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