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Saturday 7 January 2012

MBED Example: Hot to use Honeywell HMC6352 digital compass library.

.from: http://mbed.org/users/aberk/libraries/HMC6352/lijrmf

XxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXx HMC6352.cpp XxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXx

/**
 * @author Aaron Berk
 *
 * @section LICENSE
 *
 * Copyright (c) 2010 ARM Limited
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @section DESCRIPTION
 *
 * Honeywell HMC6352 digital compass.
 *
 * Datasheet:
 *
 * http://www.ssec.honeywell.com/magnetic/datasheets/HMC6352.pdf
 */

/**
 * Includes
 */
#include "HMC6352.h"

HMC6352::HMC6352(PinName sda, PinName scl) {

    i2c_ = new I2C(sda, scl);
    //100KHz, as specified by the datasheet.
    i2c_->frequency(100000);

    operationMode_ = getOpMode();

}

int HMC6352::sample(void) {

    char tx[1];
    char rx[2];

    if (operationMode_ == HMC6352_STANDBY || operationMode_ == HMC6352_QUERY) {
        tx[0] = HMC6352_GET_DATA;

        i2c_->write((HMC6352_I2C_ADDRESS << 1) & 0xFE, tx, 1);
        wait_ms(1);
    }

    i2c_->read((HMC6352_I2C_ADDRESS << 1) | 0x01, rx, 2);
    wait_ms(1);

    return (((int)rx[0] << 8) | (int)rx[1]);

}

void HMC6352::setSleepMode(int exitOrEnter) {

    char tx[1];

    tx[0] = exitOrEnter;

    i2c_->write((HMC6352_I2C_ADDRESS << 1) & 0xFE, tx, 1);
    wait_ms(1);

}

void HMC6352::setReset(void) {

    char tx[1];

    tx[0] = HMC6352_SET_RESET;

    i2c_->write((HMC6352_I2C_ADDRESS << 1) & 0xFE, tx, 1);
    wait_ms(7);

}

void HMC6352::setCalibrationMode(int exitOrEnter) {

    char tx[1];
    int delay = 0;

    tx[0] = exitOrEnter;

    if (exitOrEnter == HMC6352_EXIT_CALIB) {
        delay = 15;
    } else if (exitOrEnter == HMC6352_ENTER_CALIB) {
        delay = 1;
    }

    i2c_->write((HMC6352_I2C_ADDRESS << 1) & 0xFE, tx, 1);
    wait_ms(delay);

}

void HMC6352::saveOpMode(void) {

    char tx[1];

    tx[0] = HMC6352_SAVE_OPMODE;

    i2c_->write((HMC6352_I2C_ADDRESS << 1) & 0xFE, tx, 1);
    wait_ms(1);

}

int HMC6352::getSlaveAddress(void) {

    return read(HMC6352_EEPROM_READ, HMC6352_SLAVE_ADDR);

}

int HMC6352::getOffset(int axis) {

    char rx[2] = {0x00, 0x00};

    if (axis == HMC6352_MX_OFFSET) {

        rx[0] = read(HMC6352_EEPROM_READ, HMC6352_MX_OFF_MSB);
        rx[1] = read(HMC6352_EEPROM_READ, HMC6352_MX_OFF_LSB);

    } else if (axis == HMC6352_MY_OFFSET) {

        rx[0] = read(HMC6352_EEPROM_READ, HMC6352_MY_OFF_MSB);
        rx[1] = read(HMC6352_EEPROM_READ, HMC6352_MY_OFF_LSB);

    }

    return ((rx[0] << 8) | (rx[1]));

}

void HMC6352::setOffset(int axis, int offset) {

    char tx[2] = {0x00, 0x00};

    tx[0] = (offset & 0x0000FF00) >> 8;
    tx[1] = (offset & 0x000000FF);

    if (axis == HMC6352_MX_OFFSET) {

        write(HMC6352_EEPROM_WRITE, HMC6352_MX_OFF_MSB, tx[0]);
        write(HMC6352_EEPROM_WRITE, HMC6352_MX_OFF_MSB, tx[1]);

    } else if (axis == HMC6352_MY_OFFSET) {

        write(HMC6352_EEPROM_WRITE, HMC6352_MY_OFF_MSB, tx[0]);
        write(HMC6352_EEPROM_WRITE, HMC6352_MY_OFF_MSB, tx[1]);

    }

}

int HMC6352::getTimeDelay(void) {

    return read(HMC6352_EEPROM_READ, HMC6352_TIME_DELAY);

}

void HMC6352::setTimeDelay(int delay) {

    write(HMC6352_EEPROM_WRITE, HMC6352_TIME_DELAY, delay);

}

int HMC6352::getSumNumber(void) {

    return read(HMC6352_EEPROM_READ, HMC6352_SUMMED);

}

void HMC6352::setSumNumber(int sum) {

    write(HMC6352_EEPROM_WRITE, HMC6352_SUMMED, sum);

}

int HMC6352::getSoftwareVersion(void) {

    return read(HMC6352_EEPROM_READ, HMC6352_SOFT_VER);

}

int HMC6352::getOpMode(void) {

    int response = 0;

    response = read(HMC6352_RAM_READ, HMC6352_RAM_OPMODE);

    return (response & 0x00000003);

}

void HMC6352::setOpMode(int mode, int periodicSetReset, int measurementRate) {

    char opModeByte = mode;

    if (periodicSetReset == 1) {
        opModeByte |= HMC6352_PERIODIC_SR;
    }

    if (measurementRate == 5) {
        opModeByte |= HMC6352_CM_MR_5HZ;
    } else if (measurementRate == 10) {
        opModeByte |= HMC6352_CM_MR_10HZ;
    } else if (measurementRate == 20) {
        opModeByte |= HMC6352_CM_MR_20HZ;
    }

    write(HMC6352_RAM_WRITE, HMC6352_RAM_OPMODE, opModeByte);
    write(HMC6352_EEPROM_WRITE, HMC6352_OPMODE, opModeByte);

    operationMode_ = mode;

}

int HMC6352::getOutputMode(void) {

    return read(HMC6352_RAM_READ, HMC6352_RAM_OUTPUT);

}

void HMC6352::setOutputMode(int mode) {

    write(HMC6352_RAM_WRITE, HMC6352_RAM_OUTPUT, mode);

}

void HMC6352::write(int EepromOrRam, int address, int data) {

    char tx[3];

    tx[0] = EepromOrRam;
    tx[1] = address;
    tx[2] = data;

    i2c_->write((HMC6352_I2C_ADDRESS << 1) & 0xFE, tx, 3);
    wait_ms(1);

}

int HMC6352::read(int EepromOrRam, int address) {

    char tx[2];
    char rx[1];

    tx[0] = EepromOrRam;
    tx[1] = address;

    i2c_->write((HMC6352_I2C_ADDRESS << 1) & 0xFE, tx, 2);
    wait_ms(1);
    i2c_->read((HMC6352_I2C_ADDRESS << 1) | 0x01, rx, 1);
    wait_ms(1);

    return (rx[0]);

}
 

XxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXx HMC6352.h XxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXxXx

/**
 * @author Aaron Berk
 *
 * @section LICENSE
 *
 * Copyright (c) 2010 ARM Limited
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @section DESCRIPTION
 *
 * Honeywell HMC6352 digital compass.
 *
 * Datasheet:
 *
 * http://www.ssec.honeywell.com/magnetic/datasheets/HMC6352.pdf
 */

#ifndef HMC6352_H
#define HMC6352_H

/**
 * Includes
 */
#include "mbed.h"

/**
 * Defines
 */
#define HMC6352_I2C_ADDRESS  0x21 //7-bit address. 0x43 write, 0x42 read.

//Commands.
#define HMC6352_EEPROM_WRITE 0x77
#define HMC6352_EEPROM_READ  0x72
#define HMC6352_RAM_WRITE    0x47
#define HMC6352_RAM_READ     0x67
#define HMC6352_ENTER_SLEEP  0x53
#define HMC6352_EXIT_SLEEP   0x57
#define HMC6352_SET_RESET    0x4F
#define HMC6352_ENTER_CALIB  0x43
#define HMC6352_EXIT_CALIB   0x45
#define HMC6352_SAVE_OPMODE  0x4C
#define HMC6352_GET_DATA     0x41

//EEPROM locations.
#define HMC6352_SLAVE_ADDR   0x00
#define HMC6352_MX_OFF_MSB   0x01
#define HMC6352_MX_OFF_LSB   0x02
#define HMC6352_MY_OFF_MSB   0x03
#define HMC6352_MY_OFF_LSB   0x04
#define HMC6352_TIME_DELAY   0x05
#define HMC6352_SUMMED       0x06
#define HMC6352_SOFT_VER     0x07
#define HMC6352_OPMODE       0x08

//RAM registers.
#define HMC6352_RAM_OPMODE   0x74
#define HMC6352_RAM_OUTPUT   0x4E

#define HMC6352_MX_OFFSET    0x00
#define HMC6352_MY_OFFSET    0x01

#define HMC6352_HEADING_MODE 0x00
#define HMC6352_RAWMAGX_MODE 0x01
#define HMC6352_RAWMAGY_MODE 0x02
#define HMC6352_MAGX_MODE    0x03
#define HMC6352_MAGY_MODE    0x04

//Operational mode register masks.
#define HMC6352_CM_MR_1HZ    0x00
#define HMC6352_CM_MR_5HZ    0x20
#define HMC6352_CM_MR_10HZ   0x40
#define HMC6352_CM_MR_20HZ   0x60

#define HMC6352_PERIODIC_SR  0x10

#define HMC6352_STANDBY      0x00
#define HMC6352_QUERY        0x01
#define HMC6352_CONTINUOUS   0x02

/**
 * Honeywell HMC6352 digital compass.
 */
class HMC6352 {

public:

    /**
     * Constructor.
     *
     * @param sda mbed pin to use for SDA line of I2C interface.
     * @param scl mbed pin to use for SCL line of I2C interface.
     */
    HMC6352(PinName sda, PinName scl);

    /**
     * Sample the device and return the result.
     *
     * @return In heading output mode, the current heading as a number between
     *         0-3599, representing 0-359.9 degrees.
     *         In raw magnetometer X output mode, the raw output of the X-axis
     *         magnetometer.
     *         In raw magnetometer Y mode, the raw output of the Y-axis
     *         magnetometer.
     *         In magnetometer X mode, the corrected output of the X-axis
     *         magnetometer.
     *         In magnetometer Y mode, the corrected output of the Y-axis
     *         magnetometer.
     */
    int sample(void);

    /**
     * Enter into or exit from sleep mode.
     *
     * @param enterOrExit 0x57 -> Exit sleep mode
     *                    0x53 -> Enter
     */
    void setSleepMode(int enterOrExit);

    /**
     * Update bridge offsets.
     *
     * Performs a set/reset immediately.
     */
    void setReset(void);

    /**
     * Enter into or exit from calibration mode.
     *
     * @param enterOrExit 0x45 -> Exit
     *                    0x43 -> Enter
     */
    void setCalibrationMode(int enterOrExit);

    /**
     * Save the current operation mode byte to EEPROM.
     */
    void saveOpMode(void);

    /**
     * Read the memory location on the device which contains the slave address.
     *
     * @return The slave address of the device.
     */
    int getSlaveAddress(void);

    /**
     * Read the current offset for X or Y axis magnetometer.
     *
     * @param axis 0x00 -> X-axis
     *             0x01 -> Y-axis
     * @return The current offset for the axis as a 16-bit number.
     */
    int getOffset(int axis);

    /**
     * Set the offset for X or Y axis magnetometer.
     *
     * @param axis 0x00 -> X-axis
     *             0x01 -> Y-axis
     * @param offset The offset to set for the axis (set to a 16-bit number).
     */
    void setOffset(int axis, int offset);

    /**
     * Get the current time delay.
     *
     * @return The time delay in milliseconds.
     */
    int getTimeDelay(void);

    /**
     * Set the time delay of the device.
     *
     * @param delay The time delay to set in milliseconds (between 0-255);
     */
    void setTimeDelay(int delay);

    /**
     * Get the number of measurements being summed each sample.
     *
     * @return The number of summed measurement.
     */
    int getSumNumber(void);

    /**
     * Set the number of measurements being summed each sample.
     *
     * @param sum The number of measurements to be summed (between 0-16);
     */
    void setSumNumber(int sum);

    /**
     * Get the software version on the device.
     *
     * @return The software version number.
     */
    int getSoftwareVersion(void);

    /**
     * Get the current operation mode.
     *
     * @return 0x00 -> Standby mode
     *         0x01 -> Query mode
     *         0x02 -> Continuous mode
     */
    int getOpMode(void);

    /**
     * Set the operation mode.
     *
     * @param mode 0x00 -> Standby mode
     *             0x01 -> Query mode
     *             0x02 -> Continuous mode
     * @param periodicSetReset 0x00 -> No periodic set/reset
     *                         0x01 -> Periodic set/reset
     * @measurementRate Measurement rate in Hz for continuous rate.
     *                  Possible rates: {1, 5, 10, 20}Hz.
     */
    void setOpMode(int mode, int periodicSetReset, int measurementRate = 0);

    /**
     * Get the current output mode of the device.
     *
     * @return The current output mode.
     */
    int getOutputMode(void);

    /**
     * Set the output mode of the device.
     *
     * @param mode 0x00 -> Heading mode
     *             0x01 -> Raw magnetometer X mode
     *             0x02 -> Raw magnetometer Y mode
     *             0x03 -> Magnetometer X mode
     *             0x04 -> Magnetometer Y mode
     */
    void setOutputMode(int mode);

private:

    I2C* i2c_;
    int  operationMode_;

    /**
     * Write to EEPROM or RAM on the device.
     *
     * @param EepromOrRam 0x77 -> Writing to EEPROM
     *                    0x47 -> Writing to RAM
     * @param address Address to write to.
     * @param data Data to write.
     */
    void write(int EepromOrRam, int address, int data);

    /**
     * Read EEPROM or RAM on the device.
     *
     * @param EepromOrRam 0x72 -> Reading from EEPROM
     *                    0x67 -> Reading from RAM
     * @param address Address to read from.
     * @return The contents of the memory address.
     */
    int read(int EepromOrRam, int address);

};

#endif /* HMC6352_H */
 

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