diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/Makefile.proto | 6 | ||||
| -rw-r--r-- | src/ao.h | 131 | ||||
| -rw-r--r-- | src/ao_adc.c | 2 | ||||
| -rw-r--r-- | src/ao_config.c | 6 | ||||
| -rw-r--r-- | src/ao_flight.c | 452 | ||||
| -rw-r--r-- | src/ao_flight_test.c | 43 | ||||
| -rw-r--r-- | src/ao_kalman.c | 245 | ||||
| -rw-r--r-- | src/ao_log_big.c | 8 | ||||
| -rw-r--r-- | src/ao_sample.c | 206 | ||||
| -rw-r--r-- | src/ao_stdio.c | 2 |
10 files changed, 635 insertions, 466 deletions
diff --git a/src/Makefile.proto b/src/Makefile.proto index 85c0c46e..8dd21a64 100644 --- a/src/Makefile.proto +++ b/src/Makefile.proto @@ -147,6 +147,8 @@ SKY_DRIVER_SRC = \ # TM_TASK_SRC = \ ao_flight.c \ + ao_sample.c \ + ao_kalman.c \ ao_log.c \ ao_log_big.c \ ao_report.c \ @@ -179,6 +181,8 @@ TMINI_DRIVER_SRC = \ TMINI_TASK_SRC = \ ao_flight.c \ + ao_sample.c \ + ao_kalman.c \ ao_log.c \ ao_log_tiny.c \ ao_report.c \ @@ -207,6 +211,8 @@ TNANO_DRIVER_SRC = \ TNANO_TASK_SRC = \ ao_flight.c \ + ao_sample.c \ + ao_kalman.c \ ao_log.c \ ao_log_tiny.c \ ao_report.c \ @@ -695,22 +695,10 @@ enum ao_flight_state { ao_flight_invalid = 9 }; -extern __data uint8_t ao_flight_adc; extern __pdata enum ao_flight_state ao_flight_state; -extern __pdata uint16_t ao_flight_tick; -extern __xdata int16_t ao_ground_pres; -extern __pdata int16_t ao_ground_accel; + extern __pdata uint16_t ao_launch_time; extern __xdata uint8_t ao_flight_force_idle; -extern __pdata int16_t ao_ground_height; -extern __pdata int16_t ao_max_height; -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 */ - -#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)) /* Flight thread */ void @@ -721,6 +709,121 @@ void ao_flight_init(void); /* + * 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 + */ + +#define GRAVITY 9.80665 + +/* + * Above this height, the baro sensor doesn't work + */ +#define AO_MAX_BARO_HEIGHT 12000 + +/* + * 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 __pdata int16_t ao_sample_pres; /* most recent pressure sensor reading */ +extern __pdata int16_t ao_sample_alt; /* MSL of ao_sample_pres */ +extern __pdata int16_t ao_sample_height; /* AGL of ao_sample_pres */ +extern __data uint8_t ao_sample_adc; /* Ring position of last processed sample */ + +#if HAS_ACCEL +extern __pdata int16_t ao_sample_accel; /* most recent accel sensor reading */ +#endif + +extern __xdata int16_t ao_ground_pres; /* startup pressure */ +extern __xdata int16_t ao_ground_height; /* MSL of ao_ground_pres */ + +#if HAS_ACCEL +extern __xdata int16_t ao_ground_accel; /* startup acceleration */ +extern __xdata int16_t ao_accel_2g; /* factory accel calibration */ +extern __xdata int32_t ao_accel_scale; /* sensor to m/s² conversion */ +#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 __pdata int16_t ao_max_height; /* max of ao_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); + +/* * ao_report.c */ @@ -1054,7 +1157,7 @@ extern __xdata uint8_t ao_stdin_ready; void ao_add_stdio(char (*pollchar)(void), void (*putchar)(char) __reentrant, - void (*flush)(void)); + void (*flush)(void)) __reentrant; /* * ao_ignite.c diff --git a/src/ao_adc.c b/src/ao_adc.c index d77e7753..48568383 100644 --- a/src/ao_adc.c +++ b/src/ao_adc.c @@ -41,7 +41,7 @@ ao_adc_poll(void) void ao_adc_get(__xdata struct ao_adc *packet) { - uint8_t i = ao_adc_ring_prev(ao_flight_adc); + uint8_t i = ao_adc_ring_prev(ao_sample_adc); memcpy(packet, &ao_adc_ring[i], sizeof (struct ao_adc)); } diff --git a/src/ao_config.c b/src/ao_config.c index 771b21a1..319febb9 100644 --- a/src/ao_config.c +++ b/src/ao_config.c @@ -215,10 +215,10 @@ ao_config_accel_calibrate_auto(char *orientation) __reentrant puts("Calibrating..."); flush(); i = ACCEL_CALIBRATE_SAMPLES; accel_total = 0; - cal_adc_ring = ao_flight_adc; + cal_adc_ring = ao_sample_adc; while (i) { - ao_sleep(DATA_TO_XDATA(&ao_flight_adc)); - while (i && cal_adc_ring != ao_flight_adc) { + ao_sleep(DATA_TO_XDATA(&ao_sample_adc)); + while (i && cal_adc_ring != ao_sample_adc) { accel_total += (int32_t) ao_adc_ring[cal_adc_ring].accel; cal_adc_ring = ao_adc_ring_next(cal_adc_ring); i--; diff --git a/src/ao_flight.c b/src/ao_flight.c index 88f0544f..94fbf178 100644 --- a/src/ao_flight.c +++ b/src/ao_flight.c @@ -34,13 +34,7 @@ /* Main flight thread. */ __pdata enum ao_flight_state ao_flight_state; /* current flight state */ -__pdata uint16_t ao_flight_tick; /* time of last data */ -__pdata uint16_t ao_flight_prev_tick; /* time of previous data */ -__xdata int16_t ao_ground_pres; /* startup pressure */ __pdata uint16_t ao_launch_tick; /* time of launch detect */ -#if HAS_ACCEL -__pdata int16_t ao_ground_accel; /* startup acceleration */ -#endif /* * track min/max data over a long interval to detect @@ -50,59 +44,7 @@ __pdata uint16_t ao_interval_end; __pdata int16_t ao_interval_min_height; __pdata int16_t ao_interval_max_height; -__data uint8_t ao_flight_adc; -__pdata int16_t ao_raw_pres; -__xdata uint8_t ao_flight_force_idle; - -#if HAS_ACCEL -__pdata int16_t ao_raw_accel, ao_raw_accel_prev; -__pdata int16_t ao_accel_2g; - -/* 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 - */ - -#define GRAVITY 9.80665 - -#define ACCEL_NOSE_UP (ao_accel_2g >> 2) - -#endif - -/* - * 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 - */ +__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 @@ -110,228 +52,6 @@ __pdata int16_t ao_accel_2g; #define BOOST_TICKS_MAX AO_SEC_TO_TICKS(15) -#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) - -#include "ao_kalman.h" - -__pdata int16_t ao_ground_height; -__pdata int16_t ao_height; -__pdata int16_t ao_speed; -__pdata int16_t ao_accel; -__pdata int16_t ao_max_height; - -static __pdata int32_t ao_k_height; -static __pdata int32_t ao_k_speed; -static __pdata int32_t ao_k_accel; - -#define AO_K_STEP_100 to_fix16(0.01) -#define AO_K_STEP_2_2_100 to_fix16(0.00005) - -#define AO_K_STEP_10 to_fix16(0.1) -#define AO_K_STEP_2_2_10 to_fix16(0.005) - -/* - * Above this height, the baro sensor doesn't work - */ -#define AO_MAX_BARO_HEIGHT 12000 - -/* - * Above this speed, baro measurements are unreliable - */ -#define AO_MAX_BARO_SPEED 200 - -static void -ao_kalman_predict(void) -{ -#ifdef AO_FLIGHT_TEST - if (ao_flight_tick - ao_flight_prev_tick > 5) { - ao_k_height += ((int32_t) ao_speed * AO_K_STEP_10 + - (int32_t) ao_accel * AO_K_STEP_2_2_10) >> 4; - ao_k_speed += (int32_t) ao_accel * AO_K_STEP_10; - - return; - } - if (ao_flight_debug) { - printf ("predict speed %g + (%g * %g) = %g\n", - ao_k_speed / (65536.0 * 16.0), ao_accel / 16.0, AO_K_STEP_100 / 65536.0, - (ao_k_speed + (int32_t) ao_accel * AO_K_STEP_100) / (65536.0 * 16.0)); - } -#endif - ao_k_height += ((int32_t) ao_speed * AO_K_STEP_100 + - (int32_t) ao_accel * AO_K_STEP_2_2_100) >> 4; - ao_k_speed += (int32_t) ao_accel * AO_K_STEP_100; -} - -static __pdata int16_t ao_error_h; -static __pdata int16_t ao_raw_alt; -static __pdata int16_t ao_raw_height; -static __pdata int16_t ao_error_h_sq_avg; - -static void -ao_kalman_err_height(void) -{ - int16_t e; - int16_t height_distrust; -#if HAS_ACCEL - int16_t speed_distrust; -#endif - - ao_error_h = ao_raw_height - (int16_t) (ao_k_height >> 16); - - e = ao_error_h; - if (e < 0) - e = -e; - if (e > 127) - e = 127; -#if HAS_ACCEL - ao_error_h_sq_avg -= ao_error_h_sq_avg >> 2; - ao_error_h_sq_avg += (e * e) >> 2; -#else - ao_error_h_sq_avg -= ao_error_h_sq_avg >> 4; - ao_error_h_sq_avg += (e * e) >> 4; -#endif - - height_distrust = ao_raw_height - AO_MAX_BARO_HEIGHT; -#if HAS_ACCEL - /* speed is stored * 16, but we need to ramp between 200 and 328, so - * we want to multiply by 2. The result is a shift by 3. - */ - speed_distrust = (ao_speed - AO_MS_TO_SPEED(AO_MAX_BARO_SPEED)) >> (4 - 1); - if (speed_distrust <= 0) - speed_distrust = 0; - else if (speed_distrust > height_distrust) - height_distrust = speed_distrust; -#endif - if (height_distrust <= 0) - height_distrust = 0; - - if (height_distrust) { -#ifdef AO_FLIGHT_TEST - int old_ao_error_h = ao_error_h; -#endif - if (height_distrust > 0x100) - height_distrust = 0x100; - ao_error_h = (int16_t) (((int32_t) ao_error_h * (0x100 - height_distrust)) >> 8); -#ifdef AO_FLIGHT_TEST - if (ao_flight_debug) { - printf("over height %g over speed %g distrust: %g height: error %d -> %d\n", - (double) (ao_raw_height - AO_MAX_BARO_HEIGHT), - (ao_speed - AO_MS_TO_SPEED(AO_MAX_BARO_SPEED)) / 16.0, - height_distrust / 256.0, - old_ao_error_h, ao_error_h); - } -#endif - } -} - -static void -ao_kalman_correct_baro(void) -{ - ao_kalman_err_height(); -#ifdef AO_FLIGHT_TEST - if (ao_flight_tick - ao_flight_prev_tick > 5) { - ao_k_height += (int32_t) AO_BARO_K0_10 * ao_error_h; - ao_k_speed += (int32_t) AO_BARO_K1_10 * ao_error_h; - ao_k_accel += (int32_t) AO_BARO_K2_10 * ao_error_h; - return; - } -#endif - ao_k_height += (int32_t) AO_BARO_K0_100 * ao_error_h; - ao_k_speed += (int32_t) AO_BARO_K1_100 * ao_error_h; - ao_k_accel += (int32_t) AO_BARO_K2_100 * ao_error_h; -} - -#if HAS_ACCEL -static __pdata int16_t ao_error_a; -static __pdata int32_t ao_accel_scale; - -static void -ao_kalman_err_accel(void) -{ - int32_t accel; - - accel = (ao_ground_accel - ao_raw_accel) * ao_accel_scale; - - /* Can't use ao_accel here as it is the pre-prediction value still */ - ao_error_a = (accel - ao_k_accel) >> 16; -} - -static void -ao_kalman_correct_both(void) -{ - ao_kalman_err_height(); - ao_kalman_err_accel(); - -#ifdef AO_FLIGHT_TEST - if (ao_flight_tick - ao_flight_prev_tick > 5) { - if (ao_flight_debug) { - printf ("correct speed %g + (%g * %g) + (%g * %g) = %g\n", - ao_k_speed / (65536.0 * 16.0), - (double) ao_error_h, AO_BOTH_K10_10 / 65536.0, - (double) ao_error_a, AO_BOTH_K11_10 / 65536.0, - (ao_k_speed + - (int32_t) AO_BOTH_K10_10 * ao_error_h + - (int32_t) AO_BOTH_K11_10 * ao_error_a) / (65536.0 * 16.0)); - } - ao_k_height += - (int32_t) AO_BOTH_K00_10 * ao_error_h + - (int32_t) AO_BOTH_K01_10 * ao_error_a; - ao_k_speed += - (int32_t) AO_BOTH_K10_10 * ao_error_h + - (int32_t) AO_BOTH_K11_10 * ao_error_a; - ao_k_accel += - (int32_t) AO_BOTH_K20_10 * ao_error_h + - (int32_t) AO_BOTH_K21_10 * ao_error_a; - return; - } - if (ao_flight_debug) { - printf ("correct speed %g + (%g * %g) + (%g * %g) = %g\n", - ao_k_speed / (65536.0 * 16.0), - (double) ao_error_h, AO_BOTH_K10_100 / 65536.0, - (double) ao_error_a, AO_BOTH_K11_100 / 65536.0, - (ao_k_speed + - (int32_t) AO_BOTH_K10_100 * ao_error_h + - (int32_t) AO_BOTH_K11_100 * ao_error_a) / (65536.0 * 16.0)); - } -#endif - ao_k_height += - (int32_t) AO_BOTH_K00_100 * ao_error_h + - (int32_t) AO_BOTH_K01_100 * ao_error_a; - ao_k_speed += - (int32_t) AO_BOTH_K10_100 * ao_error_h + - (int32_t) AO_BOTH_K11_100 * ao_error_a; - ao_k_accel += - (int32_t) AO_BOTH_K20_100 * ao_error_h + - (int32_t) AO_BOTH_K21_100 * ao_error_a; -} - -#ifdef FORCE_ACCEL -static void -ao_kalman_correct_accel(void) -{ - ao_kalman_err_accel(); - - if (ao_flight_tick - ao_flight_prev_tick > 5) { - ao_k_height +=(int32_t) AO_ACCEL_K0_10 * ao_error_a; - ao_k_speed += (int32_t) AO_ACCEL_K1_10 * ao_error_a; - ao_k_accel += (int32_t) AO_ACCEL_K2_10 * ao_error_a; - return; - } - ao_k_height += (int32_t) AO_ACCEL_K0_100 * ao_error_a; - ao_k_speed += (int32_t) AO_ACCEL_K1_100 * ao_error_a; - ao_k_accel += (int32_t) AO_ACCEL_K2_100 * ao_error_a; -} -#endif -#endif /* HAS_ACCEL */ - -__xdata int32_t ao_raw_pres_sum; - -#ifdef HAS_ACCEL -__xdata int32_t ao_raw_accel_sum; -#endif - /* Landing is detected by getting constant readings from both pressure and accelerometer * for a fairly long time (AO_INTERVAL_TICKS) */ @@ -342,162 +62,20 @@ __xdata int32_t ao_raw_accel_sum; void ao_flight(void) { - __pdata static uint16_t nsamples = 0; - - ao_flight_adc = ao_adc_head; - ao_raw_pres = 0; -#if HAS_ACCEL - ao_raw_accel_prev = 0; - ao_raw_accel = 0; -#endif - ao_flight_tick = 0; + ao_sample_init(); + ao_flight_state = ao_flight_startup; for (;;) { - ao_wakeup(DATA_TO_XDATA(&ao_flight_adc)); - ao_sleep(DATA_TO_XDATA(&ao_adc_head)); - while (ao_flight_adc != ao_adc_head) { - __xdata struct ao_adc *ao_adc; - ao_flight_prev_tick = ao_flight_tick; - - /* Capture a sample */ - ao_adc = &ao_adc_ring[ao_flight_adc]; - ao_flight_tick = ao_adc->tick; - ao_raw_pres = ao_adc->pres; - ao_raw_alt = ao_pres_to_altitude(ao_raw_pres); - ao_raw_height = ao_raw_alt - ao_ground_height; -#if HAS_ACCEL - ao_raw_accel = ao_adc->accel; -#if HAS_ACCEL_REF - /* - * Ok, the math here is a bit tricky. - * - * ao_raw_accel: ADC output for acceleration - * ao_accel_ref: ADC output for the 5V reference. - * ao_cook_accel: Corrected acceleration value - * Vcc: 3.3V supply to the CC1111 - * Vac: 5V supply to the accelerometer - * accel: input voltage to accelerometer ADC pin - * ref: input voltage to 5V reference ADC pin - * - * - * Measured acceleration is ratiometric to Vcc: - * - * ao_raw_accel accel - * ------------ = ----- - * 32767 Vcc - * - * Measured 5v reference is also ratiometric to Vcc: - * - * ao_accel_ref ref - * ------------ = ----- - * 32767 Vcc - * - * - * ao_accel_ref = 32767 * (ref / Vcc) - * - * Acceleration is measured ratiometric to the 5V supply, - * so what we want is: - * - * ao_cook_accel accel - * ------------- = ----- - * 32767 ref - * - * - * accel Vcc - * = ----- * --- - * Vcc ref - * - * ao_raw_accel 32767 - * = ------------ * ------------ - * 32737 ao_accel_ref - * - * Multiply through by 32767: - * - * ao_raw_accel * 32767 - * ao_cook_accel = -------------------- - * ao_accel_ref - * - * Now, the tricky part. Getting this to compile efficiently - * and keeping all of the values in-range. - * - * First off, we need to use a shift of 16 instead of * 32767 as SDCC - * does the obvious optimizations for byte-granularity shifts: - * - * ao_cook_accel = (ao_raw_accel << 16) / ao_accel_ref - * - * Next, lets check our input ranges: - * - * 0 <= ao_raw_accel <= 0x7fff (singled ended ADC conversion) - * 0x7000 <= ao_accel_ref <= 0x7fff (the 5V ref value is close to 0x7fff) - * - * Plugging in our input ranges, we get an output range of 0 - 0x12490, - * which is 17 bits. That won't work. If we take the accel ref and shift - * by a bit, we'll change its range: - * - * 0xe000 <= ao_accel_ref<<1 <= 0xfffe - * - * ao_cook_accel = (ao_raw_accel << 16) / (ao_accel_ref << 1) - * - * Now the output range is 0 - 0x9248, which nicely fits in 16 bits. It - * is, however, one bit too large for our signed computations. So, we - * take the result and shift that by a bit: - * - * ao_cook_accel = ((ao_raw_accel << 16) / (ao_accel_ref << 1)) >> 1 - * - * This finally creates an output range of 0 - 0x4924. As the ADC only - * provides 11 bits of data, we haven't actually lost any precision, - * just dropped a bit of noise off the low end. - */ - ao_raw_accel = (uint16_t) ((((uint32_t) ao_raw_accel << 16) / (ao_accel_ref[ao_flight_adc] << 1))) >> 1; - ao_adc->accel = ao_raw_accel; -#endif -#endif - if (ao_flight_state > ao_flight_idle) { - ao_kalman_predict(); -#if HAS_ACCEL - if (ao_flight_state <= ao_flight_coast) { -#ifdef FORCE_ACCEL - ao_kalman_correct_accel(); -#else - ao_kalman_correct_both(); -#endif - } else -#endif - ao_kalman_correct_baro(); - ao_height = from_fix(ao_k_height); - ao_speed = from_fix(ao_k_speed); - ao_accel = from_fix(ao_k_accel); - if (ao_height > ao_max_height) - ao_max_height = ao_height; - } - ao_flight_adc = ao_adc_ring_next(ao_flight_adc); - } + /* + * Process ADC samples, just looping + * until the sensors are calibrated. + */ + if (!ao_sample()) + continue; switch (ao_flight_state) { case ao_flight_startup: - /* 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_raw_accel_sum += ao_raw_accel; -#endif - ao_raw_pres_sum += ao_raw_pres; - ++nsamples; - continue; - } - ao_config_get(); -#if HAS_ACCEL - ao_ground_accel = ao_raw_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_raw_pres_sum >> 9; - ao_ground_height = ao_pres_to_altitude(ao_ground_pres); - /* Check to see what mode we should go to. * - Invalid mode if accel cal appears to be out * - pad mode if we're upright, @@ -574,7 +152,7 @@ ao_flight(void) ) { ao_flight_state = ao_flight_boost; - ao_launch_tick = ao_flight_tick; + ao_launch_tick = ao_sample_tick; /* start logging data */ ao_log_start(); @@ -608,7 +186,7 @@ ao_flight(void) * (15 seconds) has past. */ if ((ao_accel < AO_MSS_TO_ACCEL(-2.5) && ao_height > AO_M_TO_HEIGHT(100)) || - (int16_t) (ao_flight_tick - ao_launch_tick) > BOOST_TICKS_MAX) + (int16_t) (ao_sample_tick - ao_launch_tick) > BOOST_TICKS_MAX) { #if HAS_ACCEL ao_flight_state = ao_flight_fast; @@ -646,7 +224,7 @@ ao_flight(void) */ if (ao_speed < 0 #if !HAS_ACCEL - && (ao_raw_alt >= AO_MAX_BARO_HEIGHT || ao_error_h_sq_avg < 100) + && (ao_sample_alt >= AO_MAX_BARO_HEIGHT || ao_error_h_sq_avg < 100) #endif ) { @@ -662,7 +240,7 @@ ao_flight(void) */ /* initialize interval values */ - ao_interval_end = ao_flight_tick + AO_INTERVAL_TICKS; + ao_interval_end = ao_sample_tick + AO_INTERVAL_TICKS; ao_interval_min_height = ao_interval_max_height = ao_height; @@ -706,7 +284,7 @@ ao_flight(void) if (ao_height > ao_interval_max_height) ao_interval_max_height = ao_height; - if ((int16_t) (ao_flight_tick - ao_interval_end) >= 0) { + 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)) { @@ -720,7 +298,7 @@ ao_flight(void) ao_wakeup(DATA_TO_XDATA(&ao_flight_state)); } ao_interval_min_height = ao_interval_max_height = ao_height; - ao_interval_end = ao_flight_tick + AO_INTERVAL_TICKS; + ao_interval_end = ao_sample_tick + AO_INTERVAL_TICKS; } break; case ao_flight_landed: diff --git a/src/ao_flight_test.c b/src/ao_flight_test.c index 91aa0f73..f41acbca 100644 --- a/src/ao_flight_test.c +++ b/src/ao_flight_test.c @@ -53,6 +53,22 @@ struct ao_adc { #define __code #define __reentrant +#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) + +/* + * Above this height, the baro sensor doesn't work + */ +#define AO_MAX_BARO_HEIGHT 12000 + +/* + * Above this speed, baro measurements are unreliable + */ +#define AO_MAX_BARO_SPEED 200 + +#define ACCEL_NOSE_UP (ao_accel_2g >> 2) + enum ao_flight_state { ao_flight_startup = 0, ao_flight_idle = 1, @@ -66,6 +82,11 @@ enum ao_flight_state { ao_flight_invalid = 9 }; +extern enum ao_flight_state ao_flight_state; + +#define FALSE 0 +#define TRUE 1 + struct ao_adc ao_adc_ring[AO_ADC_RING]; uint8_t ao_adc_head; int ao_summary = 0; @@ -171,15 +192,25 @@ struct ao_config ao_config; #define HAS_ACCEL_REF 0 #endif -#include "ao_flight.c" - -#define to_double(f) ((f) / 65536.0) - #define GRAVITY 9.80665 -extern int16_t ao_ground_accel, ao_raw_accel; +extern int16_t ao_ground_accel, ao_flight_accel; extern int16_t ao_accel_2g; +extern uint16_t ao_sample_tick; + +extern int16_t ao_sample_height; +extern int16_t ao_sample_accel; +extern int32_t ao_accel_scale; + +int ao_sample_prev_tick; uint16_t prev_tick; + +#include "ao_kalman.c" +#include "ao_sample.c" +#include "ao_flight.c" + +#define to_double(f) ((f) / 65536.0) + static int ao_records_read = 0; static int ao_eof_read = 0; static int ao_flight_ground_accel; @@ -224,7 +255,7 @@ ao_insert(void) ao_adc_ring[ao_adc_head] = ao_adc_static; ao_adc_head = ao_adc_ring_next(ao_adc_head); if (ao_flight_state != ao_flight_startup) { - double height = ao_pres_to_altitude(ao_raw_pres) - ao_ground_height; + double height = ao_pres_to_altitude(ao_sample_pres) - ao_ground_height; double accel = ((ao_flight_ground_accel - ao_adc_static.accel) * GRAVITY * 2.0) / (ao_config.accel_minus_g - ao_config.accel_plus_g); diff --git a/src/ao_kalman.c b/src/ao_kalman.c new file mode 100644 index 00000000..ee99f375 --- /dev/null +++ b/src/ao_kalman.c @@ -0,0 +1,245 @@ +/* + * 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" +#endif + +#include "ao_kalman.h" + +static __pdata int32_t ao_k_height; +static __pdata int32_t ao_k_speed; +static __pdata int32_t ao_k_accel; + +#define AO_K_STEP_100 to_fix16(0.01) +#define AO_K_STEP_2_2_100 to_fix16(0.00005) + +#define AO_K_STEP_10 to_fix16(0.1) +#define AO_K_STEP_2_2_10 to_fix16(0.005) + +__pdata int16_t ao_height; +__pdata int16_t ao_speed; +__pdata int16_t ao_accel; +__pdata int16_t ao_max_height; + +__pdata int16_t ao_error_h; +__pdata int16_t ao_error_h_sq_avg; + +#if HAS_ACCEL +__pdata int16_t ao_error_a; +#endif + +static void +ao_kalman_predict(void) +{ +#ifdef AO_FLIGHT_TEST + if (ao_sample_tick - ao_sample_prev_tick > 5) { + ao_k_height += ((int32_t) ao_speed * AO_K_STEP_10 + + (int32_t) ao_accel * AO_K_STEP_2_2_10) >> 4; + ao_k_speed += (int32_t) ao_accel * AO_K_STEP_10; + + return; + } + if (ao_flight_debug) { + printf ("predict speed %g + (%g * %g) = %g\n", + ao_k_speed / (65536.0 * 16.0), ao_accel / 16.0, AO_K_STEP_100 / 65536.0, + (ao_k_speed + (int32_t) ao_accel * AO_K_STEP_100) / (65536.0 * 16.0)); + } +#endif + ao_k_height += ((int32_t) ao_speed * AO_K_STEP_100 + + (int32_t) ao_accel * AO_K_STEP_2_2_100) >> 4; + ao_k_speed += (int32_t) ao_accel * AO_K_STEP_100; +} + +static void +ao_kalman_err_height(void) +{ + int16_t e; + int16_t height_distrust; +#if HAS_ACCEL + int16_t speed_distrust; +#endif + + ao_error_h = ao_sample_height - (int16_t) (ao_k_height >> 16); + + e = ao_error_h; + if (e < 0) + e = -e; + if (e > 127) + e = 127; +#if HAS_ACCEL + ao_error_h_sq_avg -= ao_error_h_sq_avg >> 2; + ao_error_h_sq_avg += (e * e) >> 2; +#else + ao_error_h_sq_avg -= ao_error_h_sq_avg >> 4; + ao_error_h_sq_avg += (e * e) >> 4; +#endif + + height_distrust = ao_sample_height - AO_MAX_BARO_HEIGHT; +#if HAS_ACCEL + /* speed is stored * 16, but we need to ramp between 200 and 328, so + * we want to multiply by 2. The result is a shift by 3. + */ + speed_distrust = (ao_speed - AO_MS_TO_SPEED(AO_MAX_BARO_SPEED)) >> (4 - 1); + if (speed_distrust <= 0) + speed_distrust = 0; + else if (speed_distrust > height_distrust) + height_distrust = speed_distrust; +#endif + if (height_distrust <= 0) + height_distrust = 0; + + if (height_distrust) { +#ifdef AO_FLIGHT_TEST + int old_ao_error_h = ao_error_h; +#endif + if (height_distrust > 0x100) + height_distrust = 0x100; + ao_error_h = (int16_t) (((int32_t) ao_error_h * (0x100 - height_distrust)) >> 8); +#ifdef AO_FLIGHT_TEST + if (ao_flight_debug) { + printf("over height %g over speed %g distrust: %g height: error %d -> %d\n", + (double) (ao_sample_height - AO_MAX_BARO_HEIGHT), + (ao_speed - AO_MS_TO_SPEED(AO_MAX_BARO_SPEED)) / 16.0, + height_distrust / 256.0, + old_ao_error_h, ao_error_h); + } +#endif + } +} + +static void +ao_kalman_correct_baro(void) +{ + ao_kalman_err_height(); +#ifdef AO_FLIGHT_TEST + if (ao_sample_tick - ao_sample_prev_tick > 5) { + ao_k_height += (int32_t) AO_BARO_K0_10 * ao_error_h; + ao_k_speed += (int32_t) AO_BARO_K1_10 * ao_error_h; + ao_k_accel += (int32_t) AO_BARO_K2_10 * ao_error_h; + return; + } +#endif + ao_k_height += (int32_t) AO_BARO_K0_100 * ao_error_h; + ao_k_speed += (int32_t) AO_BARO_K1_100 * ao_error_h; + ao_k_accel += (int32_t) AO_BARO_K2_100 * ao_error_h; +} + +#if HAS_ACCEL + +static void +ao_kalman_err_accel(void) +{ + int32_t accel; + + accel = (ao_ground_accel - ao_sample_accel) * ao_accel_scale; + + /* Can't use ao_accel here as it is the pre-prediction value still */ + ao_error_a = (accel - ao_k_accel) >> 16; +} + +static void +ao_kalman_correct_both(void) +{ + ao_kalman_err_height(); + ao_kalman_err_accel(); + +#ifdef AO_FLIGHT_TEST + if (ao_sample_tick - ao_sample_prev_tick > 5) { + if (ao_flight_debug) { + printf ("correct speed %g + (%g * %g) + (%g * %g) = %g\n", + ao_k_speed / (65536.0 * 16.0), + (double) ao_error_h, AO_BOTH_K10_10 / 65536.0, + (double) ao_error_a, AO_BOTH_K11_10 / 65536.0, + (ao_k_speed + + (int32_t) AO_BOTH_K10_10 * ao_error_h + + (int32_t) AO_BOTH_K11_10 * ao_error_a) / (65536.0 * 16.0)); + } + ao_k_height += + (int32_t) AO_BOTH_K00_10 * ao_error_h + + (int32_t) AO_BOTH_K01_10 * ao_error_a; + ao_k_speed += + (int32_t) AO_BOTH_K10_10 * ao_error_h + + (int32_t) AO_BOTH_K11_10 * ao_error_a; + ao_k_accel += + (int32_t) AO_BOTH_K20_10 * ao_error_h + + (int32_t) AO_BOTH_K21_10 * ao_error_a; + return; + } + if (ao_flight_debug) { + printf ("correct speed %g + (%g * %g) + (%g * %g) = %g\n", + ao_k_speed / (65536.0 * 16.0), + (double) ao_error_h, AO_BOTH_K10_100 / 65536.0, + (double) ao_error_a, AO_BOTH_K11_100 / 65536.0, + (ao_k_speed + + (int32_t) AO_BOTH_K10_100 * ao_error_h + + (int32_t) AO_BOTH_K11_100 * ao_error_a) / (65536.0 * 16.0)); + } +#endif + ao_k_height += + (int32_t) AO_BOTH_K00_100 * ao_error_h + + (int32_t) AO_BOTH_K01_100 * ao_error_a; + ao_k_speed += + (int32_t) AO_BOTH_K10_100 * ao_error_h + + (int32_t) AO_BOTH_K11_100 * ao_error_a; + ao_k_accel += + (int32_t) AO_BOTH_K20_100 * ao_error_h + + (int32_t) AO_BOTH_K21_100 * ao_error_a; +} + +#ifdef FORCE_ACCEL +static void +ao_kalman_correct_accel(void) +{ + ao_kalman_err_accel(); + + if (ao_sample_tick - ao_sample_prev_tick > 5) { + ao_k_height +=(int32_t) AO_ACCEL_K0_10 * ao_error_a; + ao_k_speed += (int32_t) AO_ACCEL_K1_10 * ao_error_a; + ao_k_accel += (int32_t) AO_ACCEL_K2_10 * ao_error_a; + return; + } + ao_k_height += (int32_t) AO_ACCEL_K0_100 * ao_error_a; + ao_k_speed += (int32_t) AO_ACCEL_K1_100 * ao_error_a; + ao_k_accel += (int32_t) AO_ACCEL_K2_100 * ao_error_a; +} +#endif +#endif /* HAS_ACCEL */ + +void +ao_kalman(void) +{ + ao_kalman_predict(); +#if HAS_ACCEL + if (ao_flight_state <= ao_flight_coast) { +#ifdef FORCE_ACCEL + ao_kalman_correct_accel(); +#else + ao_kalman_correct_both(); +#endif + } else +#endif + ao_kalman_correct_baro(); + ao_height = from_fix(ao_k_height); + ao_speed = from_fix(ao_k_speed); + ao_accel = from_fix(ao_k_accel); + if (ao_height > ao_max_height) + ao_max_height = ao_height; +#ifdef AO_FLIGHT_TEST + ao_sample_prev_tick = ao_sample_tick; +#endif +} diff --git a/src/ao_log_big.c b/src/ao_log_big.c index ab6b02f5..0c6cff85 100644 --- a/src/ao_log_big.c +++ b/src/ao_log_big.c @@ -82,7 +82,7 @@ ao_log(void) ao_sleep(&ao_log_running); log.type = AO_LOG_FLIGHT; - log.tick = ao_flight_tick; + log.tick = ao_sample_tick; #if HAS_ACCEL log.u.flight.ground_accel = ao_ground_accel; #endif @@ -92,12 +92,12 @@ ao_log(void) /* Write the whole contents of the ring to the log * when starting up. */ - ao_log_adc_pos = ao_adc_ring_next(ao_flight_adc); + ao_log_adc_pos = ao_adc_ring_next(ao_sample_adc); next_other = next_sensor = ao_adc_ring[ao_log_adc_pos].tick; ao_log_state = ao_flight_startup; for (;;) { /* Write samples to EEPROM */ - while (ao_log_adc_pos != ao_flight_adc) { + while (ao_log_adc_pos != ao_sample_adc) { log.tick = ao_adc_ring[ao_log_adc_pos].tick; if ((int16_t) (log.tick - next_sensor) >= 0) { log.type = AO_LOG_SENSOR; @@ -126,7 +126,7 @@ ao_log(void) if (ao_flight_state != ao_log_state) { ao_log_state = ao_flight_state; log.type = AO_LOG_STATE; - log.tick = ao_flight_tick; + log.tick = ao_sample_tick; log.u.state.state = ao_log_state; log.u.state.reason = 0; ao_log_data(&log); diff --git a/src/ao_sample.c b/src/ao_sample.c new file mode 100644 index 00000000..ef403393 --- /dev/null +++ b/src/ao_sample.c @@ -0,0 +1,206 @@ +/* + * 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" +#endif + +/* + * Current sensor values + */ + +__pdata uint16_t ao_sample_tick; /* time of last data */ +__pdata int16_t ao_sample_pres; +__pdata int16_t ao_sample_alt; +__pdata int16_t ao_sample_height; +#if HAS_ACCEL +__pdata int16_t ao_sample_accel; +#endif + +__data uint8_t ao_sample_adc; + +/* + * Sensor calibration values + */ + +__xdata int16_t ao_ground_pres; /* startup pressure */ +__xdata int16_t ao_ground_height; /* MSL of ao_ground_pres */ + +#if HAS_ACCEL +__xdata int16_t ao_ground_accel; /* startup acceleration */ +__xdata int16_t ao_accel_2g; /* factory accel calibration */ +__xdata int32_t ao_accel_scale; /* sensor to m/s² conversion */ +#endif + +static __xdata uint8_t ao_preflight; /* in preflight mode */ + +static __xdata uint16_t nsamples; +__xdata int32_t ao_sample_pres_sum; +#if HAS_ACCEL +__xdata 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; + ao_preflight = FALSE; + } + 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 = ao_pres_to_altitude(ao_ground_pres); +} + +uint8_t +ao_sample(void) +{ + ao_wakeup(DATA_TO_XDATA(&ao_sample_adc)); + ao_sleep(DATA_TO_XDATA(&ao_adc_head)); + while (ao_sample_adc != ao_adc_head) { + __xdata struct ao_adc *ao_adc; + + /* Capture a sample */ + ao_adc = &ao_adc_ring[ao_sample_adc]; + ao_sample_tick = ao_adc->tick; + ao_sample_pres = ao_adc->pres; + ao_sample_alt = ao_pres_to_altitude(ao_sample_pres); + ao_sample_height = ao_sample_alt - ao_ground_height; +#if HAS_ACCEL + ao_sample_accel = ao_adc->accel; +#if HAS_ACCEL_REF + /* + * Ok, the math here is a bit tricky. + * + * ao_sample_accel: ADC output for acceleration + * ao_accel_ref: ADC output for the 5V reference. + * ao_cook_accel: Corrected acceleration value + * Vcc: 3.3V supply to the CC1111 + * Vac: 5V supply to the accelerometer + * accel: input voltage to accelerometer ADC pin + * ref: input voltage to 5V reference ADC pin + * + * + * Measured acceleration is ratiometric to Vcc: + * + * ao_sample_accel accel + * ------------ = ----- + * 32767 Vcc + * + * Measured 5v reference is also ratiometric to Vcc: + * + * ao_accel_ref ref + * ------------ = ----- + * 32767 Vcc + * + * + * ao_accel_ref = 32767 * (ref / Vcc) + * + * Acceleration is measured ratiometric to the 5V supply, + * so what we want is: + * + * ao_cook_accel accel + * ------------- = ----- + * 32767 ref + * + * + * accel Vcc + * = ----- * --- + * Vcc ref + * + * ao_sample_accel 32767 + * = ------------ * ------------ + * 32737 ao_accel_ref + * + * Multiply through by 32767: + * + * ao_sample_accel * 32767 + * ao_cook_accel = -------------------- + * ao_accel_ref + * + * Now, the tricky part. Getting this to compile efficiently + * and keeping all of the values in-range. + * + * First off, we need to use a shift of 16 instead of * 32767 as SDCC + * does the obvious optimizations for byte-granularity shifts: + * + * ao_cook_accel = (ao_sample_accel << 16) / ao_accel_ref + * + * Next, lets check our input ranges: + * + * 0 <= ao_sample_accel <= 0x7fff (singled ended ADC conversion) + * 0x7000 <= ao_accel_ref <= 0x7fff (the 5V ref value is close to 0x7fff) + * + * Plugging in our input ranges, we get an output range of 0 - 0x12490, + * which is 17 bits. That won't work. If we take the accel ref and shift + * by a bit, we'll change its range: + * + * 0xe000 <= ao_accel_ref<<1 <= 0xfffe + * + * ao_cook_accel = (ao_sample_accel << 16) / (ao_accel_ref << 1) + * + * Now the output range is 0 - 0x9248, which nicely fits in 16 bits. It + * is, however, one bit too large for our signed computations. So, we + * take the result and shift that by a bit: + * + * ao_cook_accel = ((ao_sample_accel << 16) / (ao_accel_ref << 1)) >> 1 + * + * This finally creates an output range of 0 - 0x4924. As the ADC only + * provides 11 bits of data, we haven't actually lost any precision, + * just dropped a bit of noise off the low end. + */ + ao_sample_accel = (uint16_t) ((((uint32_t) ao_sample_accel << 16) / (ao_accel_ref[ao_sample_adc] << 1))) >> 1; + ao_adc->accel = ao_sample_accel; +#endif +#endif + + if (ao_preflight) + ao_sample_preflight(); + else + ao_kalman(); + ao_sample_adc = ao_adc_ring_next(ao_sample_adc); + } + 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_adc = ao_adc_head; + ao_preflight = TRUE; +} diff --git a/src/ao_stdio.c b/src/ao_stdio.c index 78bbd3c3..6e1f5eff 100644 --- a/src/ao_stdio.c +++ b/src/ao_stdio.c @@ -66,7 +66,7 @@ getchar(void) __reentrant __critical void ao_add_stdio(char (*pollchar)(void), void (*putchar)(char), - void (*flush)(void)) + void (*flush)(void)) __reentrant { if (ao_num_stdios == AO_NUM_STDIOS) ao_panic(AO_PANIC_STDIO); |