File content as of revision 34:3aa1cbcde59d:

#include "I2C_Sensor.h"

// calculate the 8-Bit write/read I2C-Address from the 7-Bit adress of the device
#define GET_I2C_WRITE_ADDRESS(ADR)  (ADR << 1&0xFE) // ADR & 1111 1110
#define GET_I2C_READ_ADDRESS(ADR)   (ADR << 1|0x01) // ADR | 0000 0001

I2C_Sensor::I2C_Sensor(PinName sda, PinName scl, char i2c_address) :  i2c(sda, scl), local("local")
{
    I2C_Sensor::i2c_address = i2c_address;
    i2c.frequency(400000); // standard speed
    //i2c.frequency(1500000); // ultrafast!
}

void I2C_Sensor::saveCalibrationValues(float values[], int size, char * filename)
{
    FILE *fp = fopen(strcat("/local/", filename), "w");
    for(int i = 0; i < size; i++)
        fprintf(fp, "%f\r\n", values[i]);
    fclose(fp);
}

void I2C_Sensor::loadCalibrationValues(float values[], int size, char * filename)
{
    FILE *fp = fopen(strcat("/local/", filename), "r");
    for(int i = 0; i < size; i++)
        fscanf(fp, "%f", &values[i]);
    fclose(fp);
}

//--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
// ATTENTION!!! the I2C option "repeated" = true is important because otherwise interrupts while bus communications cause crashes (see http://www.i2c-bus.org/repeated-start-condition/)
//--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

char I2C_Sensor::readRegister(char reg)
{
    char value = 0;
    
    i2c.write(i2c_address, &reg, 1, true);
    i2c.read(i2c_address, &value, 1, true);

    return value;
}

void I2C_Sensor::writeRegister(char reg, char data)
{
    char buffer[2] = {reg, data};
    i2c.write(i2c_address, buffer, 2, true);
}

void I2C_Sensor::readMultiRegister(char reg, char* output, int size)
{
    i2c.write (i2c_address, &reg, 1, true); // tell register address of the MSB get the sensor to do slave-transmit subaddress updating.
    i2c.read  (i2c_address, output, size, true); // tell it where to store the data read
}