Compass Sensor [HiTechnic]

Files
file	HTMC-driver.h
	HiTechnic Magnetic Compass Sensor Driver.
Defines
#define	HTMC_I2C_ADDR   0x02
#define	HTMC_MODE   0x41
#define	HTMC_HEAD_U   0x42
#define	HTMC_HEAD_L   0x43
#define	HTMC_MEASURE_CMD   0x00
#define	HTMC_CALIBRATE_CMD   0x43
Functions
bool	HTMCstartCal (tSensors link)
bool	HTMCstopCal (tSensors link)
int	HTMCreadHeading (tSensors link)
int	HTMCreadRelativeHeading (tSensors link)
int	HTMCsetTarget (tSensors link, int offset=0)
int	HTMCreadHeading (tMUXSensor muxsensor)
int	HTMCreadRelativeHeading (tMUXSensor muxsensor)
int	HTMCsetTarget (tMUXSensor muxsensor, int offset=0)
Variables
tConfigParams	HTMC_config = {HTSMUX_CHAN_I2C, 2, 0x02, 0x42}
tByteArray	HTMC_I2CRequest
tByteArray	HTMC_I2CReply
int	target [][]

---

Detailed Description

HiTechnic Compass Sensor

---

Define Documentation

#define HTMC_CALIBRATE_CMD   0x43

HTMC calibrate mode command

Definition at line 52 of file HTMC-driver.h.

#define HTMC_HEAD_L   0x43

HTMC Heading Lower bit

Definition at line 48 of file HTMC-driver.h.

#define HTMC_HEAD_U   0x42

HTMC Heading Upper bits

Definition at line 47 of file HTMC-driver.h.

#define HTMC_I2C_ADDR   0x02

HTMC I2C device address

Definition at line 45 of file HTMC-driver.h.

#define HTMC_MEASURE_CMD   0x00

HTMC measurement mode command

Definition at line 51 of file HTMC-driver.h.

#define HTMC_MODE   0x41

HTMC Mode control

Definition at line 46 of file HTMC-driver.h.

---

Function Documentation

int HTMCreadHeading

(

tSensors

link )

Return the current absolute heading

Parameters:

link	the HTMC port number

Returns:

heading in degrees (0 - 359) or -1 if an error occurred.

Examples:

HTMC-SMUX-test1.c, and HTMC-test1.c.

Definition at line 134 of file HTMC-driver.h.

int HTMCreadHeading

(

tMUXSensor

muxsensor )

Return the current absolute heading

Parameters:

muxsensor

the SMUX sensor port number

Returns:

heading in degrees (0 - 359) or -1 if an error occurred.

Definition at line 158 of file HTMC-driver.h.

int HTMCreadRelativeHeading

(

tSensors

link )

Return the current relative heading, value between -179 and 180

Parameters:

link	the HTMC port number

Returns:

relative heading in degrees or -255 if an error occurred.

Examples:

HTMC-SMUX-test1.c, and HTMC-test1.c.

Definition at line 179 of file HTMC-driver.h.

int HTMCreadRelativeHeading

(

tMUXSensor

muxsensor )

Return the current relative heading, value between -179 and 180

Parameters:

muxsensor

the SMUX sensor port number

Returns:

relative heading in degrees or -255 if an error occurred.

Definition at line 193 of file HTMC-driver.h.

int HTMCsetTarget	(	tSensors	link,
		int	offset
	)

Set the value for the offset to be used as the new zero-point for the relative heading returned by HTMCreadRelativeHeading()

Parameters:

link	the HTMC port number
offset	to be used to calculate relative heading (0-360 degrees). If unspecified, uses current heading.

Returns:

the current target heading

Examples:

HTMC-SMUX-test1.c, and HTMC-test1.c.

Definition at line 211 of file HTMC-driver.h.

int HTMCsetTarget	(	tMUXSensor	muxsensor,
		int	offset
	)

Set the value for the offset to be used as the new zero-point for the relative heading returned by HTMCreadRelativeHeading()

Parameters:

muxsensor	the SMUX sensor port number
offset	to be used to calculate relative heading (0-360 degrees). If unspecified, uses current heading.

Definition at line 224 of file HTMC-driver.h.

bool HTMCstartCal

(

tSensors

link )

Start the calibration. The sensor should be rotated a little more than 360 along the horizontal plane in no less than 20 seconds. After the sensor has been rotated, call HTMCstopCal() to set the sensor back in measurement mode and save the calibration data. This calibration data is stored in the sensor until the next calibration.

Parameters:

link	the HTMC port number

Returns:

true if no error occured, false if it did

Examples:

HTMC-test2.c.

Definition at line 86 of file HTMC-driver.h.

bool HTMCstopCal

(

tSensors

link )

Stop the calibration. This should be called no less than 20 seconds after HTMCstartCal() and only if the sensor has been rotated more than 360 degrees

Parameters:

link	the HTMC port number

Returns:

true if no error occured, false if it did

Examples:

HTMC-test2.c.

Definition at line 105 of file HTMC-driver.h.

---

Variable Documentation

tConfigParams HTMC_config = {HTSMUX_CHAN_I2C, 2, 0x02, 0x42}

Array to hold SMUX config data for sensor

Definition at line 65 of file HTMC-driver.h.

tByteArray HTMC_I2CReply

Array to hold I2C reply data

Definition at line 69 of file HTMC-driver.h.

tByteArray HTMC_I2CRequest

Array to hold I2C command data

Definition at line 68 of file HTMC-driver.h.

int target[][]

Initial value:

 {{0, 0, 0, 0},   
                  {0, 0, 0, 0},
                  {0, 0, 0, 0},
                  {0, 0, 0, 0}}

Definition at line 71 of file HTMC-driver.h.