src/main/drivers/barometer/barometer_bmp085.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
  28 #include "barometer.h"
  29
  30 #include "drivers/bus.h"
  31 #include "drivers/bus_i2c.h"
  32 #include "drivers/bus_i2c_busdev.h"
  33 #include "drivers/exti.h"
  34 #include "drivers/io.h"
  35 #include "drivers/nvic.h"
  36 #include "drivers/time.h"
  37
  38 #include "barometer_bmp085.h"
  39
  40 #ifdef USE_BARO
  41
  42 static bool isConversionComplete = false;
  43 static bool isEOCConnected = false;
  44 #define BMP085_DATA_TEMP_SIZE 2
  45 #define BMP085_DATA_PRES_SIZE 3
  46 #define BMP085_DATA_FRAME_SIZE 3
  47 static uint8_t sensor_data[BMP085_DATA_FRAME_SIZE];
  48
  49 #ifdef USE_EXTI
  50 static IO_t eocIO;
  51 static extiCallbackRec_t exti;
  52
  53 static void bmp085ExtiHandler(extiCallbackRec_t* cb)
  54 {
  55     UNUSED(cb);
  56     isConversionComplete = true;
  57 }
  58 #endif
  59
  60 typedef struct {
  61     int16_t ac1;
  62     int16_t ac2;
  63     int16_t ac3;
  64     uint16_t ac4;
  65     uint16_t ac5;
  66     uint16_t ac6;
  67     int16_t b1;
  68     int16_t b2;
  69     int16_t mb;
  70     int16_t mc;
  71     int16_t md;
  72 } bmp085_smd500_calibration_param_t;
  73
  74 typedef struct {
  75     bmp085_smd500_calibration_param_t cal_param;
  76     uint8_t mode;
  77     uint8_t chip_id, ml_version, al_version;
  78     uint8_t dev_addr;
  79     int32_t param_b5;
  80     int16_t oversampling_setting;
  81 } bmp085_t;
  82
  83 #define BMP085_I2C_ADDR         0x77
  84 #define BMP085_CHIP_ID          0x55
  85 #define BOSCH_PRESSURE_BMP085   85
  86 #define BMP085_CHIP_ID_REG      0xD0
  87 #define BMP085_VERSION_REG      0xD1
  88 #define E_SENSOR_NOT_DETECTED   (char) 0
  89 #define BMP085_PROM_START__ADDR 0xaa
  90 #define BMP085_PROM_DATA__LEN   22
  91 #define BMP085_T_MEASURE        0x2E                // temperature measurent
  92 #define BMP085_P_MEASURE        0x34                // pressure measurement
  93 #define BMP085_CTRL_MEAS_REG    0xF4
  94 #define BMP085_ADC_OUT_MSB_REG  0xF6
  95 #define BMP085_ADC_OUT_LSB_REG  0xF7
  96 #define BMP085_CHIP_ID__POS     0
  97 #define BMP085_CHIP_ID__MSK     0xFF
  98 #define BMP085_CHIP_ID__LEN     8
  99 #define BMP085_CHIP_ID__REG     BMP085_CHIP_ID_REG
 100
 101 #define BMP085_ML_VERSION__POS      0
 102 #define BMP085_ML_VERSION__LEN      4
 103 #define BMP085_ML_VERSION__MSK      0x0F
 104 #define BMP085_ML_VERSION__REG      BMP085_VERSION_REG
 105
 106 #define BMP085_AL_VERSION__POS      4
 107 #define BMP085_AL_VERSION__LEN      4
 108 #define BMP085_AL_VERSION__MSK      0xF0
 109 #define BMP085_AL_VERSION__REG      BMP085_VERSION_REG
 110
 111 #define BMP085_GET_BITSLICE(regvar, bitname) (regvar & bitname##__MSK) >> bitname##__POS
 112 #define BMP085_SET_BITSLICE(regvar, bitname, val) (regvar & ~bitname##__MSK) | ((val<<bitname##__POS)&bitname##__MSK)
 113
 114 #define SMD500_PARAM_MG      3038        //calibration parameter
 115 #define SMD500_PARAM_MH     -7357        //calibration parameter
 116 #define SMD500_PARAM_MI      3791        //calibration parameter
 117
 118 STATIC_UNIT_TESTED bmp085_t bmp085;
 119
 120 #define UT_DELAY    6000        // 1.5ms margin according to the spec (4.5ms T conversion time)
 121 #define UP_DELAY    27000       // 6000+21000=27000 1.5ms margin according to the spec (25.5ms P conversion time with OSS=3)
 122
 123 static bool bmp085InitDone = false;
 124 STATIC_UNIT_TESTED uint16_t bmp085_ut;  // static result of temperature measurement
 125 STATIC_UNIT_TESTED uint32_t bmp085_up;  // static result of pressure measurement
 126
 127 static void bmp085ReadCalibrarionParameters(const extDevice_t *dev);
 128 static void bmp085StartUT(baroDev_t *baro);
 129 static bool bmp085ReadUT(baroDev_t *baro);
 130 static bool bmp085GetUT(baroDev_t *baro);
 131 static void bmp085StartUP(baroDev_t *baro);
 132 static bool bmp085ReadUP(baroDev_t *baro);
 133 static bool bmp085GetUP(baroDev_t *baro);
 134 static int32_t bmp085GetTemperature(uint32_t ut);
 135 static int32_t bmp085GetPressure(uint32_t up);
 136 STATIC_UNIT_TESTED void bmp085Calculate(int32_t *pressure, int32_t *temperature);
 137
 138 static bool bmp085TestEOCConnected(baroDev_t *baro, const bmp085Config_t *config);
 139
 140 static IO_t xclrIO = IO_NONE;
 141 #define BMP085_OFF  IOLo(xclrIO);
 142 #define BMP085_ON   IOHi(xclrIO);
 143
 144 static void bmp085InitXclrIO(const bmp085Config_t *config)
 145 {
 146     xclrIO = IOGetByTag(config->xclrTag);
 147     IOInit(xclrIO, OWNER_BARO_XCLR, 0);
 148     IOConfigGPIO(xclrIO, IOCFG_OUT_PP);
 149 }
 150
 151 bool bmp085Detect(const bmp085Config_t *config, baroDev_t *baro)
 152 {
 153     uint8_t data;
 154     bool ack;
 155     bool defaultAddressApplied = false;
 156
 157     if (bmp085InitDone) {
 158         return true;
 159     }
 160
 161     bmp085InitXclrIO(config);
 162     BMP085_ON;   // enable baro
 163
 164 #ifdef USE_EXTI
 165     // EXTI interrupt for barometer EOC
 166
 167     eocIO = IOGetByTag(config->eocTag);
 168     IOInit(eocIO, OWNER_BARO_EOC, 0);
 169     EXTIHandlerInit(&exti, bmp085ExtiHandler);
 170     EXTIConfig(eocIO, &exti, NVIC_PRIO_BARO_EXTI, IOCFG_IN_FLOATING, BETAFLIGHT_EXTI_TRIGGER_RISING);
 171     EXTIEnable(eocIO, true);
 172 #else
 173     UNUSED(config);
 174 #endif
 175
 176     delay(20); // datasheet says 10ms, we'll be careful and do 20.
 177
 178     extDevice_t *dev = &baro->dev;
 179
 180     if ((dev->bus->busType == BUS_TYPE_I2C) && (dev->busType_u.i2c.address == 0)) {
 181         // Default address for BMP085
 182         dev->busType_u.i2c.address = BMP085_I2C_ADDR;
 183         defaultAddressApplied = true;
 184     }
 185
 186     ack = busReadRegisterBuffer(dev, BMP085_CHIP_ID__REG, &data, 1); /* read Chip Id */
 187     if (ack) {
 188         bmp085.chip_id = BMP085_GET_BITSLICE(data, BMP085_CHIP_ID);
 189         bmp085.oversampling_setting = 3;
 190
 191         if (bmp085.chip_id == BMP085_CHIP_ID) { /* get bitslice */
 192             busDeviceRegister(dev);
 193
 194             busReadRegisterBuffer(dev, BMP085_VERSION_REG, &data, 1); /* read Version reg */
 195             bmp085.ml_version = BMP085_GET_BITSLICE(data, BMP085_ML_VERSION); /* get ML Version */
 196             bmp085.al_version = BMP085_GET_BITSLICE(data, BMP085_AL_VERSION); /* get AL Version */
 197             bmp085ReadCalibrarionParameters(dev); /* readout bmp085 calibparam structure */
 198             baro->ut_delay = UT_DELAY;
 199             baro->up_delay = UP_DELAY;
 200             baro->start_ut = bmp085StartUT;
 201             baro->read_ut = bmp085ReadUT;
 202             baro->get_ut = bmp085GetUT;
 203             baro->start_up = bmp085StartUP;
 204             baro->read_up = bmp085ReadUP;
 205             baro->get_up = bmp085GetUP;
 206             baro->calculate = bmp085Calculate;
 207
 208             isEOCConnected = bmp085TestEOCConnected(baro, config);
 209
 210             bmp085InitDone = true;
 211             return true;
 212         }
 213     }
 214
 215 #ifdef USE_EXTI
 216     if (eocIO) {
 217         IORelease(eocIO);
 218         EXTIRelease(eocIO);
 219     }
 220 #endif
 221
 222     BMP085_OFF;
 223
 224     if (defaultAddressApplied) {
 225         dev->busType_u.i2c.address = 0;
 226     }
 227
 228     return false;
 229 }
 230
 231 static int32_t bmp085GetTemperature(uint32_t ut)
 232 {
 233     int32_t temperature;
 234     int32_t x1, x2;
 235
 236     x1 = (((int32_t) ut - (int32_t) bmp085.cal_param.ac6) * (int32_t) bmp085.cal_param.ac5) >> 15;
 237     x2 = ((int32_t) bmp085.cal_param.mc << 11) / (x1 + bmp085.cal_param.md);
 238     bmp085.param_b5 = x1 + x2;
 239     temperature = ((bmp085.param_b5 * 10 + 8) >> 4);  // temperature in 0.01 C (make same as MS5611)
 240
 241     return temperature;
 242 }
 243
 244 static int32_t bmp085GetPressure(uint32_t up)
 245 {
 246     int32_t pressure, x1, x2, x3, b3, b6;
 247     uint32_t b4, b7;
 248
 249     b6 = bmp085.param_b5 - 4000;
 250     // *****calculate B3************
 251     x1 = (b6 * b6) >> 12;
 252     x1 *= bmp085.cal_param.b2;
 253     x1 >>= 11;
 254
 255     x2 = (bmp085.cal_param.ac2 * b6);
 256     x2 >>= 11;
 257
 258     x3 = x1 + x2;
 259
 260     b3 = (((((int32_t) bmp085.cal_param.ac1) * 4 + x3) << bmp085.oversampling_setting) + 2) >> 2;
 261
 262     // *****calculate B4************
 263     x1 = (bmp085.cal_param.ac3 * b6) >> 13;
 264     x2 = (bmp085.cal_param.b1 * ((b6 * b6) >> 12)) >> 16;
 265     x3 = ((x1 + x2) + 2) >> 2;
 266     b4 = (bmp085.cal_param.ac4 * (uint32_t)(x3 + 32768)) >> 15;
 267
 268     b7 = ((uint32_t)(up - b3) * (50000 >> bmp085.oversampling_setting));
 269     if (b7 < 0x80000000) {
 270         pressure = (b7 << 1) / b4;
 271     } else {
 272         pressure = (b7 / b4) << 1;
 273     }
 274
 275     x1 = pressure >> 8;
 276     x1 *= x1;
 277     x1 = (x1 * SMD500_PARAM_MG) >> 16;
 278     x2 = (pressure * SMD500_PARAM_MH) >> 16;
 279     pressure += (x1 + x2 + SMD500_PARAM_MI) >> 4;   // pressure in Pa
 280
 281     return pressure;
 282 }
 283
 284 static void bmp085StartUT(baroDev_t *baro)
 285 {
 286     isConversionComplete = false;
 287
 288     busWriteRegisterStart(&baro->dev, BMP085_CTRL_MEAS_REG, BMP085_T_MEASURE);
 289 }
 290
 291 static bool bmp085ReadUT(baroDev_t *baro)
 292 {
 293     if (busBusy(&baro->dev, NULL)) {
 294         return false;
 295     }
 296
 297     // return old baro value if conversion time exceeds datasheet max when EOC is connected
 298     if (isEOCConnected && !isConversionComplete) {
 299         return false;
 300     }
 301
 302     busReadRegisterBufferStart(&baro->dev, BMP085_ADC_OUT_MSB_REG, sensor_data, BMP085_DATA_TEMP_SIZE);
 303
 304     return true;
 305 }
 306
 307 static bool bmp085GetUT(baroDev_t *baro)
 308 {
 309     if (busBusy(&baro->dev, NULL)) {
 310         return false;
 311     }
 312
 313     bmp085_ut = sensor_data[0] << 8 | sensor_data[1];
 314
 315     return true;
 316 }
 317
 318 static void bmp085StartUP(baroDev_t *baro)
 319 {
 320     uint8_t ctrl_reg_data;
 321
 322     ctrl_reg_data = BMP085_P_MEASURE + (bmp085.oversampling_setting << 6);
 323
 324     isConversionComplete = false;
 325
 326     busWriteRegisterStart(&baro->dev, BMP085_CTRL_MEAS_REG, ctrl_reg_data);
 327 }
 328
 329 static bool bmp085ReadUP(baroDev_t *baro)
 330 {
 331     if (busBusy(&baro->dev, NULL)) {
 332         return false;
 333     }
 334
 335     // return old baro value if conversion time exceeds datasheet max when EOC is connected
 336     if (isEOCConnected && !isConversionComplete) {
 337         return false;
 338     }
 339
 340     busReadRegisterBufferStart(&baro->dev, BMP085_ADC_OUT_MSB_REG, sensor_data, BMP085_DATA_PRES_SIZE);
 341
 342     return true;
 343 }
 344
 345 /** read out up for pressure conversion
 346  depending on the oversampling ratio setting up can be 16 to 19 bit
 347  \return up parameter that represents the uncompensated pressure value
 348  */
 349 static bool bmp085GetUP(baroDev_t *baro)
 350 {
 351     if (busBusy(&baro->dev, NULL)) {
 352         return false;
 353     }
 354
 355     bmp085_up = (uint32_t)(sensor_data[0] << 16 | sensor_data[1] << 8 | sensor_data[2])
 356             >> (8 - bmp085.oversampling_setting);
 357
 358     return true;
 359 }
 360
 361 STATIC_UNIT_TESTED void bmp085Calculate(int32_t *pressure, int32_t *temperature)
 362 {
 363     int32_t temp, press;
 364
 365     temp = bmp085GetTemperature(bmp085_ut);
 366     press = bmp085GetPressure(bmp085_up);
 367     if (pressure)
 368         *pressure = press;
 369     if (temperature)
 370         *temperature = temp;
 371 }
 372
 373 static void bmp085ReadCalibrarionParameters(const extDevice_t *dev)
 374 {
 375     uint8_t data[22];
 376     busReadRegisterBuffer(dev, BMP085_PROM_START__ADDR, data, BMP085_PROM_DATA__LEN);
 377
 378     /*parameters AC1-AC6*/
 379     bmp085.cal_param.ac1 = data[0] << 8 | data[1];
 380     bmp085.cal_param.ac2 = data[2] << 8 | data[3];
 381     bmp085.cal_param.ac3 = data[4] << 8 | data[5];
 382     bmp085.cal_param.ac4 = data[6] << 8 | data[7];
 383     bmp085.cal_param.ac5 = data[8] << 8 | data[9];
 384     bmp085.cal_param.ac6 = data[10] << 8 | data[11];
 385
 386     /*parameters B1,B2*/
 387     bmp085.cal_param.b1 = data[12] << 8 | data[13];
 388     bmp085.cal_param.b2 = data[14] << 8 | data[15];
 389
 390     /*parameters MB,MC,MD*/
 391     bmp085.cal_param.mb = data[16] << 8 | data[17];
 392     bmp085.cal_param.mc = data[18] << 8 | data[19];
 393     bmp085.cal_param.md = data[20] << 8 | data[21];
 394 }
 395
 396 static bool bmp085TestEOCConnected(baroDev_t *baro, const bmp085Config_t *config)
 397 {
 398     UNUSED(config);
 399
 400 #ifdef USE_EXTI
 401     if (!bmp085InitDone && eocIO) {
 402         // EOC should be low at this point. If not, assume EOC is not working
 403         if (IORead(eocIO)) {
 404             return false;
 405         }
 406
 407         bmp085StartUT(baro);
 408         delayMicroseconds(UT_DELAY * 2); // wait twice as long as normal, just to be sure
 409
 410         // conversion should have finished now so check if EOC is high
 411         uint8_t status = IORead(eocIO);
 412         if (status) {
 413             return true;
 414         }
 415     }
 416 #else
 417     UNUSED(baro);
 418 #endif
 419
 420     return false; // assume EOC is not connected
 421 }
 422
 423 #endif /* BARO */