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LibrePilot/flight/modules/Airspeed/baro_airspeed_mpxv.c
2015-05-13 21:55:18 +02:00

123 lines
4.7 KiB
C

/**
******************************************************************************
* @addtogroup OpenPilotModules OpenPilot Modules
* @{
* @addtogroup AirspeedModule Airspeed Module
* @brief Communicate with airspeed sensors and return values
* @{
*
* @file baro_airspeed.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
* @brief Airspeed module, handles temperature and pressure readings from BMP085
*
* @see The GNU Public License (GPL) Version 3
*
*****************************************************************************/
/*
* 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; either version 3 of the License, or
* (at your option) any later version.
*
* 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
*/
/**
* Output object: BaroAirspeed
*
* This module will periodically update the value of the BaroAirspeed object.
*
*/
#include "openpilot.h"
#include "hwsettings.h"
#include "airspeedsettings.h"
#include "airspeedsensor.h" // object that will be updated by the module
#include "airspeedalarm.h"
#if defined(PIOS_INCLUDE_MPXV)
#define CALIBRATION_IDLE_MS 2000 // Time to wait before calibrating, in [ms]
#define CALIBRATION_COUNT_MS 2000 // Time to spend calibrating, in [ms]
#define ANALOG_BARO_AIRSPEED_TIME_CONSTANT_MS 256 // low pass filter
// Private types
// Private variables
// Private functions
static uint16_t calibrationCount = 0;
PIOS_MPXV_descriptor sensor = { .type = PIOS_MPXV_UNKNOWN };
void baro_airspeedGetMPXV(AirspeedSensorData *airspeedSensor, AirspeedSettingsData *airspeedSettings, int8_t airspeedADCPin)
{
// Ensure that the ADC pin is properly configured
if (airspeedADCPin < 0) {
airspeedSensor->SensorConnected = AIRSPEEDSENSOR_SENSORCONNECTED_FALSE;
AirspeedAlarm(SYSTEMALARMS_ALARM_ERROR);
return;
}
if (sensor.type == PIOS_MPXV_UNKNOWN) {
switch (airspeedSettings->AirspeedSensorType) {
case AIRSPEEDSETTINGS_AIRSPEEDSENSORTYPE_DIYDRONESMPXV7002:
sensor = PIOS_MPXV_7002_DESC(airspeedADCPin);
break;
case AIRSPEEDSETTINGS_AIRSPEEDSENSORTYPE_DIYDRONESMPXV5004:
sensor = PIOS_MPXV_5004_DESC(airspeedADCPin);
break;
default:
airspeedSensor->SensorConnected = AIRSPEEDSENSOR_SENSORCONNECTED_FALSE;
AirspeedAlarm(SYSTEMALARMS_ALARM_ERROR);
return;
}
}
airspeedSensor->SensorValue = PIOS_MPXV_Measure(&sensor);
if (!airspeedSettings->ZeroPoint) {
AirspeedAlarm(SYSTEMALARMS_ALARM_WARNING);
// Calibrate sensor by averaging zero point value
if (calibrationCount < CALIBRATION_IDLE_MS / airspeedSettings->SamplePeriod) { // First let sensor warm up and stabilize.
calibrationCount++;
return;
} else if (calibrationCount <= (CALIBRATION_IDLE_MS + CALIBRATION_COUNT_MS) / airspeedSettings->SamplePeriod) { // Then compute the average.
calibrationCount++; /*DO NOT MOVE FROM BEFORE sensorCalibration=... LINE, OR ELSE WILL HAVE DIVIDE BY ZERO */
PIOS_MPXV_Calibrate(&sensor, airspeedSensor->SensorValue);
// Set settings UAVO. The airspeed UAVO is set elsewhere in the function.
if (calibrationCount > (CALIBRATION_IDLE_MS + CALIBRATION_COUNT_MS) / airspeedSettings->SamplePeriod) {
airspeedSettings->ZeroPoint = sensor.zeroPoint;
AirspeedSettingsZeroPointSet(&airspeedSettings->ZeroPoint);
}
return;
}
}
sensor.zeroPoint = airspeedSettings->ZeroPoint;
sensor.scale = airspeedSettings->Scale;
// Filter CAS : airspeedSettings->SamplePeriod value is 0 - 255 range
float alpha = 1 - (airspeedSettings->SamplePeriod / ANALOG_BARO_AIRSPEED_TIME_CONSTANT_MS); // Low pass filter.
airspeedSensor->CalibratedAirspeed = PIOS_MPXV_CalcAirspeed(&sensor, airspeedSensor->SensorValue) * (alpha) + airspeedSensor->CalibratedAirspeed * (1.0f - alpha);
airspeedSensor->SensorConnected = AIRSPEEDSENSOR_SENSORCONNECTED_TRUE;
AirspeedAlarm(SYSTEMALARMS_ALARM_OK);
}
#endif /* if defined(PIOS_INCLUDE_MPXV) */
/**
* @}
* @}
*/