/** ****************************************************************************** * @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 "airspeed.h" #include "airspeedsettings.h" #include "baroairspeed.h" // object that will be updated by the module #if defined(PIOS_INCLUDE_MPXV7002) || defined (PIOS_INCLUDE_MPXV5004) #define SAMPLING_DELAY_MS_MPXV 10 //Update at 100Hz #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 100.0f //Needs to be settable in a UAVO // Private types // Private variables // Private functions static uint16_t calibrationCount=0; void baro_airspeedGetAnalog(BaroAirspeedData *baroAirspeedData, portTickType *lastSysTime, uint8_t airspeedSensorType, int8_t airspeedADCPin){ //Ensure that the ADC pin is properly configured if(airspeedADCPin <0){ //It's not, so revert to former sensor type baroAirspeedData->BaroConnected = BAROAIRSPEED_BAROCONNECTED_FALSE; return; } //Wait until our turn //THIS SHOULD BE, IF OUR TURN GO IN, OTHERWISE CONTINUE vTaskDelayUntil(lastSysTime, SAMPLING_DELAY_MS_MPXV / portTICK_RATE_MS); //Calibrate sensor by averaging zero point value //THIS SHOULD NOT BE DONE IF THERE IS AN IN-AIR RESET. HOW TO DETECT THIS? if (calibrationCount < CALIBRATION_IDLE_MS/SAMPLING_DELAY_MS_MPXV) { //First let sensor warm up and stabilize. calibrationCount++; return; } else if (calibrationCount <= (CALIBRATION_IDLE_MS + CALIBRATION_COUNT_MS)/SAMPLING_DELAY_MS_MPXV) { //Then compute the average. calibrationCount++; /*DO NOT MOVE FROM BEFORE sensorCalibration=... LINE, OR ELSE WILL HAVE DIVIDE BY ZERO */ uint16_t sensorCalibration; if(airspeedSensorType==AIRSPEEDSETTINGS_AIRSPEEDSENSORTYPE_DIYDRONESMPXV7002){ sensorCalibration=PIOS_MPXV7002_Calibrate(airspeedADCPin, calibrationCount-CALIBRATION_IDLE_MS/SAMPLING_DELAY_MS_MPXV); PIOS_MPXV7002_UpdateCalibration(sensorCalibration); //This makes sense for the user if the initial calibration was not good and the user does not wish to reboot. } else if(airspeedSensorType==AIRSPEEDSETTINGS_AIRSPEEDSENSORTYPE_DIYDRONESMPXV5004){ sensorCalibration=PIOS_MPXV5004_Calibrate(airspeedADCPin, calibrationCount-CALIBRATION_IDLE_MS/SAMPLING_DELAY_MS_MPXV); PIOS_MPXV5004_UpdateCalibration(sensorCalibration); //This makes sense for the user if the initial calibration was not good and the user does not wish to reboot. } baroAirspeedData->BaroConnected = BAROAIRSPEED_BAROCONNECTED_TRUE; //Set settings UAVO. The airspeed UAVO is set elsewhere in the function. if (calibrationCount == (CALIBRATION_IDLE_MS + CALIBRATION_COUNT_MS)/SAMPLING_DELAY_MS_MPXV) AirspeedSettingsZeroPointSet(&sensorCalibration); return; } //Get CAS float calibratedAirspeed=0; if(airspeedSensorType==AIRSPEEDSETTINGS_AIRSPEEDSENSORTYPE_DIYDRONESMPXV7002){ calibratedAirspeed = PIOS_MPXV7002_ReadAirspeed(airspeedADCPin); if (calibratedAirspeed < 0) //This only occurs when there's a bad ADC reading. return; //Get sensor value, just for telemetry purposes. //This is a silly waste of resources, and should probably be removed at some point in the future. //At this time, PIOS_MPXV7002_Measure() should become a static function and be removed from the header file. // //Moreover, due to the way the ADC driver is currently written, this code will return 0 more often than //not. This is something that will have to change on the ADC side of things. baroAirspeedData->SensorValue=PIOS_MPXV7002_Measure(airspeedADCPin); } else if(airspeedSensorType==AIRSPEEDSETTINGS_AIRSPEEDSENSORTYPE_DIYDRONESMPXV5004){ calibratedAirspeed = PIOS_MPXV5004_ReadAirspeed(airspeedADCPin); if (calibratedAirspeed < 0) //This only occurs when there's a bad ADC reading. return; //Get sensor value, just for telemetry purposes. //This is a silly waste of resources, and should probably be removed at some point in the future. //At this time, PIOS_MPXV7002_Measure() should become a static function and be removed from the header file. // //Moreover, due to the way the ADC driver is currently written, this code will return 0 more often than //not. This is something that will have to change on the ADC side of things. baroAirspeedData->SensorValue=PIOS_MPXV5004_Measure(airspeedADCPin); } //Filter CAS float alpha=SAMPLING_DELAY_MS_MPXV/(SAMPLING_DELAY_MS_MPXV + ANALOG_BARO_AIRSPEED_TIME_CONSTANT_MS); //Low pass filter. float filteredAirspeed = calibratedAirspeed*(alpha) + baroAirspeedData->CalibratedAirspeed*(1.0f-alpha); //Set two values, one for the UAVO airspeed sensor reading, and the other for the GPS corrected one baroAirspeedData->CalibratedAirspeed = filteredAirspeed; } #endif /** * @} * @} */