * the barometer, but we use both to make sure this + * transition is detected. If the device + * doesn't have an accelerometer, then ignore the + * speed and acceleration as they are quite noisy + * on the pad. + */ + if (ao_height > AO_M_TO_HEIGHT(20) +#if HAS_ACCEL + || (ao_accel > AO_MSS_TO_ACCEL(20) && + ao_speed > AO_MS_TO_SPEED(5)) +#endif + ) + { + ao_flight_state = ao_flight_boost; + ao_launch_tick = ao_sample_tick; + + /* start logging data */ + ao_log_start(); + + /* Increase telemetry rate */ + ao_telemetry_set_interval(AO_TELEMETRY_INTERVAL_FLIGHT); + + /* disable RDF beacon */ + ao_rdf_set(0); + +#if HAS_GPS + /* Record current GPS position by waking up GPS log tasks */ + ao_wakeup(&ao_gps_data); + ao_wakeup(&ao_gps_tracking_data); +#endif + + ao_wakeup(DATA_TO_XDATA(&ao_flight_state)); + break; + } + break; + case ao_flight_boost: + + /* boost to fast: + * + * accelerometer: start to fall at > 1/4 G + * OR + * time: boost for more than 15 seconds + * + * Detects motor burn out by the switch from acceleration to + * deceleration, or by waiting until the maximum burn duration + * (15 seconds) has past. + */ + if ((ao_accel < AO_MSS_TO_ACCEL(-2.5) && ao_height > AO_M_TO_HEIGHT(100)) || + (int16_t) (ao_sample_tick - ao_launch_tick) > BOOST_TICKS_MAX) + { +#if HAS_ACCEL + ao_flight_state = ao_flight_fast; +#else + ao_flight_state = ao_flight_coast; +#endif + ao_wakeup(DATA_TO_XDATA(&ao_flight_state)); + break; + } + break; +#if HAS_ACCEL + case ao_flight_fast: + /* + * This is essentially the same as coast, + * but the barometer is being ignored as + * it may be unreliable. + */ + if (ao_speed < AO_MS_TO_SPEED(AO_MAX_BARO_SPEED)) + { + ao_flight_state = ao_flight_coast; + ao_wakeup(DATA_TO_XDATA(&ao_flight_state)); + break; + } + break; +#endif + case ao_flight_coast: + + /* apogee detect: coast to drogue deploy: + * + * speed: < 0 + * + * Also make sure the model altitude is tracking + * the measured altitude reasonably closely; otherwise + * we're probably transsonic. + */ + if (ao_speed < 0 +#if !HAS_ACCEL + && (ao_sample_alt >= AO_MAX_BARO_HEIGHT || ao_error_h_sq_avg < 100) +#endif + ) + { + /* ignite the drogue charge */ + ao_ignite(ao_igniter_drogue); + + /* slow down the telemetry system */ + ao_telemetry_set_interval(AO_TELEMETRY_INTERVAL_RECOVER); + + /* Turn the RDF beacon back on */ + ao_rdf_set(1); + + /* + * Start recording min/max height + * to figure out when the rocket has landed + */ + + /* initialize interval values */ + ao_interval_end = ao_sample_tick + AO_INTERVAL_TICKS; + + ao_interval_min_height = ao_interval_max_height = ao_height; + + /* and enter drogue state */ + ao_flight_state = ao_flight_drogue; + ao_wakeup(DATA_TO_XDATA(&ao_flight_state)); + } + + break; + case ao_flight_drogue: + + /* drogue to main deploy: + * + * barometer: reach main deploy altitude + * + * Would like to use the accelerometer for this test, but + * the orientation of the flight computer is unknown after + * drogue deploy, so we ignore it. Could also detect + * high descent rate using the pressure sensor to + * recognize drogue deploy failure and eject the main + * at that point. Perhaps also use the drogue sense lines + * to notice continutity? + */ + if (ao_height <= ao_config.main_deploy) + { + ao_ignite(ao_igniter_main); + ao_flight_state = ao_flight_main; + ao_wakeup(DATA_TO_XDATA(&ao_flight_state)); + } + + /* fall through... */ + case ao_flight_main: + + /* drogue/main to land: + * + * barometer: altitude stable and within 1000m of the launch altitude + */ + + if (ao_height < ao_interval_min_height) + ao_interval_min_height = ao_height; + if (ao_height > ao_interval_max_height) + ao_interval_max_height = ao_height; + + if ((int16_t) (ao_sample_tick - ao_interval_end) >= 0) { + if (ao_height < AO_M_TO_HEIGHT(1000) && + ao_interval_max_height - ao_interval_min_height < AO_M_TO_HEIGHT(5)) + { + ao_flight_state = ao_flight_landed; + + /* turn off the ADC capture */ + ao_timer_set_adc_interval(0); + + ao_wakeup(DATA_TO_XDATA(&ao_flight_state)); + } + ao_interval_min_height = ao_interval_max_height = ao_height; + ao_interval_end = ao_sample_tick + AO_INTERVAL_TICKS; + } + break; + case ao_flight_landed: + break; + } + } +} + +static __xdata struct ao_task flight_task; + +void +ao_flight_init(void) +{ + ao_flight_state = ao_flight_startup; + ao_add_task(&flight_task, ao_flight, "flight"); +} |