DCM AHRS algorithm ported to mbed from Pololu MinIMU-9 in turn ported from ArduPilot 1.5 revised in a more OO style, though no done yet. More...

#include <DCM.h>

Public Member Functions
	DCM (void)
	Creates a new DCM AHRS algorithm object.
void	Update_step (void)
	A single update cycle for the algorithm; updates the matrix, normalizes it, corrects for gyro drift on 3 axes, (does not yet adjust for acceleration).
Data Fields
float	roll
	Output: Euler angle: roll.
float	pitch
	Output: Euler angle: pitch.
float	yaw
	Output: Euler angle: yaw.
int	gyro_x
	Input gyro sensor reading X-axis.
int	gyro_y
	Input gyro sensor reading Y-axis.
int	gyro_z
	Input gyro sensor reading Z-axis.
int	accel_x
	Input accelerometer sensor reading X-axis.
int	accel_y
	Input accelerometer sensor reading Y-axis.
int	accel_z
	Input accelerometer sensor reading Z-axis.
float	c_magnetom_x
	Input for the offset corrected & scaled magnetometer reading, X-axis.
float	c_magnetom_y
	Input for the offset corrected & scaled magnetometer reading, Y-axis.
float	c_magnetom_z
	Input for the offset corrected & scaled magnetometer reading, Z-axis.
float	MAG_Heading
	Input for the calculated magnetic heading.
float	speed_3d
	Input for the speed (ie, the magnitude of the 3d velocity vector.
float	G_Dt
	Input for the integration time (DCM algorithm)

Detailed Description

DCM AHRS algorithm ported to mbed from Pololu MinIMU-9 in turn ported from ArduPilot 1.5 revised in a more OO style, though no done yet.

Early version. There's more to do here but it's a start, at least.

Warning: Interface will most likely change.

Expects to see a Sensors.h in your project, as follows, with functions that read sensors and set the appropriate "input" member variables below. Eventually I'll change this to a better encapsulated OOP approach.

This approach of an external Sensors.* is an abstraction layer that makes it much, much easier to swap in a different sensor suite versus the original code. You can use Serial, I2C, SPI, Analog, whatever you want, whatever it takes as long as you populate the gyro, accel, and mag vectors before calling Update_step()

 #ifndef __SENSORS_H
 #define __SENSORS_H

 void Gyro_Init(void);
 void Read_Gyro(void);
 void Accel_Init(void);
 void Read_Accel(void);
 void Compass_Init(void);
 void Read_Compass(void);
 void Calculate_Offsets(void);
 void Compass_Heading(void);
 
 #endif

Definition at line 96 of file DCM.h.

Constructor & Destructor Documentation

DCM ( void )

Creates a new DCM AHRS algorithm object.

Definition at line 53 of file DCM.cpp.

Member Function Documentation

void Update_step ( void )

A single update cycle for the algorithm; updates the matrix, normalizes it, corrects for gyro drift on 3 axes, (does not yet adjust for acceleration).

Magnetometer update is run less often than gyro/accelerometer-based update

Definition at line 245 of file DCM.cpp.