/** ****************************************************************************** * @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 #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 100 // 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; AlarmsSet(SYSTEMALARMS_ALARM_AIRSPEED, 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; AlarmsSet(SYSTEMALARMS_ALARM_AIRSPEED, SYSTEMALARMS_ALARM_ERROR); return; } } airspeedSensor->SensorValue = PIOS_MPXV_Measure(&sensor); if (!airspeedSettings->ZeroPoint) { AlarmsSet(SYSTEMALARMS_ALARM_AIRSPEED, 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; // Filter CAS float alpha = airspeedSettings->SamplePeriod / (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; AlarmsSet(SYSTEMALARMS_ALARM_AIRSPEED, SYSTEMALARMS_ALARM_OK); } #endif /* if defined(PIOS_INCLUDE_MPXV) */ /** * @} * @} */