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   1 /*
   2  * Copyright © 2009 Keith Packard <keithp@keithp.com>
   3  *
   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.
   7  *
   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.
  12  *
  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.
  16  */
  17
  18 #ifndef AO_FLIGHT_TEST
  19 #include "ao.h"
  20 #endif
  21
  22 #ifndef HAS_ACCEL
  23 #error Please define HAS_ACCEL
  24 #endif
  25
  26 #ifndef HAS_GPS
  27 #error Please define HAS_GPS
  28 #endif
  29
  30 #ifndef HAS_USB
  31 #error Please define HAS_USB
  32 #endif
  33
  34 /* Main flight thread. */
  35
  36 __pdata enum ao_flight_state    ao_flight_state;        /* current flight state */
  37 __pdata uint16_t                ao_boost_tick;          /* time of launch detect */
  38
  39 /*
  40  * track min/max data over a long interval to detect
  41  * resting
  42  */
  43 static __data uint16_t          ao_interval_end;
  44 static __data int16_t           ao_interval_min_height;
  45 static __data int16_t           ao_interval_max_height;
  46 static __data int16_t           ao_coast_avg_accel;
  47
  48 __pdata uint8_t                 ao_flight_force_idle;
  49
  50 /* We also have a clock, which can be used to sanity check things in
  51  * case of other failures
  52  */
  53
  54 #define BOOST_TICKS_MAX AO_SEC_TO_TICKS(15)
  55
  56 /* Landing is detected by getting constant readings from both pressure and accelerometer
  57  * for a fairly long time (AO_INTERVAL_TICKS)
  58  */
  59 #define AO_INTERVAL_TICKS       AO_SEC_TO_TICKS(10)
  60
  61 #define abs(a)  ((a) < 0 ? -(a) : (a))
  62
  63 void
  64 ao_flight(void)
  65 {
  66         ao_sample_init();
  67         ao_flight_state = ao_flight_startup;
  68         for (;;) {
  69
  70                 /*
  71                  * Process ADC samples, just looping
  72                  * until the sensors are calibrated.
  73                  */
  74                 if (!ao_sample())
  75                         continue;
  76
  77                 switch (ao_flight_state) {
  78                 case ao_flight_startup:
  79
  80                         /* Check to see what mode we should go to.
  81                          *  - Invalid mode if accel cal appears to be out
  82                          *  - pad mode if we're upright,
  83                          *  - idle mode otherwise
  84                          */
  85 #if HAS_ACCEL
  86                         if (ao_config.accel_plus_g == 0 ||
  87                             ao_config.accel_minus_g == 0 ||
  88                             ao_ground_accel < ao_config.accel_plus_g - ACCEL_NOSE_UP ||
  89                             ao_ground_accel > ao_config.accel_minus_g + ACCEL_NOSE_UP)
  90                         {
  91                                 /* Detected an accel value outside -1.5g to 1.5g
  92                                  * (or uncalibrated values), so we go into invalid mode
  93                                  */
  94                                 ao_flight_state = ao_flight_invalid;
  95
  96                                 /* Turn on packet system in invalid mode on TeleMetrum */
  97                                 ao_packet_slave_start();
  98                         } else
  99 #endif
 100                                 if (!ao_flight_force_idle
 101 #if HAS_ACCEL
 102                                     && ao_ground_accel < ao_config.accel_plus_g + ACCEL_NOSE_UP
 103 #endif
 104                                         )
 105                         {
 106                                 /* Set pad mode - we can fly! */
 107                                 ao_flight_state = ao_flight_pad;
 108 #if HAS_USB
 109                                 /* Disable the USB controller in flight mode
 110                                  * to save power
 111                                  */
 112                                 ao_usb_disable();
 113 #endif
 114
 115 #if !HAS_ACCEL
 116                                 /* Disable packet mode in pad state on TeleMini */
 117                                 ao_packet_slave_stop();
 118 #endif
 119
 120                                 /* Turn on telemetry system */
 121                                 ao_rdf_set(1);
 122                                 ao_telemetry_set_interval(AO_TELEMETRY_INTERVAL_PAD);
 123
 124                                 /* signal successful initialization by turning off the LED */
 125                                 ao_led_off(AO_LED_RED);
 126                         } else {
 127                                 /* Set idle mode */
 128                                 ao_flight_state = ao_flight_idle;
 129
 130 #if HAS_ACCEL
 131                                 /* Turn on packet system in idle mode on TeleMetrum */
 132                                 ao_packet_slave_start();
 133 #endif
 134
 135                                 /* signal successful initialization by turning off the LED */
 136                                 ao_led_off(AO_LED_RED);
 137                         }
 138                         /* wakeup threads due to state change */
 139                         ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
 140
 141                         break;
 142                 case ao_flight_pad:
 143
 144                         /* pad to boost:
 145                          *
 146                          * barometer: > 20m vertical motion
 147                          *             OR
 148                          * accelerometer: > 2g AND velocity > 5m/s
 149                          *
 150                          * The accelerometer should always detect motion before
 151                          * the barometer, but we use both to make sure this
 152                          * transition is detected. If the device
 153                          * doesn't have an accelerometer, then ignore the
 154                          * speed and acceleration as they are quite noisy
 155                          * on the pad.
 156                          */
 157                         if (ao_height > AO_M_TO_HEIGHT(20)
 158 #if HAS_ACCEL
 159                             || (ao_accel > AO_MSS_TO_ACCEL(20) &&
 160                                 ao_speed > AO_MS_TO_SPEED(5))
 161 #endif
 162                                 )
 163                         {
 164                                 ao_flight_state = ao_flight_boost;
 165                                 ao_boost_tick = ao_sample_tick;
 166
 167                                 /* start logging data */
 168                                 ao_log_start();
 169
 170                                 /* Increase telemetry rate */
 171                                 ao_telemetry_set_interval(AO_TELEMETRY_INTERVAL_FLIGHT);
 172
 173                                 /* disable RDF beacon */
 174                                 ao_rdf_set(0);
 175
 176 #if HAS_GPS
 177                                 /* Record current GPS position by waking up GPS log tasks */
 178                                 ao_wakeup(&ao_gps_data);
 179                                 ao_wakeup(&ao_gps_tracking_data);
 180 #endif
 181
 182                                 ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
 183                         }
 184                         break;
 185                 case ao_flight_boost:
 186
 187                         /* boost to fast:
 188                          *
 189                          * accelerometer: start to fall at > 1/4 G
 190                          *              OR
 191                          * time: boost for more than 15 seconds
 192                          *
 193                          * Detects motor burn out by the switch from acceleration to
 194                          * deceleration, or by waiting until the maximum burn duration
 195                          * (15 seconds) has past.
 196                          */
 197                         if ((ao_accel < AO_MSS_TO_ACCEL(-2.5) && ao_height > AO_M_TO_HEIGHT(100)) ||
 198                             (int16_t) (ao_sample_tick - ao_boost_tick) > BOOST_TICKS_MAX)
 199                         {
 200 #if HAS_ACCEL
 201                                 ao_flight_state = ao_flight_fast;
 202                                 ao_coast_avg_accel = ao_accel;
 203 #else
 204                                 ao_flight_state = ao_flight_coast;
 205 #endif
 206                                 ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
 207                         }
 208                         break;
 209 #if HAS_ACCEL
 210                 case ao_flight_fast:
 211                         /*
 212                          * This is essentially the same as coast,
 213                          * but the barometer is being ignored as
 214                          * it may be unreliable.
 215                          */
 216                         if (ao_speed < AO_MS_TO_SPEED(AO_MAX_BARO_SPEED))
 217                         {
 218                                 ao_flight_state = ao_flight_coast;
 219                                 ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
 220                         } else
 221                                 goto check_re_boost;
 222                         break;
 223 #endif
 224                 case ao_flight_coast:
 225
 226                         /* apogee detect: coast to drogue deploy:
 227                          *
 228                          * speed: < 0
 229                          *
 230                          * Also make sure the model altitude is tracking
 231                          * the measured altitude reasonably closely; otherwise
 232                          * we're probably transsonic.
 233                          */
 234                         if (ao_speed < 0
 235 #if !HAS_ACCEL
 236                             && (ao_sample_alt >= AO_MAX_BARO_HEIGHT || ao_error_h_sq_avg < 100)
 237 #endif
 238                                 )
 239                         {
 240                                 /* ignite the drogue charge */
 241                                 ao_ignite(ao_igniter_drogue);
 242
 243                                 /* slow down the telemetry system */
 244                                 ao_telemetry_set_interval(AO_TELEMETRY_INTERVAL_RECOVER);
 245
 246                                 /* Turn the RDF beacon back on */
 247                                 ao_rdf_set(1);
 248
 249                                 /* and enter drogue state */
 250                                 ao_flight_state = ao_flight_drogue;
 251                                 ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
 252                         }
 253 #if HAS_ACCEL
 254                         else {
 255                         check_re_boost:
 256                                 ao_coast_avg_accel = ao_coast_avg_accel - (ao_coast_avg_accel >> 6) + (ao_accel >> 6);
 257                                 if (ao_coast_avg_accel > AO_MSS_TO_ACCEL(20)) {
 258                                         ao_boost_tick = ao_sample_tick;
 259                                         ao_flight_state = ao_flight_boost;
 260                                         ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
 261                                 }
 262                         }
 263 #endif
 264
 265                         break;
 266                 case ao_flight_drogue:
 267
 268                         /* drogue to main deploy:
 269                          *
 270                          * barometer: reach main deploy altitude
 271                          *
 272                          * Would like to use the accelerometer for this test, but
 273                          * the orientation of the flight computer is unknown after
 274                          * drogue deploy, so we ignore it. Could also detect
 275                          * high descent rate using the pressure sensor to
 276                          * recognize drogue deploy failure and eject the main
 277                          * at that point. Perhaps also use the drogue sense lines
 278                          * to notice continutity?
 279                          */
 280                         if (ao_height <= ao_config.main_deploy)
 281                         {
 282                                 ao_ignite(ao_igniter_main);
 283
 284                                 /*
 285                                  * Start recording min/max height
 286                                  * to figure out when the rocket has landed
 287                                  */
 288
 289                                 /* initialize interval values */
 290                                 ao_interval_end = ao_sample_tick + AO_INTERVAL_TICKS;
 291
 292                                 ao_interval_min_height = ao_interval_max_height = ao_avg_height;
 293
 294                                 ao_flight_state = ao_flight_main;
 295                                 ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
 296                         }
 297                         break;
 298
 299                         /* fall through... */
 300                 case ao_flight_main:
 301
 302                         /* main to land:
 303                          *
 304                          * barometer: altitude stable
 305                          */
 306
 307                         if (ao_avg_height < ao_interval_min_height)
 308                                 ao_interval_min_height = ao_avg_height;
 309                         if (ao_avg_height > ao_interval_max_height)
 310                                 ao_interval_max_height = ao_avg_height;
 311
 312                         if ((int16_t) (ao_sample_tick - ao_interval_end) >= 0) {
 313                                 if (ao_interval_max_height - ao_interval_min_height <= AO_M_TO_HEIGHT(4))
 314                                 {
 315                                         ao_flight_state = ao_flight_landed;
 316
 317                                         /* turn off the ADC capture */
 318                                         ao_timer_set_adc_interval(0);
 319
 320                                         ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
 321                                 }
 322                                 ao_interval_min_height = ao_interval_max_height = ao_avg_height;
 323                                 ao_interval_end = ao_sample_tick + AO_INTERVAL_TICKS;
 324                         }
 325                         break;
 326                 case ao_flight_landed:
 327                         break;
 328                 }
 329         }
 330 }
 331
 332 static __xdata struct ao_task   flight_task;
 333
 334 void
 335 ao_flight_init(void)
 336 {
 337         ao_flight_state = ao_flight_startup;
 338         ao_add_task(&flight_task, ao_flight, "flight");
 339 }