mirror of https://github.com/ArduPilot/ardupilot
127 lines
4.0 KiB
C++
127 lines
4.0 KiB
C++
#define ALLOW_DOUBLE_MATH_FUNCTIONS
|
|
|
|
#include "SIM_MS5611.h"
|
|
|
|
#include <SITL/SITL.h>
|
|
|
|
#include <stdio.h>
|
|
|
|
using namespace SITL;
|
|
|
|
// forward conversion, copied from driver:
|
|
void MS5611::convert_forward(int32_t D1, int32_t D2, float &P_Pa, float &Temp_C)
|
|
{
|
|
// _D1 and _D2 are stored as floats in driver
|
|
const float _D1 = D1;
|
|
const float _D2 = D2;
|
|
|
|
float dT;
|
|
float TEMP;
|
|
float OFF;
|
|
float SENS;
|
|
|
|
dT = _D2-(((uint32_t)prom[5])<<8);
|
|
TEMP = (dT * prom[6])/8388608;
|
|
OFF = prom[2] * 65536.0f + (prom[4] * dT) / 128;
|
|
SENS = prom[1] * 32768.0f + (prom[3] * dT) / 256;
|
|
|
|
TEMP += 2000;
|
|
|
|
if (TEMP < 2000) {
|
|
// second order temperature compensation when under 20 degrees C
|
|
float T2 = (dT*dT) / 0x80000000;
|
|
float Aux = sq(TEMP-2000.0);
|
|
float OFF2 = 2.5f*Aux;
|
|
float SENS2 = 1.25f*Aux;
|
|
if (TEMP < -1500) {
|
|
// extra compensation for temperatures below -15C
|
|
OFF2 += 7 * sq(TEMP+1500);
|
|
SENS2 += sq(TEMP+1500) * 11.0*0.5;
|
|
}
|
|
TEMP = TEMP - T2;
|
|
OFF = OFF - OFF2;
|
|
SENS = SENS - SENS2;
|
|
}
|
|
|
|
P_Pa = (_D1*SENS/2097152 - OFF)/32768;
|
|
Temp_C = TEMP * 0.01f;
|
|
}
|
|
|
|
void MS5611::convert(float P_Pa, float Temp_C, uint32_t &D1, uint32_t &D2)
|
|
{
|
|
const uint8_t Q1 = Qx_coeff[0];
|
|
const uint8_t Q2 = Qx_coeff[1];
|
|
const uint8_t Q3 = Qx_coeff[2];
|
|
const uint8_t Q4 = Qx_coeff[3];
|
|
const uint8_t Q5 = Qx_coeff[4];
|
|
const uint8_t Q6 = Qx_coeff[5];
|
|
|
|
const float TEMP = Temp_C * 100;
|
|
|
|
// second order temperature compensation when under 20 degrees C
|
|
if (TEMP < 2000) {
|
|
// Solve the quadratic equation for D2 when TEMP < 2000
|
|
D2 = 128 * (2 * int64_t(prom[5]) - sqrt(sq(int64_t(prom[6])) - 131072 * (TEMP - 2000)) + int64_t(prom[6]));
|
|
|
|
// Must compute the pressure compensation values using D2
|
|
const float dT = float(D2) - (int64_t(prom[5]) << Q5);
|
|
float TEMP_forward = 2000 + (dT * int64_t(prom[6])) / (1L << Q6);
|
|
float OFF = int64_t(prom[2]) * (1L << Q2) + (int64_t(prom[4]) * dT) / (1L << Q4);
|
|
float SENS = int64_t(prom[1]) * (1L << Q1) + (int64_t(prom[3]) * dT) / (1L << Q3);
|
|
|
|
const float Aux = sq(TEMP_forward - 2000);
|
|
float OFF2 = 2.5 * Aux;
|
|
float SENS2 = 1.25 * Aux;
|
|
if (TEMP < -1500) {
|
|
// extra compensation for temperatures below -15C
|
|
OFF2 += 7 * sq(TEMP_forward + 1500);
|
|
SENS2 += sq(TEMP_forward + 1500) * 11.0 * 0.5;
|
|
}
|
|
|
|
OFF = OFF - OFF2;
|
|
SENS = SENS - SENS2;
|
|
|
|
D1 = ((P_Pa * float(1L << 15) + OFF) * float(1L << 21)) / SENS;
|
|
} else {
|
|
const float dT = (TEMP - 2000) * (1L << Q6) / int64_t(prom[6]);
|
|
const float OFF = int64_t(prom[2]) * (1L << Q2) + (int64_t(prom[4]) * dT) / (1L << Q4);
|
|
const float SENS = int64_t(prom[1]) * (1L << Q1) + (int64_t(prom[3]) * dT) / (1L << Q3);
|
|
|
|
D1 = ((P_Pa * float(1L << 15) + OFF) * float(1L << 21)) / SENS;
|
|
D2 = dT + (int64_t(prom[5]) << Q5);
|
|
}
|
|
}
|
|
|
|
void MS5611::check_conversion_accuracy(float P_Pa, float Temp_C, uint32_t D1, uint32_t D2)
|
|
{
|
|
float f_P_Pa;
|
|
float f_Temp_C;
|
|
convert_forward(D1, D2, f_P_Pa, f_Temp_C);
|
|
|
|
if (fabs(f_P_Pa - P_Pa) > 0.2) {
|
|
AP_HAL::panic("Invalid pressure conversion");
|
|
}
|
|
if (fabs(f_Temp_C - Temp_C) > 0.02) {
|
|
AP_HAL::panic("Invalid temperature conversion");
|
|
}
|
|
}
|
|
|
|
void MS5611::get_pressure_temperature_readings(float &P_Pa, float &Temp_C)
|
|
{
|
|
float sigma, delta, theta;
|
|
|
|
float sim_alt = AP::sitl()->state.altitude;
|
|
sim_alt += 2 * rand_float();
|
|
|
|
AP_Baro::SimpleAtmosphere(sim_alt * 0.001f, sigma, delta, theta);
|
|
P_Pa = SSL_AIR_PRESSURE * delta;
|
|
|
|
Temp_C = KELVIN_TO_C(SSL_AIR_TEMPERATURE * theta) + AP::sitl()->temp_board_offset;
|
|
|
|
// TO DO add in temperature adjustment by inheritting from AP_Baro_SITL_Generic?
|
|
// AP_Baro_SITL::temperature_adjustment(P_Pa, Temp_C);
|
|
|
|
// TO DO add in wind correction by inheritting from AP_Baro_SITL_Generic?
|
|
// P_Pa += AP_Baro_SITL::wind_pressure_correction(instance);
|
|
}
|