src/main/drivers/barometer/barometer_bmp280.c

   1 /*
   2  * This file is part of Cleanflight and Betaflight.
   3  *
   4  * Cleanflight and Betaflight are free software. You can redistribute
   5  * this software and/or modify this software under the terms of the
   6  * GNU General Public License as published by the Free Software
   7  * Foundation, either version 3 of the License, or (at your option)
   8  * any later version.
   9  *
  10  * Cleanflight and Betaflight are distributed in the hope that they
  11  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  12  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  13  * See the GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this software.
  17  *
  18  * If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <stdbool.h>
  22 #include <stdint.h>
  23
  24 #include "platform.h"
  25
  26 #include "build/build_config.h"
  27 #include "build/debug.h"
  28
  29 #include "barometer.h"
  30
  31 #include "drivers/bus.h"
  32 #include "drivers/bus_i2c.h"
  33 #include "drivers/bus_i2c_busdev.h"
  34 #include "drivers/bus_spi.h"
  35 #include "drivers/io.h"
  36 #include "drivers/time.h"
  37
  38 #include "barometer_bmp280.h"
  39
  40 // 10 MHz max SPI frequency
  41 #define BMP280_MAX_SPI_CLK_HZ 10000000
  42
  43 #if defined(USE_BARO) && (defined(USE_BARO_BMP280) || defined(USE_BARO_SPI_BMP280))
  44
  45
  46 #define BMP280_I2C_ADDR                      (0x76)
  47 #define BMP280_DEFAULT_CHIP_ID               (0x58)
  48 #define BME280_DEFAULT_CHIP_ID               (0x60)
  49
  50 #define BMP280_CHIP_ID_REG                   (0xD0)  /* Chip ID Register */
  51 #define BMP280_RST_REG                       (0xE0)  /* Softreset Register */
  52 #define BMP280_STAT_REG                      (0xF3)  /* Status Register */
  53 #define BMP280_CTRL_MEAS_REG                 (0xF4)  /* Ctrl Measure Register */
  54 #define BMP280_CONFIG_REG                    (0xF5)  /* Configuration Register */
  55 #define BMP280_PRESSURE_MSB_REG              (0xF7)  /* Pressure MSB Register */
  56 #define BMP280_PRESSURE_LSB_REG              (0xF8)  /* Pressure LSB Register */
  57 #define BMP280_PRESSURE_XLSB_REG             (0xF9)  /* Pressure XLSB Register */
  58 #define BMP280_TEMPERATURE_MSB_REG           (0xFA)  /* Temperature MSB Reg */
  59 #define BMP280_TEMPERATURE_LSB_REG           (0xFB)  /* Temperature LSB Reg */
  60 #define BMP280_TEMPERATURE_XLSB_REG          (0xFC)  /* Temperature XLSB Reg */
  61 #define BMP280_FORCED_MODE                   (0x01)
  62
  63 #define BMP280_TEMPERATURE_CALIB_DIG_T1_LSB_REG             (0x88)
  64 #define BMP280_PRESSURE_TEMPERATURE_CALIB_DATA_LENGTH       (24)
  65 #define BMP280_DATA_FRAME_SIZE               (6)
  66
  67 #define BMP280_OVERSAMP_SKIPPED          (0x00)
  68 #define BMP280_OVERSAMP_1X               (0x01)
  69 #define BMP280_OVERSAMP_2X               (0x02)
  70 #define BMP280_OVERSAMP_4X               (0x03)
  71 #define BMP280_OVERSAMP_8X               (0x04)
  72 #define BMP280_OVERSAMP_16X              (0x05)
  73
  74 // configure pressure and temperature oversampling, forced sampling mode
  75 #define BMP280_PRESSURE_OSR              (BMP280_OVERSAMP_8X)
  76 #define BMP280_TEMPERATURE_OSR           (BMP280_OVERSAMP_1X)
  77 #define BMP280_MODE                      (BMP280_PRESSURE_OSR << 2 | BMP280_TEMPERATURE_OSR << 5 | BMP280_FORCED_MODE)
  78
  79 #define T_INIT_MAX                       (20)
  80 // 20/16 = 1.25 ms
  81 #define T_MEASURE_PER_OSRS_MAX           (37)
  82 // 37/16 = 2.3125 ms
  83 #define T_SETUP_PRESSURE_MAX             (10)
  84 // 10/16 = 0.625 ms
  85
  86 typedef struct bmp280_calib_param_s {
  87     uint16_t dig_T1; /* calibration T1 data */
  88     int16_t dig_T2; /* calibration T2 data */
  89     int16_t dig_T3; /* calibration T3 data */
  90     uint16_t dig_P1; /* calibration P1 data */
  91     int16_t dig_P2; /* calibration P2 data */
  92     int16_t dig_P3; /* calibration P3 data */
  93     int16_t dig_P4; /* calibration P4 data */
  94     int16_t dig_P5; /* calibration P5 data */
  95     int16_t dig_P6; /* calibration P6 data */
  96     int16_t dig_P7; /* calibration P7 data */
  97     int16_t dig_P8; /* calibration P8 data */
  98     int16_t dig_P9; /* calibration P9 data */
  99 } __attribute__((packed)) bmp280_calib_param_t; // packed as we read directly from the device into this structure.
 100
 101 STATIC_ASSERT(sizeof(bmp280_calib_param_t) == BMP280_PRESSURE_TEMPERATURE_CALIB_DATA_LENGTH, bmp280_calibration_structure_incorrectly_packed);
 102
 103 STATIC_UNIT_TESTED int32_t t_fine; /* calibration t_fine data */
 104
 105 static uint8_t bmp280_chip_id = 0;
 106 STATIC_UNIT_TESTED bmp280_calib_param_t bmp280_cal;
 107 // uncompensated pressure and temperature
 108 int32_t bmp280_up = 0;
 109 int32_t bmp280_ut = 0;
 110 static DMA_DATA_ZERO_INIT uint8_t sensor_data[BMP280_DATA_FRAME_SIZE];
 111
 112 static void bmp280StartUT(baroDev_t *baro);
 113 static bool bmp280ReadUT(baroDev_t *baro);
 114 static bool bmp280GetUT(baroDev_t *baro);
 115 static void bmp280StartUP(baroDev_t *baro);
 116 static bool bmp280ReadUP(baroDev_t *baro);
 117 static bool bmp280GetUP(baroDev_t *baro);
 118
 119 STATIC_UNIT_TESTED void bmp280Calculate(int32_t *pressure, int32_t *temperature);
 120
 121 void bmp280BusInit(const extDevice_t *dev)
 122 {
 123 #ifdef USE_BARO_SPI_BMP280
 124     if (dev->bus->busType == BUS_TYPE_SPI) {
 125         IOHi(dev->busType_u.spi.csnPin); // Disable
 126         IOInit(dev->busType_u.spi.csnPin, OWNER_BARO_CS, 0);
 127         IOConfigGPIO(dev->busType_u.spi.csnPin, IOCFG_OUT_PP);
 128         spiSetClkDivisor(dev, spiCalculateDivider(BMP280_MAX_SPI_CLK_HZ));
 129     }
 130 #else
 131     UNUSED(dev);
 132 #endif
 133 }
 134
 135 void bmp280BusDeinit(const extDevice_t *dev)
 136 {
 137 #ifdef USE_BARO_SPI_BMP280
 138     if (dev->bus->busType == BUS_TYPE_SPI) {
 139         spiPreinitByIO(dev->busType_u.spi.csnPin);
 140     }
 141 #else
 142     UNUSED(dev);
 143 #endif
 144 }
 145
 146 #include "drivers/time.h"
 147
 148 bool bmp280Detect(baroDev_t *baro)
 149 {
 150     delay(20);
 151
 152     extDevice_t *dev = &baro->dev;
 153     bool defaultAddressApplied = false;
 154
 155     bmp280BusInit(dev);
 156
 157     if ((dev->bus->busType == BUS_TYPE_I2C) && (dev->busType_u.i2c.address == 0)) {
 158         // Default address for BMP280
 159         dev->busType_u.i2c.address = BMP280_I2C_ADDR;
 160         defaultAddressApplied = true;
 161     }
 162
 163     busReadRegisterBuffer(dev, BMP280_CHIP_ID_REG, &bmp280_chip_id, 1);  /* read Chip Id */
 164
 165     if ((bmp280_chip_id != BMP280_DEFAULT_CHIP_ID) && (bmp280_chip_id != BME280_DEFAULT_CHIP_ID)) {
 166         bmp280BusDeinit(dev);
 167         if (defaultAddressApplied) {
 168             dev->busType_u.i2c.address = 0;
 169         }
 170         return false;
 171     }
 172
 173     busDeviceRegister(dev);
 174
 175     // read calibration
 176     busReadRegisterBuffer(dev, BMP280_TEMPERATURE_CALIB_DIG_T1_LSB_REG, (uint8_t *)&bmp280_cal, sizeof(bmp280_calib_param_t));
 177
 178     // set oversampling + power mode (forced), and start sampling
 179     busWriteRegister(dev, BMP280_CTRL_MEAS_REG, BMP280_MODE);
 180
 181     // these are dummy as temperature is measured as part of pressure
 182     baro->combined_read = true;
 183     baro->ut_delay = 0;
 184     baro->start_ut = bmp280StartUT;
 185     baro->get_ut = bmp280GetUT;
 186     baro->read_ut = bmp280ReadUT;
 187     // only _up part is executed, and gets both temperature and pressure
 188     baro->start_up = bmp280StartUP;
 189     baro->get_up = bmp280GetUP;
 190     baro->read_up = bmp280ReadUP;
 191     baro->up_delay = ((T_INIT_MAX + T_MEASURE_PER_OSRS_MAX * (((1 << BMP280_TEMPERATURE_OSR) >> 1) + ((1 << BMP280_PRESSURE_OSR) >> 1)) + (BMP280_PRESSURE_OSR ? T_SETUP_PRESSURE_MAX : 0) + 15) / 16) * 1000;
 192     baro->calculate = bmp280Calculate;
 193
 194     return true;
 195 }
 196
 197 static void bmp280StartUT(baroDev_t *baro)
 198 {
 199     UNUSED(baro);
 200     // dummy
 201 }
 202
 203 static bool bmp280ReadUT(baroDev_t *baro)
 204 {
 205     UNUSED(baro);
 206     // dummy
 207     return true;
 208 }
 209
 210 static bool bmp280GetUT(baroDev_t *baro)
 211 {
 212     UNUSED(baro);
 213     // dummy
 214     return true;
 215 }
 216
 217 static void bmp280StartUP(baroDev_t *baro)
 218 {
 219     // start measurement
 220     // set oversampling + power mode (forced), and start sampling
 221     busWriteRegisterStart(&baro->dev, BMP280_CTRL_MEAS_REG, BMP280_MODE);
 222 }
 223
 224 static bool bmp280ReadUP(baroDev_t *baro)
 225 {
 226     if (busBusy(&baro->dev, NULL)) {
 227         return false;
 228     }
 229
 230     // read data from sensor
 231     busReadRegisterBufferStart(&baro->dev, BMP280_PRESSURE_MSB_REG, sensor_data, BMP280_DATA_FRAME_SIZE);
 232
 233     return true;
 234 }
 235
 236 static bool bmp280GetUP(baroDev_t *baro)
 237 {
 238     if (busBusy(&baro->dev, NULL)) {
 239         return false;
 240     }
 241
 242     bmp280_up = (int32_t)(sensor_data[0] << 12 | sensor_data[1] << 4 | sensor_data[2] >> 4);
 243     bmp280_ut = (int32_t)(sensor_data[3] << 12 | sensor_data[4] << 4 | sensor_data[5] >> 4);
 244
 245     return true;
 246 }
 247
 248 // Returns temperature in DegC, resolution is 0.01 DegC. Output value of "5123" equals 51.23 DegC
 249 // t_fine carries fine temperature as global value
 250 static int32_t bmp280CompensateTemperature(int32_t adc_T)
 251 {
 252     int32_t var1, var2, T;
 253
 254     var1 = ((((adc_T >> 3) - ((int32_t)bmp280_cal.dig_T1 << 1))) * ((int32_t)bmp280_cal.dig_T2)) >> 11;
 255     var2  = (((((adc_T >> 4) - ((int32_t)bmp280_cal.dig_T1)) * ((adc_T >> 4) - ((int32_t)bmp280_cal.dig_T1))) >> 12) * ((int32_t)bmp280_cal.dig_T3)) >> 14;
 256     t_fine = var1 + var2;
 257     T = (t_fine * 5 + 128) >> 8;
 258
 259     return T;
 260 }
 261
 262 // Returns pressure in Pa as unsigned 32 bit integer in Q24.8 format (24 integer bits and 8 fractional bits).
 263 // Output value of "24674867" represents 24674867/256 = 96386.2 Pa = 963.862 hPa
 264 static uint32_t bmp280CompensatePressure(int32_t adc_P)
 265 {
 266     int64_t var1, var2, p;
 267     var1 = ((int64_t)t_fine) - 128000;
 268     var2 = var1 * var1 * (int64_t)bmp280_cal.dig_P6;
 269     var2 = var2 + ((var1*(int64_t)bmp280_cal.dig_P5) << 17);
 270     var2 = var2 + (((int64_t)bmp280_cal.dig_P4) << 35);
 271     var1 = ((var1 * var1 * (int64_t)bmp280_cal.dig_P3) >> 8) + ((var1 * (int64_t)bmp280_cal.dig_P2) << 12);
 272     var1 = (((((int64_t)1) << 47) + var1)) * ((int64_t)bmp280_cal.dig_P1) >> 33;
 273     if (var1 == 0)
 274         return 0;
 275     p = 1048576 - adc_P;
 276     p = (((p << 31) - var2) * 3125) / var1;
 277     var1 = (((int64_t)bmp280_cal.dig_P9) * (p >> 13) * (p >> 13)) >> 25;
 278     var2 = (((int64_t)bmp280_cal.dig_P8) * p) >> 19;
 279     p = ((p + var1 + var2) >> 8) + (((int64_t)bmp280_cal.dig_P7) << 4);
 280     return (uint32_t)p;
 281 }
 282
 283 STATIC_UNIT_TESTED void bmp280Calculate(int32_t *pressure, int32_t *temperature)
 284 {
 285     // calculate
 286     int32_t t;
 287     uint32_t p;
 288     t = bmp280CompensateTemperature(bmp280_ut);
 289     p = bmp280CompensatePressure(bmp280_up);
 290
 291     if (pressure)
 292         *pressure = (int32_t)(p / 256);
 293     if (temperature)
 294         *temperature = t;
 295 }
 296
 297 #endif