File content as of revision 0:05db098cf4f8:

/*
 * mbed library program 
 *  Texas Instruments / DRV8830 H-Bridge Voltage-Controlled Motor Driver
 *      http://www.ti.com/product/drv8830
 *
 * Copyright (c) 2014 Kenji Arai / JH1PJL
 *  http://www.page.sannet.ne.jp/kenjia/index.html
 *  http://mbed.org/users/kenjiArai/
 *      Created: August      6th, 2014 
 *      Revised: August     16th, 2014
 *
 * 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    "mbed.h"
#include    "DRV8830.h"

//  motor status
#define DRV8830_FREE            0x00
#define DRV8830_CW              0x01
#define DRV8830_CCW             0x02
#define DRV8830_BREAK           0x03

//  register address
#define DRV8830_CONTROL         0x00
#define DRV8830_FAULT           0x01

//  voltage data
#define DRV8830_V_R48           0x06
#define DRV8830_V_R56           0x07
#define DRV8830_V_R64           0x08
#define DRV8830_V_R72           0x09
    // (no definition from 0.82V to 4.74V)
#define DRV8830_V_4R82          0x3c
#define DRV8830_V_4R90          0x3d
#define DRV8830_V_4R98          0x3e
#define DRV8830_V_5R06          0x3f

#define DRV8830_V_MIN           0x06
#define DRV8830_V_MAX           0x3f
#define DRV8830_V_RANGE         (DRV8830_V_MAX - DRV8830_V_MIN)

//  fault status
#define DRV8830_F_CLEAR         0x80

DRV8830::DRV8830 (PinName p_sda, PinName p_scl, uint8_t addr) : i2c(p_sda, p_scl){
    DRV8830_addr = (char)addr;
}

DRV8830::DRV8830 (I2C& p_i2c, uint8_t addr) : i2c(p_i2c){ 
    DRV8830_addr = (char)addr;
}

void DRV8830::speed(float speed) {
uint8_t direction = 0;
uint8_t pwm_rate = 0;
uint8_t dt[2];

    if (speed == 0.0 ){
        pwm_rate = DRV8830_V_MIN;
        direction = DRV8830_FREE;
    } else if (speed > 0.0){
        pwm_rate = (uint8_t)(DRV8830_V_RANGE * speed) + DRV8830_V_MIN;
        direction = DRV8830_CW;
    } else if (speed < 0.0){
        speed *= -1;
        pwm_rate = (uint8_t)(DRV8830_V_RANGE * speed) + DRV8830_V_MIN;
        direction = DRV8830_CCW;
    }
    if (pwm_rate > DRV8830_V_MAX){
        pwm_rate = DRV8830_V_MAX;
    } else if (pwm_rate < DRV8830_V_MIN){
        pwm_rate = DRV8830_V_MIN;
    }
    dt[0] = DRV8830_CONTROL;
    dt[1] = (pwm_rate << 2) + direction;
    i2c.write((int)DRV8830_addr, (char *)dt, 2);
}

uint8_t DRV8830::status() {
uint8_t dt[2];

    dt[0] = DRV8830_FAULT;
    i2c.write((int)DRV8830ADDR_00, (char *)dt, 1);  // write register address
    i2c.read((int)DRV8830ADDR_00, (char *)dt, 1);   // read register content
    return dt[0];
}

void DRV8830::reset() {
uint8_t dt[2];

    dt[0] = DRV8830_FAULT;
    dt[1] = DRV8830_F_CLEAR;
    i2c.write((int)DRV8830ADDR_00, (char *)dt, 2);
}