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/*
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    of this software and associated documentation files (the "Software"), to deal
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    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,
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    THE SOFTWARE.

  * Barometer Sensor (Altimeter) MS5803-01BA of MEAS Switzerland     (www.meas-spec.com).
  * The driver uses I2C mode (sensor PS pin low).
  * Other types of MEAS are compatible but not tested.
  * Written by Raig Kaufer distribute freely!
 */

#include <stdlib.h>
#include "MS5803.h"


/*
 * Sensor operating function according data sheet
 */

/* Send soft reset to the sensor */
void MS5803::MS5803Reset(void) {
    /* transmit out 1 byte reset command */
    ms5803_tx_data[0] = ms5803_reset;
    if ( i2c.write( device_address,  ms5803_tx_data, 1 ) );
    wait_ms(20);
}

/* read the sensor calibration data from rom */
void MS5803::MS5803ReadProm(void) {
    uint8_t i,j;
    for (i=0; i<8; i++) {
        j = i;
        ms5803_tx_data[0] = ms5803_PROMread + (j<<1);
        if ( i2c.write( device_address,  ms5803_tx_data, 1 ) );
        if ( i2c.read( device_address,  ms5803_rx_data, 2 ) );
        C[i]   = ms5803_rx_data[1] + (ms5803_rx_data[0]<<8);
    }
}

/* Start the sensor pressure conversion */
void MS5803::MS5803ConvertD1(void) {
    ms5803_tx_data[0] = ms5803_convD1;
    if ( i2c.write( device_address,  ms5803_tx_data, 1 ) );
}

/* Start the sensor temperature conversion */
void MS5803:: MS5803ConvertD2(void) {
    ms5803_tx_data[0] = ms5803_convD2;
    if ( i2c.write( device_address,  ms5803_tx_data, 1 ) );
}

/* Read the privious started conversion results */
int32_t MS5803::MS5803ReadADC(void) {
    int32_t adc;
    wait_ms(150);
    ms5803_tx_data[0] = ms5803_ADCread;
    if ( i2c.write( device_address,  ms5803_tx_data, 1 ) );
    if ( i2c.read( device_address,  ms5803_rx_data, 3 ) );
    adc = ms5803_rx_data[2] + (ms5803_rx_data[1]<<8) + (ms5803_rx_data[0]<<16);
    return (adc);
}

/* return the results */
float MS5803::MS5803_Pressure (void) {
    return P_MS5803;
}
float MS5803::MS5803_Temperature (void) {
    return T_MS5803;
}

/* Sensor reading and calculation prcedure */
void MS5803::Barometer_MS5803(void) {
    int32_t dT, temp;
    int64_t OFF, SENS, press;

    MS5803Reset();                 // reset the sensor
    MS5803ReadProm();             // read the calibration values
    MS5803ConvertD1();             // start pressure convertion
    D1 = MS5803ReadADC();        // read the pressure value
    MS5803ConvertD2();             // start temperature convertion
    D2 = MS5803ReadADC();         // read the temperature value

    /* calculation according MS5803-01BA data sheet DA5803-01BA_006 */
    dT       = D2 - (C[5]* 256);
    OFF      = (int64_t)C[2] * (1<<16) + ((int64_t)dT * (int64_t)C[4]) / (1<<7);
    SENS     = (int64_t)C[1] * (1<<15) + ((int64_t)dT * (int64_t)C[3]) / (1<<8);

    temp     = 2000 + (dT * C[6]) / (1<<23);
    T_MS5803 = (float) temp / 100.0f;                 // result of temperature in deg C in this var
    press    = (((int64_t)D1 * SENS) / (1<<21) - OFF) / (1<<15);
    P_MS5803 = (float) press / 100.0f;                 // result of pressure in mBar in this var
}