ardupilot/libraries/AP_InertialSensor/AP_InertialSensor_Oilpan.cpp

132 lines
4.0 KiB
C++

/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
#include "AP_InertialSensor_Oilpan.h"
// ADC channel mappings on for the APM Oilpan
// Sensors: GYROX, GYROY, GYROZ, ACCELX, ACCELY, ACCELZ
const uint8_t AP_InertialSensor_Oilpan::_sensors[6] = { 1, 2, 0, 4, 5, 6 };
// ADC result sign adjustment for sensors.
const int8_t AP_InertialSensor_Oilpan::_sensor_signs[6] =
{ 1, -1, -1, 1, -1, -1 };
// ADC channel reading the gyro temperature
const uint8_t AP_InertialSensor_Oilpan::_gyro_temp_ch = 3;
// Maximum possible value returned by an offset-corrected sensor channel
const float AP_InertialSensor_Oilpan::_adc_constraint = 900;
// ADC : Voltage reference 3.3v / 12bits(4096 steps) => 0.8mV/ADC step
// ADXL335 Sensitivity(from datasheet) => 330mV/g,
// 0.8mV/ADC step => 330/0.8 = 412
// Tested value : 418
// Oilpan accelerometer scaling & offsets
#define OILPAN_ACCEL_SCALE_1G (GRAVITY * 2.0 / (2465.0 - 1617.0))
#define OILPAN_RAW_ACCEL_OFFSET ((2465.0 - 1617.0) / 2)
#define OILPAN_RAW_GYRO_OFFSET 1658.0
#define ToRad(x) (x*0.01745329252) // *pi/180
// IDG500 Sensitivity (from datasheet) => 2.0mV/degree/s,
// 0.8mV/ADC step => 0.8/3.33 = 0.4
// Tested values : 0.4026, ?, 0.4192
const float AP_InertialSensor_Oilpan::_gyro_gain_x = ToRad(0.4);
const float AP_InertialSensor_Oilpan::_gyro_gain_y = ToRad(0.41);
const float AP_InertialSensor_Oilpan::_gyro_gain_z = ToRad(0.41);
/* ------ Public functions -------------------------------------------*/
AP_InertialSensor_Oilpan::AP_InertialSensor_Oilpan( AP_ADC * adc ) :
_adc(adc)
{
}
uint16_t AP_InertialSensor_Oilpan::_init_sensor( AP_PeriodicProcess * scheduler)
{
_adc->Init(scheduler);
#if defined(DESKTOP_BUILD)
return AP_PRODUCT_ID_SITL;
#elif defined(__AVR_ATmega1280__)
return AP_PRODUCT_ID_APM1_1280;
#else
return AP_PRODUCT_ID_APM1_2560;
#endif
}
bool AP_InertialSensor_Oilpan::update()
{
float adc_values[6];
Vector3f gyro_offset = _gyro_offset.get();
Vector3f accel_scale = _accel_scale.get();
Vector3f accel_offset = _accel_offset.get();
_delta_time_micros = _adc->Ch6(_sensors, adc_values);
_temp = _adc->Ch(_gyro_temp_ch);
_gyro.x = _gyro_gain_x * _sensor_signs[0] * ( adc_values[0] - OILPAN_RAW_GYRO_OFFSET ) - gyro_offset.x;
_gyro.y = _gyro_gain_y * _sensor_signs[1] * ( adc_values[1] - OILPAN_RAW_GYRO_OFFSET ) - gyro_offset.y;
_gyro.z = _gyro_gain_z * _sensor_signs[2] * ( adc_values[2] - OILPAN_RAW_GYRO_OFFSET ) - gyro_offset.z;
_accel.x = accel_scale.x * _sensor_signs[3] * (adc_values[3] - OILPAN_RAW_ACCEL_OFFSET) * OILPAN_ACCEL_SCALE_1G - accel_offset.x;
_accel.y = accel_scale.y * _sensor_signs[4] * (adc_values[4] - OILPAN_RAW_ACCEL_OFFSET) * OILPAN_ACCEL_SCALE_1G - accel_offset.y;
_accel.z = accel_scale.z * _sensor_signs[5] * (adc_values[5] - OILPAN_RAW_ACCEL_OFFSET) * OILPAN_ACCEL_SCALE_1G - accel_offset.z;
/*
* X = 1619.30 to 2445.69
* Y = 1609.45 to 2435.42
* Z = 1627.44 to 2434.82
*/
return true;
}
bool AP_InertialSensor_Oilpan::new_data_available( void )
{
return _adc->new_data_available(_sensors);
}
float AP_InertialSensor_Oilpan::gx() {
return _gyro.x;
}
float AP_InertialSensor_Oilpan::gy() {
return _gyro.y;
}
float AP_InertialSensor_Oilpan::gz() {
return _gyro.z;
}
float AP_InertialSensor_Oilpan::ax() {
return _accel.x;
}
float AP_InertialSensor_Oilpan::ay() {
return _accel.y;
}
float AP_InertialSensor_Oilpan::az() {
return _accel.z;
}
float AP_InertialSensor_Oilpan::temperature() {
return _temp;
}
uint32_t AP_InertialSensor_Oilpan::get_delta_time_micros() {
return _delta_time_micros;
}
/* ------ Private functions -------------------------------------------*/
// return the oilpan gyro drift rate in radian/s/s
float AP_InertialSensor_Oilpan::get_gyro_drift_rate(void)
{
// 3.0 degrees/second/minute
return ToRad(3.0/60);
}
// get number of samples read from the sensors
uint16_t AP_InertialSensor_Oilpan::num_samples_available()
{
return _adc->num_samples_available(_sensors);
}