Airspeed sensor module using the MS45xxDO digital pressure sensor via I2C. More...

#include "std.h"
#include "mcu_periph/i2c.h"
#include "modules/sensors/airspeed_ms45xx_i2c.h"
#include "filters/low_pass_filter.h"
#include "subsystems/abi.h"
#include "mcu_periph/uart.h"
#include "pprzlink/messages.h"
#include "subsystems/datalink/downlink.h"
#include "subsystems/datalink/telemetry.h"

Include dependency graph for airspeed_ms45xx_i2c.c:

Go to the source code of this file.

Macros
#define	MS45XX_I2C_DEV i2c2
	Default I2C device. More...

#define	MS45XX_I2C_ADDR 0x50
	Sensor I2C slave address (existing defaults 0x50, 0x6C and 0x8C) More...

#define	MS45XX_PRESSURE_OUTPUT_TYPE_InH2O 0
	MS45xx sensors pressure output type can be in PSI or InH2O, as defined in the datasheet if not defined to be MS45XX_PRESSURE_OUTPUT_TYPE_InH2O then PSI is used. More...

#define	MS45XX_PRESSURE_RANGE 1
	MS45xx pressure range in PSI or InH2O The sensor is available in many ranges, the datasheet of your pressure sensor will tell which one and what this range represents. More...

#define	MS45XX_PRESSURE_TYPE 0
	Pressure Type 0 = Differential, 1 = Gauge note there are theoretical more types than 2, e.g. More...

#define	USE_AIRSPEED_LOWPASS_FILTER TRUE
	Use low pass filter on pressure values. More...

#define	MS45XX_OUTPUT_TYPE 0
	MS45xx output Type. More...

#define	InH2O_TO_PA 249.08891
	Conversion factor from InH2O to Pa. More...

#define	PSI_TO_PA 6894.75729
	Conversion factor from psi to Pa. More...

#define	OutputPressureToPa PSI_TO_PA

#define	MS45XX_PRESSURE_SCALE (2 * MS45XX_PRESSURE_RANGE / (0.8 * 16383) * OutputPressureToPa)

#define	MS45XX_PRESSURE_OFFSET (1.25 * MS45XX_PRESSURE_RANGE * OutputPressureToPa)

#define	MS45XX_SYNC_SEND FALSE
	Send a AIRSPEED_MS45XX message with every new measurement. More...

#define	MS45XX_AIRSPEED_SCALE 1.6327
	Quadratic scale factor for indicated airspeed. More...

#define	MS45XX_LOWPASS_TAU 0.15
	Time constant for second order Butterworth low pass filter Default of 0.15 should give cut-off freq of 1/(2pitau) ~= 1Hz. More...

#define	AUTOSET_NB_MAX 20

Functions
static void	ms45xx_downlink (struct transport_tx trans, struct link_device dev)

void	ms45xx_i2c_init (void)

void	ms45xx_i2c_periodic (void)

void	ms45xx_i2c_event (void)

Variables
struct AirspeedMs45xx	ms45xx

static struct i2c_transaction	ms45xx_trans

static Butterworth2LowPass	ms45xx_filter

Detailed Description

Airspeed sensor module using the MS45xxDO digital pressure sensor via I2C.

Needs to be one of the versions with 14bit pressure and 11bit temperature.

Definition in file airspeed_ms45xx_i2c.c.

Macro Definition Documentation

#define AUTOSET_NB_MAX 20

Definition at line 215 of file airspeed_ms45xx_i2c.c.

Referenced by ms45xx_i2c_event().

#define InH2O_TO_PA 249.08891

Conversion factor from InH2O to Pa.

Definition at line 101 of file airspeed_ms45xx_i2c.c.

#define MS45XX_AIRSPEED_SCALE 1.6327

Quadratic scale factor for indicated airspeed.

airspeed = sqrt(2*p_diff/density) With p_diff in Pa and standard air density of 1.225 kg/m^3, default airspeed scale is 2/1.225

Definition at line 160 of file airspeed_ms45xx_i2c.c.

Referenced by ms45xx_i2c_init().

#define MS45XX_I2C_ADDR 0x50

Sensor I2C slave address (existing defaults 0x50, 0x6C and 0x8C)

Definition at line 62 of file airspeed_ms45xx_i2c.c.

Referenced by ms45xx_i2c_periodic().

#define MS45XX_I2C_DEV i2c2

Default I2C device.

Definition at line 56 of file airspeed_ms45xx_i2c.c.

Referenced by ms45xx_i2c_periodic().

#define MS45XX_LOWPASS_TAU 0.15

Time constant for second order Butterworth low pass filter Default of 0.15 should give cut-off freq of 1/(2*pi*tau) ~= 1Hz.

Definition at line 167 of file airspeed_ms45xx_i2c.c.

Referenced by ms45xx_i2c_init().

#define MS45XX_OUTPUT_TYPE 0

MS45xx output Type.

0 = Output Type A with 10% to 90% 1 = Output Type B with 5% to 95%

Definition at line 97 of file airspeed_ms45xx_i2c.c.

#define MS45XX_PRESSURE_OFFSET (1.25 * MS45XX_PRESSURE_RANGE * OutputPressureToPa)

Definition at line 127 of file airspeed_ms45xx_i2c.c.

Referenced by ms45xx_i2c_init().

#define MS45XX_PRESSURE_OUTPUT_TYPE_InH2O 0

MS45xx sensors pressure output type can be in PSI or InH2O, as defined in the datasheet if not defined to be MS45XX_PRESSURE_OUTPUT_TYPE_InH2O then PSI is used.

Definition at line 69 of file airspeed_ms45xx_i2c.c.

#define MS45XX_PRESSURE_RANGE 1

MS45xx pressure range in PSI or InH2O The sensor is available in many ranges, the datasheet of your pressure sensor will tell which one and what this range represents.

Definition at line 77 of file airspeed_ms45xx_i2c.c.

#define MS45XX_PRESSURE_SCALE (2 * MS45XX_PRESSURE_RANGE / (0.8 * 16383) * OutputPressureToPa)

Definition at line 124 of file airspeed_ms45xx_i2c.c.

Referenced by ms45xx_i2c_init().

#define MS45XX_PRESSURE_TYPE 0

Pressure Type 0 = Differential, 1 = Gauge note there are theoretical more types than 2, e.g.

Absolute not implemented

Definition at line 83 of file airspeed_ms45xx_i2c.c.

Referenced by ms45xx_i2c_init().

#define MS45XX_SYNC_SEND FALSE

Send a AIRSPEED_MS45XX message with every new measurement.

Mainly for debugging, use with caution, sends message at ~100Hz.