Tasmota/sonoff/xsns_bmp.ino

/*
  xsns_bmp.ino - BMP pressure, temperature and humidity sensor support for Sonoff-Tasmota

  Copyright (C) 2017  Heiko Krupp and Theo Arends

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifdef USE_I2C
#ifdef USE_BMP
/*********************************************************************************************\
 * BMP085, BMP180, BMP280, BME280 - Pressure and Temperature and Humidy (BME280 only)
 *
 * Source: Heiko Krupp and Adafruit Industries
\*********************************************************************************************/

#define BMP_ADDR 0x77

#define BMP180_CHIPID 0x55
#define BMP280_CHIPID 0x58
#define BME280_CHIPID 0x60

#define BMP_REGISTER_CHIPID 0xD0

double bmp_sealevel = 0.0;
uint8_t bmpaddr;
uint8_t bmptype = 0;
char bmpstype[7];

/*********************************************************************************************\
 * BMP085 and BME180
\*********************************************************************************************/

#define BMP180_REG_CONTROL 0xF4
#define BMP180_REG_RESULT 0xF6
#define BMP180_TEMPERATURE 0x2E
#define BMP180_PRESSURE3 0xF4 // Max. oversampling -> OSS = 3

#define BMP180_AC1 0xAA
#define BMP180_AC2 0xAC
#define BMP180_AC3 0xAE
#define BMP180_AC4 0xB0
#define BMP180_AC5 0xB2
#define BMP180_AC6 0xB4
#define BMP180_VB1 0xB6
#define BMP180_VB2 0xB8
#define BMP180_MB 0xBA
#define BMP180_MC 0xBC
#define BMP180_MD 0xBE

#define BMP180_OSS 3

int16_t cal_ac1;
int16_t cal_ac2;
int16_t cal_ac3;
int16_t cal_b1;
int16_t cal_b2;
int16_t cal_mc;
int16_t cal_md;
uint16_t cal_ac4;
uint16_t cal_ac5;
uint16_t cal_ac6;
int32_t bmp180_b5 = 0;

boolean bmp180_calibration()
{
  cal_ac1 = i2c_read16(bmpaddr, BMP180_AC1);
  cal_ac2 = i2c_read16(bmpaddr, BMP180_AC2);
  cal_ac3 = i2c_read16(bmpaddr, BMP180_AC3);
  cal_ac4 = i2c_read16(bmpaddr, BMP180_AC4);
  cal_ac5 = i2c_read16(bmpaddr, BMP180_AC5);
  cal_ac6 = i2c_read16(bmpaddr, BMP180_AC6);
  cal_b1 = i2c_read16(bmpaddr, BMP180_VB1);
  cal_b2 = i2c_read16(bmpaddr, BMP180_VB2);
  cal_mc = i2c_read16(bmpaddr, BMP180_MC);
  cal_md = i2c_read16(bmpaddr, BMP180_MD);

  // Check for Errors in calibration data. Value never is 0x0000 or 0xFFFF
  if (!cal_ac1 | !cal_ac2 | !cal_ac3 | !cal_ac4 | !cal_ac5 | !cal_ac6 | !cal_b1 | !cal_b2 | !cal_mc | !cal_md) {
    return false;
  }

  if ((cal_ac1 == 0xFFFF) |
      (cal_ac2 == 0xFFFF) |
      (cal_ac3 == 0xFFFF) |
      (cal_ac4 == 0xFFFF) |
      (cal_ac5 == 0xFFFF) |
      (cal_ac6 == 0xFFFF) |
      (cal_b1 == 0xFFFF) |
      (cal_b2 == 0xFFFF) |
      (cal_mc == 0xFFFF) |
      (cal_md == 0xFFFF)) {
    return false;
  }
  return true;
}

double bmp180_readTemperature()
{
  i2c_write8(bmpaddr, BMP180_REG_CONTROL, BMP180_TEMPERATURE);
  delay(5); // 5ms conversion time
  int ut = i2c_read16(bmpaddr, BMP180_REG_RESULT);
  int32_t x1 = (ut - (int32_t)cal_ac6) * ((int32_t)cal_ac5) >> 15;
  int32_t x2 = ((int32_t)cal_mc << 11) / (x1 + (int32_t)cal_md);
  bmp180_b5 = x1 + x2;

  return ((bmp180_b5 + 8) >> 4) / 10.0;
}

double bmp180_readPressure()
{
  int32_t p;
  uint8_t msb;
  uint8_t lsb;
  uint8_t xlsb;

  i2c_write8(bmpaddr, BMP180_REG_CONTROL, BMP180_PRESSURE3); // Highest resolution
  delay(2 + (4 << BMP180_OSS));                              // 26ms conversion time at ultra high resolution
  uint32_t up = i2c_read24(bmpaddr, BMP180_REG_RESULT);
  up >>= (8 - BMP180_OSS);

  int32_t b6 = bmp180_b5 - 4000;
  int32_t x1 = ((int32_t)cal_b2 * ((b6 * b6) >> 12)) >> 11;
  int32_t x2 = ((int32_t)cal_ac2 * b6) >> 11;
  int32_t x3 = x1 + x2;
  int32_t b3 = ((((int32_t)cal_ac1 * 4 + x3) << BMP180_OSS) + 2) >> 2;

  x1 = ((int32_t)cal_ac3 * b6) >> 13;
  x2 = ((int32_t)cal_b1 * ((b6 * b6) >> 12)) >> 16;
  x3 = ((x1 + x2) + 2) >> 2;
  uint32_t b4 = ((uint32_t)cal_ac4 * (uint32_t)(x3 + 32768)) >> 15;
  uint32_t b7 = ((uint32_t)up - b3) * (uint32_t)(50000UL >> BMP180_OSS);

  if (b7 < 0x80000000) {
    p = (b7 * 2) / b4;
  }
  else {
    p = (b7 / b4) * 2;
  }

  x1 = (p >> 8) * (p >> 8);
  x1 = (x1 * 3038) >> 16;
  x2 = (-7357 * p) >> 16;

  p += ((x1 + x2 + (int32_t)3791) >> 4);
  return p / 100.0; // convert to mbar
}

double bmp180_calcSealevelPressure(float pAbs, float altitude_meters)
{
  double pressure = pAbs * 100.0;
  return (double)(pressure / pow(1.0 - altitude_meters / 44330, 5.255)) / 100.0;
}

/*********************************************************************************************\
 * BMP280 and BME280
 *
 * Programmer : BMP280/BME280 Datasheet and Adafruit with changes by Theo Arends
\*********************************************************************************************/

#define BME280_REGISTER_CONTROLHUMID 0xF2
#define BME280_REGISTER_CONTROL 0xF4
#define BME280_REGISTER_PRESSUREDATA 0xF7
#define BME280_REGISTER_TEMPDATA 0xFA
#define BME280_REGISTER_HUMIDDATA 0xFD

#define BME280_REGISTER_DIG_T1 0x88
#define BME280_REGISTER_DIG_T2 0x8A
#define BME280_REGISTER_DIG_T3 0x8C
#define BME280_REGISTER_DIG_P1 0x8E
#define BME280_REGISTER_DIG_P2 0x90
#define BME280_REGISTER_DIG_P3 0x92
#define BME280_REGISTER_DIG_P4 0x94
#define BME280_REGISTER_DIG_P5 0x96
#define BME280_REGISTER_DIG_P6 0x98
#define BME280_REGISTER_DIG_P7 0x9A
#define BME280_REGISTER_DIG_P8 0x9C
#define BME280_REGISTER_DIG_P9 0x9E
#define BME280_REGISTER_DIG_H1 0xA1
#define BME280_REGISTER_DIG_H2 0xE1
#define BME280_REGISTER_DIG_H3 0xE3
#define BME280_REGISTER_DIG_H4 0xE4
#define BME280_REGISTER_DIG_H5 0xE5
#define BME280_REGISTER_DIG_H6 0xE7

struct bme280_calib_data
{
  uint16_t dig_T1;
  int16_t dig_T2;
  int16_t dig_T3;
  uint16_t dig_P1;
  int16_t dig_P2;
  int16_t dig_P3;
  int16_t dig_P4;
  int16_t dig_P5;
  int16_t dig_P6;
  int16_t dig_P7;
  int16_t dig_P8;
  int16_t dig_P9;
  uint8_t dig_H1;
  int16_t dig_H2;
  uint8_t dig_H3;
  int16_t dig_H4;
  int16_t dig_H5;
  int8_t dig_H6;
} _bme280_calib;

int32_t t_fine;

boolean bmp280_calibrate()
{
  //  if (i2c_read8(bmpaddr, BMP_REGISTER_CHIPID) != BMP280_CHIPID) return false;

  _bme280_calib.dig_T1 = i2c_read16_LE(bmpaddr, BME280_REGISTER_DIG_T1);
  _bme280_calib.dig_T2 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_T2);
  _bme280_calib.dig_T3 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_T3);
  _bme280_calib.dig_P1 = i2c_read16_LE(bmpaddr, BME280_REGISTER_DIG_P1);
  _bme280_calib.dig_P2 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P2);
  _bme280_calib.dig_P3 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P3);
  _bme280_calib.dig_P4 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P4);
  _bme280_calib.dig_P5 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P5);
  _bme280_calib.dig_P6 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P6);
  _bme280_calib.dig_P7 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P7);
  _bme280_calib.dig_P8 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P8);
  _bme280_calib.dig_P9 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P9);

  //  i2c_write8(bmpaddr, BME280_REGISTER_CONTROL, 0x3F);       // Temp 1x oversampling, Press 16x oversampling, normal mode (Adafruit)
  i2c_write8(bmpaddr, BME280_REGISTER_CONTROL, 0xB7); // 16x oversampling, normal mode (Adafruit)

  return true;
}

boolean bme280_calibrate()
{
  //  if (i2c_read8(bmpaddr, BMP_REGISTER_CHIPID) != BME280_CHIPID) return false;

  _bme280_calib.dig_T1 = i2c_read16_LE(bmpaddr, BME280_REGISTER_DIG_T1);
  _bme280_calib.dig_T2 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_T2);
  _bme280_calib.dig_T3 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_T3);
  _bme280_calib.dig_P1 = i2c_read16_LE(bmpaddr, BME280_REGISTER_DIG_P1);
  _bme280_calib.dig_P2 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P2);
  _bme280_calib.dig_P3 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P3);
  _bme280_calib.dig_P4 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P4);
  _bme280_calib.dig_P5 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P5);
  _bme280_calib.dig_P6 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P6);
  _bme280_calib.dig_P7 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P7);
  _bme280_calib.dig_P8 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P8);
  _bme280_calib.dig_P9 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_P9);
  _bme280_calib.dig_H1 = i2c_read8(bmpaddr, BME280_REGISTER_DIG_H1);
  _bme280_calib.dig_H2 = i2c_readS16_LE(bmpaddr, BME280_REGISTER_DIG_H2);
  _bme280_calib.dig_H3 = i2c_read8(bmpaddr, BME280_REGISTER_DIG_H3);
  _bme280_calib.dig_H4 = (i2c_read8(bmpaddr, BME280_REGISTER_DIG_H4) << 4) | (i2c_read8(bmpaddr, BME280_REGISTER_DIG_H4 + 1) & 0xF);
  _bme280_calib.dig_H5 = (i2c_read8(bmpaddr, BME280_REGISTER_DIG_H5 + 1) << 4) | (i2c_read8(bmpaddr, BME280_REGISTER_DIG_H5) >> 4);
  _bme280_calib.dig_H6 = (int8_t)i2c_read8(bmpaddr, BME280_REGISTER_DIG_H6);

  // Set before CONTROL_meas (DS 5.4.3)
  i2c_write8(bmpaddr, BME280_REGISTER_CONTROLHUMID, 0x05); // 16x oversampling (Adafruit)
  i2c_write8(bmpaddr, BME280_REGISTER_CONTROL, 0xB7);      // 16x oversampling, normal mode (Adafruit)

  return true;
}

double bmp280_readTemperature(void)
{
  int32_t var1;
  int32_t var2;

  int32_t adc_T = i2c_read24(bmpaddr, BME280_REGISTER_TEMPDATA);
  adc_T >>= 4;

  var1 = ((((adc_T >> 3) - ((int32_t)_bme280_calib.dig_T1 << 1))) * ((int32_t)_bme280_calib.dig_T2)) >> 11;
  var2 = (((((adc_T >> 4) - ((int32_t)_bme280_calib.dig_T1)) * ((adc_T >> 4) - ((int32_t)_bme280_calib.dig_T1))) >> 12) *
          ((int32_t)_bme280_calib.dig_T3)) >>
         14;
  t_fine = var1 + var2;
  double T = (t_fine * 5 + 128) >> 8;
  return T / 100.0;
}

double bmp280_readPressure(void)
{
  int64_t var1;
  int64_t var2;
  int64_t p;

  // Must be done first to get the t_fine variable set up
  //  bmp280_readTemperature();

  int32_t adc_P = i2c_read24(bmpaddr, BME280_REGISTER_PRESSUREDATA);
  adc_P >>= 4;

  var1 = ((int64_t)t_fine) - 128000;
  var2 = var1 * var1 * (int64_t)_bme280_calib.dig_P6;
  var2 = var2 + ((var1 * (int64_t)_bme280_calib.dig_P5) << 17);
  var2 = var2 + (((int64_t)_bme280_calib.dig_P4) << 35);
  var1 = ((var1 * var1 * (int64_t)_bme280_calib.dig_P3) >> 8) + ((var1 * (int64_t)_bme280_calib.dig_P2) << 12);
  var1 = (((((int64_t)1) << 47) + var1)) * ((int64_t)_bme280_calib.dig_P1) >> 33;
  if (0 == var1) {
    return 0; // avoid exception caused by division by zero
  }
  p = 1048576 - adc_P;
  p = (((p << 31) - var2) * 3125) / var1;
  var1 = (((int64_t)_bme280_calib.dig_P9) * (p >> 13) * (p >> 13)) >> 25;
  var2 = (((int64_t)_bme280_calib.dig_P8) * p) >> 19;
  p = ((p + var1 + var2) >> 8) + (((int64_t)_bme280_calib.dig_P7) << 4);
  return (double)p / 25600.0;
}

double bme280_readHumidity(void)
{
  int32_t v_x1_u32r;

  // Must be done first to get the t_fine variable set up
  //  bmp280_readTemperature();

  int32_t adc_H = i2c_read16(bmpaddr, BME280_REGISTER_HUMIDDATA);

  v_x1_u32r = (t_fine - ((int32_t)76800));

  v_x1_u32r = (((((adc_H << 14) - (((int32_t)_bme280_calib.dig_H4) << 20) -
                (((int32_t)_bme280_calib.dig_H5) * v_x1_u32r)) +
                 ((int32_t)16384)) >>
                15) *
               (((((((v_x1_u32r * ((int32_t)_bme280_calib.dig_H6)) >> 10) *
                    (((v_x1_u32r * ((int32_t)_bme280_calib.dig_H3)) >> 11) + ((int32_t)32768))) >>
                   10) +
                  ((int32_t)2097152)) *
                     ((int32_t)_bme280_calib.dig_H2) +
                 8192) >>
                14));
  v_x1_u32r = (v_x1_u32r - (((((v_x1_u32r >> 15) * (v_x1_u32r >> 15)) >> 7) *
                             ((int32_t)_bme280_calib.dig_H1)) >>
                            4));
  v_x1_u32r = (v_x1_u32r < 0) ? 0 : v_x1_u32r;
  v_x1_u32r = (v_x1_u32r > 419430400) ? 419430400 : v_x1_u32r;
  double h = (v_x1_u32r >> 12);
  return h / 1024.0;
}

/*********************************************************************************************\
 * BMP
\*********************************************************************************************/

double fastPrecisePow(double a, double b)
{
  // https://martin.ankerl.com/2012/01/25/optimized-approximative-pow-in-c-and-cpp/
  // calculate approximation with fraction of the exponent
  int e = (int)b;
  union {
    double d;
    int x[2];
  } u = { a };
  u.x[1] = (int)((b - e) * (u.x[1] - 1072632447) + 1072632447);
  u.x[0] = 0;
  // exponentiation by squaring with the exponent's integer part
  // double r = u.d makes everything much slower, not sure why
  double r = 1.0;
  while (e) {
    if (e & 1) {
      r *= a;
    }
    a *= a;
    e >>= 1;
  }
  return r * u.d;
}

double bmp_readTemperature(void)
{
  double t = NAN;

  switch (bmptype)
  {
  case BMP180_CHIPID:
    t = bmp180_readTemperature();
    break;
  case BMP280_CHIPID:
  case BME280_CHIPID:
    t = bmp280_readTemperature();
  }
  if (!isnan(t))
  {
    t = convertTemp(t);
    return t;
  }
  return 0;
}

double bmp_readPressure(void)
{
  double pressure = 0.0;

  switch (bmptype) {
  case BMP180_CHIPID:
    pressure = bmp180_readPressure();
  case BMP280_CHIPID:
  case BME280_CHIPID:
    pressure = bmp280_readPressure();
  }
  if (pressure != 0.0) {
//    bmp_sealevel = pressure / pow(1.0 - ((float)sysCfg.altitude / 44330.0), 5.255);  // Adds 8k to the code
    bmp_sealevel = (pressure / fastPrecisePow(1.0 - ((float)sysCfg.altitude / 44330.0), 5.255)) - 21.6;
  }
  return pressure;
}

double bmp_readHumidity(void)
{
  switch (bmptype) {
  case BMP180_CHIPID:
  case BMP280_CHIPID:
    break;
  case BME280_CHIPID:
    return bme280_readHumidity();
  }
  return 0;
}

boolean bmp_detect()
{
  if (bmptype) {
    return true;
  }

  boolean success = false;

  bmpaddr = BMP_ADDR;
  bmptype = i2c_read8(bmpaddr, BMP_REGISTER_CHIPID);
  if (!bmptype) {
    bmpaddr--;
    bmptype = i2c_read8(bmpaddr, BMP_REGISTER_CHIPID);
  }
  strcpy_P(bmpstype, PSTR("BMP"));
  switch (bmptype) {
  case BMP180_CHIPID:
    success = bmp180_calibration();
    strcpy_P(bmpstype, PSTR("BMP180"));
    break;
  case BMP280_CHIPID:
    success = bmp280_calibrate();
    strcpy_P(bmpstype, PSTR("BMP280"));
    break;
  case BME280_CHIPID:
    success = bme280_calibrate();
    strcpy_P(bmpstype, PSTR("BME280"));
  }
  if (success) {
    snprintf_P(log_data, sizeof(log_data), PSTR(D_LOG_I2C "%s " D_FOUND_AT " 0x%x"), bmpstype, bmpaddr);
    addLog(LOG_LEVEL_DEBUG);
  }
  else {
    bmptype = 0;
  }
  return success;
}

/*********************************************************************************************\
 * Presentation
\*********************************************************************************************/

void bmp_mqttPresent(uint8_t *djson)
{
  if (!bmptype) {
    return;
  }

  char stemp1[10];
  char stemp2[10];
  char stemp3[10];
  char stemp4[10];
  char sealevel[40];

  double t = bmp_readTemperature();
  double p = bmp_readPressure();
  double h = bmp_readHumidity();
  dtostrfd(t, sysCfg.flag.temperature_resolution, stemp1);
  dtostrfd(p, sysCfg.flag.pressure_resolution, stemp2);
  dtostrfd(h, sysCfg.flag.humidity_resolution, stemp3);

  dtostrfd(bmp_sealevel, sysCfg.flag.pressure_resolution, stemp4);
  snprintf_P(sealevel, sizeof(sealevel), PSTR(", \"" D_PRESSUREATSEALEVEL "\":%s"), stemp4);
  if (!strcmp(bmpstype, "BME280")) {
    snprintf_P(mqtt_data, sizeof(mqtt_data), PSTR("%s, \"%s\":{\"" D_TEMPERATURE "\":%s, \"" D_HUMIDITY "\":%s, \"" D_PRESSURE "\":%s%s}"),
      mqtt_data, bmpstype, stemp1, stemp3, stemp2, (sysCfg.altitude != 0) ? sealevel : "");
  }
  else {
    snprintf_P(mqtt_data, sizeof(mqtt_data), PSTR("%s, \"%s\":{\"" D_TEMPERATURE "\":%s, \"" D_PRESSURE "\":%s%s}"),
      mqtt_data, bmpstype, stemp1, stemp2, (sysCfg.altitude != 0) ? sealevel : "");
  }
  *djson = 1;
#ifdef USE_DOMOTICZ
  domoticz_sensor3(stemp1, stemp3, stemp2);
#endif // USE_DOMOTICZ
}

#ifdef USE_WEBSERVER
String bmp_webPresent()
{
  String page = "";
  if (bmptype) {
    char stemp[10];
    char sensor[80];

    double t_bmp = bmp_readTemperature();
    double p_bmp = bmp_readPressure();
    double h_bmp = bmp_readHumidity();
    dtostrfi(t_bmp, sysCfg.flag.temperature_resolution, stemp);
    snprintf_P(sensor, sizeof(sensor), HTTP_SNS_TEMP, bmpstype, stemp, tempUnit());
    page += sensor;
    if (!strcmp(bmpstype, "BME280")) {
      dtostrfi(h_bmp, sysCfg.flag.humidity_resolution, stemp);
      snprintf_P(sensor, sizeof(sensor), HTTP_SNS_HUM, bmpstype, stemp);
      page += sensor;
    }
    dtostrfi(p_bmp, sysCfg.flag.pressure_resolution, stemp);
    snprintf_P(sensor, sizeof(sensor), HTTP_SNS_PRESSURE, bmpstype, stemp);
    page += sensor;
    if (sysCfg.altitude != 0) {
      dtostrfi(bmp_sealevel, sysCfg.flag.pressure_resolution, stemp);
      snprintf_P(sensor, sizeof(sensor), HTTP_SNS_PRESSUREATSEALEVEL, bmpstype, stemp);
      page += sensor;
    }
  }
  return page;
}
#endif // USE_WEBSERVER
#endif // USE_BMP
#endif // USE_I2C