#ifndef AO_FLIGHT_TEST
#include "ao.h"
+#include <ao_data.h>
+#endif
+
+#if HAS_GYRO
+#include <ao_quaternion.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 int16_t ao_sample_pres;
-__pdata int16_t ao_sample_alt;
-__pdata int16_t ao_sample_height;
+__pdata pres_t ao_sample_pres;
+__pdata alt_t ao_sample_alt;
+__pdata alt_t ao_sample_height;
#if HAS_ACCEL
-__pdata int16_t ao_sample_accel;
+__pdata accel_t ao_sample_accel;
+#endif
+#if HAS_GYRO
+__pdata accel_t ao_sample_accel_along;
+__pdata accel_t ao_sample_accel_across;
+__pdata accel_t ao_sample_accel_through;
+__pdata gyro_t ao_sample_roll;
+__pdata gyro_t ao_sample_pitch;
+__pdata gyro_t ao_sample_yaw;
+__pdata angle_t ao_orient;
#endif
-__data uint8_t ao_sample_adc;
+__data uint8_t ao_sample_data;
/*
* Sensor calibration values
*/
-__pdata int16_t ao_ground_pres; /* startup pressure */
-__pdata int16_t ao_ground_height; /* MSL of ao_ground_pres */
+__pdata pres_t ao_ground_pres; /* startup pressure */
+__pdata alt_t ao_ground_height; /* MSL of ao_ground_pres */
#if HAS_ACCEL
-__pdata int16_t ao_ground_accel; /* startup acceleration */
-__pdata int16_t ao_accel_2g; /* factory accel calibration */
+__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
+#if HAS_GYRO
+__pdata accel_t ao_ground_accel_along;
+__pdata accel_t ao_ground_accel_across;
+__pdata accel_t ao_ground_accel_through;
+__pdata gyro_t ao_ground_pitch;
+__pdata gyro_t ao_ground_yaw;
+__pdata gyro_t ao_ground_roll;
+#endif
+
static __pdata uint8_t ao_preflight; /* in preflight mode */
static __pdata uint16_t nsamples;
#if HAS_ACCEL
__pdata int32_t ao_sample_accel_sum;
#endif
+#if HAS_GYRO
+__pdata int32_t ao_sample_accel_along_sum;
+__pdata int32_t ao_sample_accel_across_sum;
+__pdata int32_t ao_sample_accel_through_sum;
+__pdata int32_t ao_sample_pitch_sum;
+__pdata int32_t ao_sample_yaw_sum;
+__pdata int32_t ao_sample_roll_sum;
+static struct ao_quaternion ao_rotation;
+static struct ao_quaternion ao_pad_orientation;
+#endif
+
+static void
+ao_sample_preflight_add(void)
+{
+#if HAS_ACCEL
+ ao_sample_accel_sum += ao_sample_accel;
+#endif
+ ao_sample_pres_sum += ao_sample_pres;
+#if HAS_GYRO
+ ao_sample_accel_along_sum += ao_sample_accel_along;
+ ao_sample_accel_across_sum += ao_sample_accel_across;
+ ao_sample_accel_through_sum += ao_sample_accel_through;
+ ao_sample_pitch_sum += ao_sample_pitch;
+ ao_sample_yaw_sum += ao_sample_yaw;
+ ao_sample_roll_sum += ao_sample_roll;
+#endif
+ ++nsamples;
+}
+
+static void
+ao_sample_preflight_set(void)
+{
+#if HAS_ACCEL
+ ao_ground_accel = ao_sample_accel_sum >> 9;
+ ao_sample_accel_sum = 0;
+#endif
+ ao_ground_pres = ao_sample_pres_sum >> 9;
+ ao_ground_height = pres_to_altitude(ao_ground_pres);
+ ao_sample_pres_sum = 0;
+#if HAS_GYRO
+ ao_ground_accel_along = ao_sample_accel_along_sum >> 9;
+ ao_ground_accel_across = ao_sample_accel_across_sum >> 9;
+ ao_ground_accel_through = ao_sample_accel_through_sum >> 9;
+ ao_ground_pitch = ao_sample_pitch_sum >> 9;
+ ao_ground_yaw = ao_sample_yaw_sum >> 9;
+ ao_ground_roll = ao_sample_roll_sum >> 9;
+ ao_sample_accel_along_sum = 0;
+ ao_sample_accel_across_sum = 0;
+ ao_sample_accel_through_sum = 0;
+ ao_sample_pitch_sum = 0;
+ ao_sample_yaw_sum = 0;
+ ao_sample_roll_sum = 0;
+ ao_orient = 0;
+
+ /* No rotation yet */
+ ao_quaternion_init_zero_rotation(&ao_rotation);
+
+ /* Take the pad IMU acceleration values and compute our current direction
+ */
+ ao_quaternion_init_vector(&ao_pad_orientation,
+ ao_ground_accel_across - ao_config.accel_zero_across,
+ ao_ground_accel_through - ao_config.accel_zero_through,
+ -ao_ground_accel_along - ao_config.accel_zero_along);
+
+ ao_quaternion_normalize(&ao_pad_orientation,
+ &ao_pad_orientation);
+
+#endif
+ nsamples = 0;
+}
+
+#if HAS_GYRO
+static void
+ao_sample_rotate(void)
+{
+#ifdef AO_FLIGHT_TEST
+ float dt = (ao_sample_tick - ao_sample_prev_tick) / 100.0;
+#else
+ static const float dt = 1/100.0;
+#endif
+ float x = ao_mpu6000_gyro(ao_sample_pitch - ao_ground_pitch) * dt;
+ float y = ao_mpu6000_gyro(ao_sample_yaw - ao_ground_yaw) * dt;
+ float z = ao_mpu6000_gyro(ao_sample_roll - ao_ground_roll) * dt;
+
+ float n_2, n;
+ float s, c;
+
+ struct ao_quaternion rot;
+ struct ao_quaternion point;
+
+ /* The amount of rotation is just the length of the vector. Now,
+ * here's the trick -- assume that the rotation amount is small. In this case,
+ * sin(x) ≃ x, so we can just make this the sin.
+ */
+
+ n_2 = x*x + y*y + z*z;
+ n = sqrtf(n_2);
+ s = n / 2;
+ if (s > 1)
+ s = 1;
+ c = sqrtf(1 - s*s);
+
+ /* Make unit vector */
+ if (n > 0) {
+ x /= n;
+ y /= n;
+ z /= n;
+ }
+
+ /* Now compute the unified rotation quaternion */
+
+ ao_quaternion_init_rotation(&rot,
+ x, y, z,
+ s, c);
+
+ /* Integrate with the previous rotation amount */
+ ao_quaternion_multiply(&ao_rotation, &ao_rotation, &rot);
+
+ /* And normalize to make sure it remains a unit vector */
+ ao_quaternion_normalize(&ao_rotation, &ao_rotation);
+
+ /* Compute pitch angle from vertical by taking the pad
+ * orientation vector and rotating it by the current total
+ * rotation value. That will be a unit vector pointing along
+ * the airframe axis. The Z value will be the cosine of the
+ * change in the angle from vertical since boost
+ */
+
+ ao_quaternion_rotate(&point, &ao_pad_orientation, &ao_rotation);
+
+ ao_orient = acosf(point.z) * (float) (180.0/M_PI);
+}
+#endif
static void
ao_sample_preflight(void)
* 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_sample_preflight_add();
} 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 = ao_pres_to_altitude(ao_ground_pres);
+ ao_sample_preflight_set();
ao_preflight = FALSE;
}
}
+/*
+ * While in pad mode, constantly update the ground state by
+ * re-averaging the data. This tracks changes in orientation, which
+ * might be caused by adjustments to the rocket on the pad and
+ * pressure, which might be caused by changes in the weather.
+ */
+
+static void
+ao_sample_preflight_update(void)
+{
+ if (nsamples < 512)
+ ao_sample_preflight_add();
+ else if (nsamples < 1024)
+ ++nsamples;
+ else
+ ao_sample_preflight_set();
+}
+
+#if 0
+#if HAS_GYRO
+static int32_t p_filt;
+static int32_t y_filt;
+
+static gyro_t inline ao_gyro(void) {
+ gyro_t p = ao_sample_pitch - ao_ground_pitch;
+ gyro_t y = ao_sample_yaw - ao_ground_yaw;
+
+ p_filt = p_filt - (p_filt >> 6) + p;
+ y_filt = y_filt - (y_filt >> 6) + y;
+
+ p = p_filt >> 6;
+ y = y_filt >> 6;
+ return ao_sqrt(p*p + y*y);
+}
+#endif
+#endif
+
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;
+ 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_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_data = (struct ao_data *) &ao_data_ring[ao_sample_data];
+ ao_sample_tick = ao_data->tick;
+
+#if HAS_BARO
+ 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;
+#endif
+
#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
- * = ------------ * ------------
- * 32767 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_sample_accel = ao_data_accel_cook(ao_data);
if (ao_config.pad_orientation != AO_PAD_ORIENTATION_ANTENNA_UP)
- ao_sample_accel = 0x7fff - ao_sample_accel;
- ao_adc->accel = ao_sample_accel;
+ ao_sample_accel = ao_data_accel_invert(ao_sample_accel);
+ ao_data_set_accel(ao_data, ao_sample_accel);
#endif
+#if HAS_GYRO
+ ao_sample_accel_along = ao_data_along(ao_data);
+ ao_sample_accel_across = ao_data_across(ao_data);
+ ao_sample_accel_through = ao_data_through(ao_data);
+ ao_sample_pitch = ao_data_pitch(ao_data);
+ ao_sample_yaw = ao_data_yaw(ao_data);
+ ao_sample_roll = ao_data_roll(ao_data);
#endif
if (ao_preflight)
ao_sample_preflight();
- else
+ else {
+ if (ao_flight_state < ao_flight_boost)
+ ao_sample_preflight_update();
ao_kalman();
- ao_sample_adc = ao_adc_ring_next(ao_sample_adc);
+#if HAS_GYRO
+ ao_sample_rotate();
+#endif
+ }
+#ifdef AO_FLIGHT_TEST
+ ao_sample_prev_tick = ao_sample_tick;
+#endif
+ ao_sample_data = ao_data_ring_next(ao_sample_data);
}
return !ao_preflight;
}
void
ao_sample_init(void)
{
+ ao_config_get();
nsamples = 0;
ao_sample_pres_sum = 0;
ao_sample_pres = 0;
ao_sample_accel_sum = 0;
ao_sample_accel = 0;
#endif
- ao_sample_adc = ao_adc_head;
+#if HAS_GYRO
+ ao_sample_accel_along_sum = 0;
+ ao_sample_accel_across_sum = 0;
+ ao_sample_accel_through_sum = 0;
+ ao_sample_accel_along = 0;
+ ao_sample_accel_across = 0;
+ ao_sample_accel_through = 0;
+ ao_sample_pitch_sum = 0;
+ ao_sample_yaw_sum = 0;
+ ao_sample_roll_sum = 0;
+ ao_sample_pitch = 0;
+ ao_sample_yaw = 0;
+ ao_sample_roll = 0;
+ ao_orient = 0;
+#endif
+ ao_sample_data = ao_data_head;
ao_preflight = TRUE;
}