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/**
 ******************************************************************************
 * @file    BME280.cpp
 * @author  Toyomasa Watarai
 * @version V1.0.0
 * @date    11 March 2017
 * @brief   BME280 class implementation
 ******************************************************************************
 * @attention
 *
 * 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.
 */

/*
 *  Modified by Kenji Arai / JH1PJL
 *
 *  http://www.page.sannet.ne.jp/kenjia/index.html
 *  http://mbed.org/users/kenjiArai/
 *      Created:    November  21st, 2018
 *      Revised:    December  29th, 2018
 */

#include "mbed.h"
#include "BME280.h"

BME280::BME280(PinName sda, PinName scl, char slave_adr)
    :
    i2c_p(new I2C(sda, scl)), 
    i2c(*i2c_p),
    address(slave_adr),
    t_fine(0)
{
    initialize();
}

BME280::BME280(I2C &i2c_obj, char slave_adr)
    :
    i2c_p(NULL), 
    i2c(i2c_obj),
    address(slave_adr),
    t_fine(0)
{
    initialize();
}

BME280::~BME280()
{
    if (NULL != i2c_p)
        delete  i2c_p;
}
    
void BME280::initialize()
{
    char cmd[18];
    uint8_t id;

    wait_ms(2);
    id = getID();
    if (id != 0x60){
        if (address == DEFAULT_SLAVE_ADDRESS){
            address = DEFAULT_SLAVE_ADDRESS;
        } else if (address == ANOTHER_SLAVE_ADDRESS){
            address = DEFAULT_SLAVE_ADDRESS;
        }
        id = getID();
        if (id != 0x60){
            cmd[0] = 0xe0;  // reset addr
            cmd[1] = 0xb6;  // reset command
            i2c.write(address, cmd, 2);
            wait_ms(2);
        }
    }

    cmd[0] = 0xf2; // ctrl_hum
    cmd[1] = 0x01; // Humidity oversampling x1
    i2c.write(address, cmd, 2);
 
    cmd[0] = 0xf4; // ctrl_meas
    // Temparature oversampling x1, Pressure oversampling x1, Normal mode
    cmd[1] = 0x27;
    i2c.write(address, cmd, 2);
 
    cmd[0] = 0xf5; // config
    cmd[1] = 0xa0; // Standby 1000ms, Filter off
    i2c.write(address, cmd, 2);
 
    cmd[0] = 0x88; // read dig_T regs
    i2c.write(address, cmd, 1);
    i2c.read(address, cmd, 6);
 
    dig_T1 = (cmd[1] << 8) | cmd[0];
    dig_T2 = (cmd[3] << 8) | cmd[2];
    dig_T3 = (cmd[5] << 8) | cmd[4];
 
    DEBUG_PRINT("dig_T = 0x%x, 0x%x, 0x%x\n", dig_T1, dig_T2, dig_T3);
 
    cmd[0] = 0x8E; // read dig_P regs
    i2c.write(address, cmd, 1);
    i2c.read(address, cmd, 18);
 
    dig_P1 = (cmd[ 1] << 8) | cmd[ 0];
    dig_P2 = (cmd[ 3] << 8) | cmd[ 2];
    dig_P3 = (cmd[ 5] << 8) | cmd[ 4];
    dig_P4 = (cmd[ 7] << 8) | cmd[ 6];
    dig_P5 = (cmd[ 9] << 8) | cmd[ 8];
    dig_P6 = (cmd[11] << 8) | cmd[10];
    dig_P7 = (cmd[13] << 8) | cmd[12];
    dig_P8 = (cmd[15] << 8) | cmd[14];
    dig_P9 = (cmd[17] << 8) | cmd[16];
 
    DEBUG_PRINT(
        "dig_P = 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n",
        dig_P1, dig_P2, dig_P3, dig_P4, dig_P5, dig_P6, dig_P7, dig_P8, dig_P9
    );
 
    cmd[0] = 0xA1; // read dig_H regs
    i2c.write(address, cmd, 1);
    i2c.read(address, cmd, 1);
     cmd[1] = 0xE1; // read dig_H regs
    i2c.write(address, &cmd[1], 1);
    i2c.read(address, &cmd[1], 7);

    dig_H1 = cmd[0];
    dig_H2 = (cmd[2] << 8) | cmd[1];
    dig_H3 = cmd[3];
    dig_H4 = (cmd[4] << 4) | (cmd[5] & 0x0f);
    dig_H5 = (cmd[6] << 4) | ((cmd[5]>>4) & 0x0f);
    dig_H6 = cmd[7];
 
    DEBUG_PRINT("dig_H = 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x\n",
                 dig_H1, dig_H2, dig_H3, dig_H4, dig_H5, dig_H6
    );
}
 
float BME280::getTemperature()
{
    uint32_t temp_raw;
    float tempf;
    char cmd[4];

    if(check_chip() == false){
        return 100.0f;
    }
    cmd[0] = 0xfa; // temp_msb
    i2c.write(address, cmd, 1);
    i2c.read(address, &cmd[1], 3);
 
    temp_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4);
 
    int32_t temp;
 
    temp =
        (((((temp_raw >> 3) - (dig_T1 << 1))) * dig_T2) >> 11) +
        ((((((temp_raw >> 4) - dig_T1) * ((temp_raw >> 4) - dig_T1)) >> 12)
         * dig_T3) >> 14);
 
    t_fine = temp;
    temp = (temp * 5 + 128) >> 8;
    tempf = (float)temp;
 
    return (tempf/100.0f);
}
 
float BME280::getPressure()
{
    uint32_t press_raw;
    float pressf;
    char cmd[4];

    if(check_chip() == false){
        return 2000.0f;
    }

    cmd[0] = 0xf7; // press_msb
    i2c.write(address, cmd, 1);
    i2c.read(address, &cmd[1], 3);
 
    press_raw = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4);
 
    int32_t var1, var2;
    uint32_t press;
 
    var1 = (t_fine >> 1) - 64000;
    var2 = (((var1 >> 2) * (var1 >> 2)) >> 11) * dig_P6;
    var2 = var2 + ((var1 * dig_P5) << 1);
    var2 = (var2 >> 2) + (dig_P4 << 16);
    var1 = (((dig_P3 * (((var1 >> 2)*(var1 >> 2)) >> 13)) >> 3)
             + ((dig_P2 * var1) >> 1)) >> 18;
    var1 = ((32768 + var1) * dig_P1) >> 15;
    if (var1 == 0) {
        return 0;
    }
    press = (((1048576 - press_raw) - (var2 >> 12))) * 3125;
    if(press < 0x80000000) {
        press = (press << 1) / var1;
    } else {
        press = (press / var1) * 2;
    }
    var1 = ((int32_t)dig_P9 * ((int32_t)(((press >> 3)
             * (press >> 3)) >> 13))) >> 12;
    var2 = (((int32_t)(press >> 2)) * (int32_t)dig_P8) >> 13;
    press = (press + ((var1 + var2 + dig_P7) >> 4));
 
    pressf = (float)press;
    return (pressf/100.0f);
}
 
float BME280::getHumidity()
{
    uint32_t hum_raw;
    float humf;
    char cmd[4];
 
    if(check_chip() == false){
        return 0.0f;
    }

    cmd[0] = 0xfd; // hum_msb
    i2c.write(address, cmd, 1);
    i2c.read(address, &cmd[1], 2);
 
    hum_raw = (cmd[1] << 8) | cmd[2];
 
    int32_t v_x1;
 
    v_x1 = t_fine - 76800;
    v_x1 =  (((((hum_raw << 14) -(((int32_t)dig_H4) << 20)
             - (((int32_t)dig_H5) * v_x1)) + ((int32_t)16384)) >> 15)
              * (((((((v_x1 * (int32_t)dig_H6) >> 10)
              * (((v_x1 * ((int32_t)dig_H3)) >> 11) + 32768)) >> 10) + 2097152)
              * (int32_t)dig_H2 + 8192) >> 14));
    v_x1 = (v_x1 - (((((v_x1 >> 15) * (v_x1 >> 15)) >> 7)
              * (int32_t)dig_H1) >> 4));
    v_x1 = (v_x1 < 0 ? 0 : v_x1);
    v_x1 = (v_x1 > 419430400 ? 419430400 : v_x1);
 
    humf = (float)(v_x1 >> 12);
 
    return (humf/1024.0f);
}

//------------------------------------------------------------------------------
// Added functions by JH1PJL
//------------------------------------------------------------------------------
//  Read chip ID
uint8_t BME280::getID(void)
{
    char cmd[4];

    cmd[0] = 0xd0;  // ID addr
    i2c.write(address, cmd, 1, true);
    i2c.read(address, cmd, 2, false);
    return cmd[0];
}

bool BME280::check_chip(void)
{
    uint8_t id;

    id = getID();
    if (id != 0x60){
        if (address == DEFAULT_SLAVE_ADDRESS){
            address = DEFAULT_SLAVE_ADDRESS;
        } else if (address == ANOTHER_SLAVE_ADDRESS){
            address = DEFAULT_SLAVE_ADDRESS;
        }
        id = getID();
        if (id != 0x60){
            return resetChip_by_sw();
        }
    }
    return true;
}

//  Reset the chip by software
bool BME280::resetChip_by_sw(void)
{
    uint8_t id;
    char cmd[4];

    if (address == DEFAULT_SLAVE_ADDRESS){
        ;
    } else if (address == ANOTHER_SLAVE_ADDRESS){
        ;
    } else {
        address = DEFAULT_SLAVE_ADDRESS;
    }
    // 1st try
    cmd[0] = 0xe0;  // reset addr
    cmd[1] = 0xb6;  // reset command
    i2c.write(address, cmd, 2);
    wait_ms(2);
    id = getID();
    if (id == 0x60){
        initialize();
        return true;
    }
    // 2nd retry (reset again and read again)
    cmd[0] = 0xe0;  // reset addr
    cmd[1] = 0xb6;  // reset command
    i2c.write(address, cmd, 2);
    wait_ms(2);
    id = getID();
    if (id == 0x60){
        initialize();
        return true;
    }
    // 3rd retry (reaset again and another chip addr)
    if (address == DEFAULT_SLAVE_ADDRESS){
        address = DEFAULT_SLAVE_ADDRESS;
    } else if (address == ANOTHER_SLAVE_ADDRESS){
        address = DEFAULT_SLAVE_ADDRESS;
    } else {
        return false;
    }
    cmd[0] = 0xe0;  // reset addr
    cmd[1] = 0xb6;  // reset command
    i2c.write(address, cmd, 2);
    wait_ms(2);
    id = getID();
    if (id == 0x60){
        initialize();
        return true;
    }
    return false;
}

// Get compensated data
void BME280::getAll_compensated_data(BME280_Data_TypeDef *dt) { 
    uint32_t raw_data;
    char cmd[8];
 
    // Temperatue
    cmd[0] = 0xfa; // temp_msb
    i2c.write(address, cmd, 1);
    i2c.read(address, &cmd[1], 3);
    raw_data = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4);
    double var1, var2;
    var1 = ((( double)raw_data) /  16384.0 - ((double)dig_T1) / 1024.0) *
             ((double)dig_T2);
    var2 = ((((double)raw_data) / 131072.0 - ((double)dig_T1) / 8192.0) *
            (((double)raw_data) / 131072.0 - ((double)dig_T1) / 8192.0))
            * ((double)dig_T3);
    int32_t t_fine = (int32_t)(var1 + var2);
    dt->temperatue = (var1 + var2) / 5120.0;
    // Pressue
    cmd[0] = 0xf7; // press_msb
    i2c.write(address, cmd, 1);
    i2c.read(address, &cmd[1], 3);
    raw_data = (cmd[1] << 12) | (cmd[2] << 4) | (cmd[3] >> 4);
    double p;
    var1 = ((double)t_fine / 2.0) - 64000.0;
    var2 = var1 * var1 * ((double)dig_P6) / 32768.0;
    var2 = var2 + var1 * ((double)dig_P5) * 2.0;
    var2 = (var2 / 4.0)+(((double)dig_P4) * 65536.0);
    var1 = (((double)dig_P3) * var1 * var1 / 524288.0 +
            ((double)dig_P2) * var1) / 524288.0;
    var1 = (1.0 + var1 / 32768.0)*((double)dig_P1);
    if (var1 == 0.0) {
        dt->pressue = 0.0;
        return; //avoid exception caused by division by zero
    }
    p = 1048576.0 - (double)raw_data;
    p = (p - (var2 / 4096.0)) * 6250.0 / var1;
    var1 = ((double)dig_P9) * p * p / 2147483648.0;
    var2 = p * ((double)dig_P8) / 32768.0;
    p = p + (var1 + var2 + ((double)dig_P7)) / 16.0;
    dt->pressue = p / 100.0;
    // Humidity
    cmd[0] = 0xfd; // hum_msb
    i2c.write(address, cmd, 1);
    i2c.read(address, &cmd[1], 2);
    raw_data = (cmd[1] << 8) | cmd[2];
    double var_H;
    var_H = (((double)t_fine) - 76800.0);
    var_H = (raw_data - (((double)dig_H4) * 64.0 + 
            ((double)dig_H5) / 16384.0 * var_H)) *
            (((double)dig_H2) / 65536.0 * (1.0 + 
            ((double)dig_H6) / 67108864.0 * var_H * 
            (1.0 + ((double)dig_H3) / 67108864.0 * var_H)));
    var_H = var_H * (1.0 - ((double)dig_H1) * var_H / 524288.0);
    if (var_H > 100.0) {
        var_H = 100.0;
    } else if (var_H < 0.0) {
        var_H = 0.0;
    }
    dt->humidity = var_H;
}

#if 0
double calcAltitude(float pressure,float temperature) 
{ 
    // Equation taken from BMP180 datasheet (page 16): 
    //  http://www.adafruit.com/datasheets/BST-BMP180-DS000-09.pdf 
  

    // Note that using the equation from wikipedia can give bad results 
    // at high altitude.  See this thread for more information: 
    //  http://forums.adafruit.com/viewtopic.php?f=22&t=58064 
    /*
    double altitude = (temperature + 273.15) 
      * (pow(MEAN_SEA_LEVEL_PRESSURE/pressure, 0.190294957)-1.0) / 0.0065;
    */ 
    double altitude =
        44330.0 * (1.0 - pow(pressure / MEAN_SEA_LEVEL_PRESSURE, 0.190294957)); 
    return altitude; 
}
#endif