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OP-1273 New files for the MS4525DO PixHawk speed sensor: PIOS files and module files

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Andrés Chavarría Krauser 2014-03-25 09:24:08 +01:00 committed by Andrecillo
parent f8f53d8801
commit 4dff86dc9c
4 changed files with 389 additions and 0 deletions
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174
flight/modules/Airspeed/baro_airspeed_ms4525do.c Normal file
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/**
******************************************************************************
* @addtogroup OpenPilotModules OpenPilot Modules
* @{
* @addtogroup AirspeedModule Airspeed Module
* @brief Communicate with airspeed sensors and return values
* @{
*
* @file baro_airspeed_ms4525do.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2014.
* @brief Airspeed module, handles temperature and pressure readings from MS4525DO
*
* @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 "taskinfo.h"
#if defined(PIOS_INCLUDE_MS4525DO)
#define CALIBRATION_IDLE_MS 0 // Time to wait before calibrating, in [ms]
#define CALIBRATION_COUNT_MS 4000 // Time to spend calibrating, in [ms]
#define FILTER_SHIFT 5 // Barry Dorr filter parameter k
#define P0 101325.0f // standard pressure
#define CCEXPONENT 0.2857142857f // exponent of compressibility correction 2/7
#define CASFACTOR 760.8802669f // sqrt(5) * speed of sound at standard
#define TASFACTOR 0.05891022589f // 1/sqrt(T0)
#define max(x,y) ((x)>=(y) ? (x) : (y))
// Private types
// Private functions
static int8_t baro_airspeedReadMS4525DO(AirspeedSensorData *airspeedSensor, AirspeedSettingsData *airspeedSettings);
// Private variables
static uint16_t calibrationCount = 0;
static uint32_t filter_reg; // Barry Dorr filter register
void baro_airspeedGetMS4525DO(AirspeedSensorData *airspeedSensor, AirspeedSettingsData *airspeedSettings)
{
// request measurement first
int8_t retVal = PIOS_MS4525DO_Request();
if( retVal !=0 ){
AlarmsSet(SYSTEMALARMS_ALARM_I2C, SYSTEMALARMS_ALARM_ERROR);
return;
}
// Datasheet of MS4525DO: conversion needs 0.5 ms + 20% more when status bit used
// delay by one Tick or at least 2 ms
const portTickType xDelay = max(2 / portTICK_RATE_MS, 1);
vTaskDelay( xDelay );
// read the sensor
retVal = baro_airspeedReadMS4525DO(airspeedSensor,airspeedSettings);
switch( retVal ){
case 0 : AlarmsClear(SYSTEMALARMS_ALARM_I2C);
break;
case -4 :
case -5 : AlarmsSet(SYSTEMALARMS_ALARM_I2C, SYSTEMALARMS_ALARM_WARNING);
break;
case -1 :
case -2 :
case -3 :
case -6 :
default : AlarmsSet(SYSTEMALARMS_ALARM_I2C, SYSTEMALARMS_ALARM_ERROR);
}
}
static int8_t baro_airspeedReadMS4525DO(AirspeedSensorData *airspeedSensor, AirspeedSettingsData *airspeedSettings)
{
// Check to see if airspeed sensor is returning airspeedSensor
uint16_t values[2];
int8_t retVal=PIOS_MS4525DO_Read(values);
if( retVal == 0 ){
airspeedSensor->SensorValue = values[0];
airspeedSensor->SensorValueTemperature = values[1];
} else {
airspeedSensor->SensorValue = -1;
airspeedSensor->SensorValueTemperature = -1;
airspeedSensor->SensorConnected = AIRSPEEDSENSOR_SENSORCONNECTED_FALSE;
airspeedSensor->CalibratedAirspeed = 0;
return retVal;
}
// only calibrate if no stored calibration is available
if ( !airspeedSettings->ZeroPoint ) {
// Calibrate sensor by averaging zero point value
if (calibrationCount <= CALIBRATION_IDLE_MS / airspeedSettings->SamplePeriod) {
calibrationCount++;
filter_reg = (airspeedSensor->SensorValue << FILTER_SHIFT );
return retVal;
} else if (calibrationCount <= (CALIBRATION_IDLE_MS + CALIBRATION_COUNT_MS) / airspeedSettings->SamplePeriod) {
calibrationCount++;
// update filter register
filter_reg = filter_reg - ( filter_reg >> FILTER_SHIFT ) + airspeedSensor->SensorValue;
if (calibrationCount > (CALIBRATION_IDLE_MS + CALIBRATION_COUNT_MS) / airspeedSettings->SamplePeriod) {
// Scale output for unity gain.
airspeedSettings->ZeroPoint = (uint16_t)( filter_reg >> FILTER_SHIFT );
AirspeedSettingsZeroPointSet(&airspeedSettings->ZeroPoint);
calibrationCount = 0;
}
return retVal;
}
}
/* Compute airspeed
assume sensor is A Type and has a range of 1 psi, i.e. Pmin=-1.0 psi and Pmax=1.0 psi
Datasheet pressure: output = 0.8 * 16383 / (Pmax-Pmin) * (P - Pmin) + 0.1 * 16383
Inversion: P = (10*output - 81915)/65532 in psi
1 psi = 6894,757293168 Pa
P = (10*output - 81915)*0.1052120688 in Pa
Datasheet temperature: output = (T+50)*2047 / 200
Inversion: T = (200*out - 102350)/2047 in C
T = (200*out - 102350)/2047 + 273.15 in K
*/
const float dP = ( 10*(int32_t)(airspeedSensor->SensorValue-airspeedSettings->ZeroPoint) ) * 0.1052120688f;
const float T = (float)( 200*(int32_t)airspeedSensor->SensorValueTemperature - 102350) / 2047 + 273.15f;
airspeedSensor->DifferentialPressure = dP;
airspeedSensor->Temperature = T;
// CAS = Csound * sqrt( 5 *( (dP/P0 +1)^(2/7) - 1) )
// TAS = Csound * sqrt( 5 T/T0 *( (dP/P0 +1)^(2/7) - 1) )
// where Csound = 340.276 m/s at standard condition T0=288.15 K and P0 = 101315 Pa
airspeedSensor->CalibratedAirspeed = airspeedSettings->Scale * CASFACTOR * sqrtf( powf( fabsf(dP) / P0 + 1.0f , CCEXPONENT ) - 1.0f );
airspeedSensor->TrueAirspeed = airspeedSensor->CalibratedAirspeed * TASFACTOR * sqrtf( T );
airspeedSensor->SensorConnected = AIRSPEEDSENSOR_SENSORCONNECTED_TRUE;
return retVal;
}
#endif /* if defined(PIOS_INCLUDE_MS4525DO) */
/**
* @}
* @}
*/

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flight/modules/Airspeed/inc/baro_airspeed_ms4525do.h Normal file
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/**
******************************************************************************
* @addtogroup OpenPilotModules OpenPilot Modules
* @{
* @addtogroup AirspeedModule Airspeed Module
* @brief Calculate airspeed from measurements of differential pressure from a MS4525DO (PixHawk airspeed sensor)
* @{
*
* @file baro_airspeed_mas4525do.h
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2014.
* @brief Airspeed module, reads temperature and pressure from MS4525DO
*
* @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
*/
#ifndef BARO_AIRSPEED_MS4525DO_H
#define BARO_AIRSPEED_MS4525DO_H
#if defined(PIOS_INCLUDE_MS4525DO)
void baro_airspeedGetMS4525DO(AirspeedSensorData *airspeedSensor, AirspeedSettingsData *airspeedSettings);
#endif /* PIOS_INCLUDE_MS4525DO */
#endif // BARO_AIRSPEED_MS4525DO_H
/**
* @}
* @}
*/

127
flight/pios/common/pios_ms4525do.c Normal file
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/**
******************************************************************************
* @addtogroup PIOS PIOS Core hardware abstraction layer
* @{
* @addtogroup PIOS_MS4525DO MS4525DO Functions
* @brief Hardware functions to deal with the PixHawk Airspeed Sensor based on MS4525DO
* @{
*
* @file pios_ms4525do.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2014.
* @brief PixHawk MS4525DO Airspeed Sensor Driver
* @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
*/
#include "pios.h"
#ifdef PIOS_INCLUDE_MS4525DO
/* Local Defs and Variables */
static int8_t PIOS_MS4525DO_ReadI2C(uint8_t *buffer, uint8_t len);
static int8_t PIOS_MS4525DO_WriteI2C(uint8_t *buffer, uint8_t len);
static bool pios_ms4525do_requested = false;
static int8_t PIOS_MS4525DO_ReadI2C(uint8_t *buffer, uint8_t len)
{
const struct pios_i2c_txn txn_list[] = {
{
.info = __func__,
.addr = MS4525DO_I2C_ADDR,
.rw = PIOS_I2C_TXN_READ,
.len = len,
.buf = buffer,
}
};
return PIOS_I2C_Transfer(PIOS_I2C_MS4525DO_ADAPTER, txn_list, NELEMENTS(txn_list));
}
static int8_t PIOS_MS4525DO_WriteI2C(uint8_t *buffer, uint8_t len)
{
const struct pios_i2c_txn txn_list[] = {
{
.info = __func__,
.addr = MS4525DO_I2C_ADDR,
.rw = PIOS_I2C_TXN_WRITE,
.len = len,
.buf = buffer,
}
};
return PIOS_I2C_Transfer(PIOS_I2C_MS4525DO_ADAPTER, txn_list, NELEMENTS(txn_list));
}
int8_t PIOS_MS4525DO_Request(void)
{
// MS4525DO expects a zero length write.
// Sending one byte is a workaround that works for the moment
uint8_t data=0;
int8_t retVal=PIOS_MS4525DO_WriteI2C(&data,sizeof(data));
/* requested only when transfer worked */
pios_ms4525do_requested = ( retVal == 0 );
return retVal;
}
// values has to ba an arrray with two elements
// values stay untouched on error
int8_t PIOS_MS4525DO_Read(uint16_t *values)
{
if (!pios_ms4525do_requested) {
/* Do not try to read when not requested */
/* else probably stale data will be obtained */
return -4;
}
uint8_t data[4];
int8_t retVal=PIOS_MS4525DO_ReadI2C(data, sizeof(data));
uint8_t status = data[0] & 0xC0;
if (status == 0x80) {
/* stale data */
return -5;
} else if (status == 0xC0) {
/* device probably broken */
return -6;
}
/* differential pressure */
values[0] = (data[0] << 8);
values[0] += data[1];
/* temperature */
values[1] = (data[2] << 8);
values[1] += data[3];
values[1] = (values[1] >> 5);
/* not requested anymore, only when transfer worked */
pios_ms4525do_requested = !( retVal == 0 );
return retVal;
}
#endif /* PIOS_INCLUDE_MS4525DO */

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flight/pios/inc/pios_ms4525do.h Normal file
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/**
******************************************************************************
* @addtogroup PIOS PIOS Core hardware abstraction layer
* @{
* @addtogroup PIOS_MS4525DO MS4525DO Functions
* @brief Hardware functions to deal with the PixHawk Airspeed Sensor based on MS4525DO
* @{
*
* @file pios_ms4525do.h
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2014.
* @brief PixHawk MS4525DO Airspeed Sensor Driver
* @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
*/
#ifndef PIOS_MS4525DO_H
#define PIOS_MS4525DO_H
// Interface Type I chip
#define MS4525DO_I2C_ADDR 0x28
// Interface Type J chip
/* #define MS4525DO_I2C_ADDR 0x36 */
// Interface Type K chip
/* #define MS4525DO_I2C_ADDR 0x46 */
extern int8_t PIOS_MS4525DO_Request(void);
extern int8_t PIOS_MS4525DO_Read(uint16_t *values);
#endif /* PIOS_MS4525DO_H */