compass3d.h File Reference

This library provides convenience functions for reading measurements from the Parallax Compass Module 3-Axis HMC5883L.

CONSTRUCTION ZONE: This library is preliminary, major revisions pending. More...

#include "simplei2c.h"
#include "simpletools.h"

Go to the source code of this file.

Functions
void	compass_init (i2c *bus)
	Initialize the Compass. More...
void	compass_read (i2c *bus, int *px, int *py, int *pz)
	Read values from compass. More...

Detailed Description

This library provides convenience functions for reading measurements from the Parallax Compass Module 3-Axis HMC5883L.

CONSTRUCTION ZONE: This library is preliminary, major revisions pending.

Author

Andy Lindsay

Version

v0.85

Copyright

Copyright (C) Parallax, Inc. 2013. All Rights MIT Licensed.

Function Documentation

void compass_init

(

i2c *

bus)

Initialize the Compass.

This function initializes the compass, but before calling it, you have to set up an I2C bus. Example: Assuming the your program is using the simpletools library, you can use:

i2c mybus = i2c_init(sclPin, sdaPin)

... where sclPin is the number of the I/O pin connected to the compass module's SCL line and sdaPin is the number of the pin connected to the module's SDA line.

Parameters

I2C	bus pointer. In the example above, the pointer is mybus.

Returns

void, but it will display an error message if the compass module does not respond.

void compass_read	(	i2c *	bus,
		int *	px,
		int *	py,
		int *	pz
	)

Read values from compass.

This function finds a compass on the specified bus, reads its x, y, and z values and loads them into variables that are passed by address.

Parameters

*bus	A pointer to the I2C bus (mybus in the example above).
*px	A pointer to a variable to receive the x-value measurement.
*py	A pointer to a variable to receive the y-value measurement.
*pz	A pointer to a variable to receive the z-value measurement.

Returns

void, but it will display an error message if the compass module does not respond.