File content as of revision 0:7993a61d8c59:

/* mbed PCF9532 LED Driver Library
 *
 * Copyright (c) 2010, cstyles (http://mbed.org)
 *
 * 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.
 */


#include "PCA9532.h"
#include "mbed.h"

/*
 Constructor, pin names for I2C and the I2C addrss of the device
 */
PCA9532::PCA9532(PinName scl, PinName sda, int addr)
        : _i2c(scl, sda) {

    _i2c.frequency(1000000);

    _addr = addr;

}





/*
 Set the period
 */
int PCA9532::Period (int channel, float period) {

    char reg = 0;
    
    if (channel == 0) {
       reg = PCA9532_REG_PSC0;
    } else if (channel == 1) {
       reg = PCA9532_REG_PSC1;
    } else {
        return (1);
    }

    if (period > 1.0) {
        period = 255;
    } else if ( period < 0.0 ) {
        period = 0;
    } else {
        period = 256 * period;
    }

    _write(reg, period);
    return(0);

}


/*
 Set the duty cycle
 */
int PCA9532::Duty (int channel, float d) {

    char duty = 0;
    char reg = 0;
    
    if (channel == 0) {
       reg = PCA9532_REG_PWM0;
    } else if (channel == 1) {
       reg = PCA9532_REG_PWM1;
    } else {
        return (1);
    }

    if (d > 1.0) {
        duty = 255;
    } else if ( d < 0.0 ) {
        duty = 0;
    } else {
        duty = 256 * d;
    }

    _write(reg, duty);
    return(0);

}

/*
 Set each of the LEDs in this mask to the give mode
 Loop through the mask calling SetLed on each match
 alt_mode specifies the mode of the non-Matches of SetMode
 */
int PCA9532::SetMode (int mask, int mode) {
    if ( (mode < 0) || (mode > 3) ) {
        return(1);
    } else {
        for (int i=0 ; i < 16 ; i++ ) {

            // if this matches, set the LED to the mode
            if (mask & (0x1 << i)) {
                SetLed(i,mode);
            }
        }
    }
    return(0);
}



/*
 led is in the range 0-15
 mode is inthe range 0-3
 */
int PCA9532::SetLed(int led, int mode) {

    int reg = 0;
    int offset = (led % 4);

    printf("\nSetLed(%d,%d)\n", led, mode);

    // makesure mode is within bounds
    if ( (mode < 0) || (mode > 3) ) {
        printf("Error : Invalid mode supplied\n");
        return(1);
    }

    // determine which register this is,
    if (led < 4) {
        reg = PCA9532_REG_LS0;
    } else if ( (led > 3) && (led < 8) ) {
        reg = PCA9532_REG_LS1;
    } else if ( (led > 7) && (led < 12) ) {
        reg = PCA9532_REG_LS2;
    } else if ( (led > 11) && (led < 16) ) {
        reg = PCA9532_REG_LS3;
    } else {
        return(1);
    }

    // read the current status of the register
    char regval = _read(reg);

    // clear the two bit slice at the calculated offset
    regval &= ~(0x3 << (2 * offset));

    // now OR in the mode, shifted by 2*offset
    regval |= (mode << (2 * offset));

    // write the new value back
    _write(reg, regval);

    return(0);
}



// private functions for low level IO

void PCA9532::_write(int reg, int data) {
    char args[2];
    args[0] = reg;
    args[1] = data;
    _i2c.write(_addr, args,2);
}

int PCA9532::_read(int reg) {
    char args[2];
    args[0] = reg;
    _i2c.write(_addr, args, 1);
    _i2c.read(_addr, args, 1);
    return(args[0]);
}