BMP280.h

00001 /*******************************************************************************
00002 * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
00003 *
00004 * Permission is hereby granted, free of charge, to any person obtaining a
00005 * copy of this software and associated documentation files (the "Software"),
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00009 * Software is furnished to do so, subject to the following conditions:
00010 *
00011 * The above copyright notice and this permission notice shall be included
00012 * in all copies or substantial portions of the Software.
00013 *
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00015 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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00021 *
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00024 * Products, Inc. Branding Policy.
00025 *
00026 * The mere transfer of this software does not imply any licenses
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00032 /**
00033  * Bosch BMP280 Digital Pressure Sensor
00034  *
00035  * @code
00036  * #include <stdio.h>
00037  * #include "mbed.h"
00038  * #include "xxx.h"
00039  *
00040  * I2C i2c(I2C_SDA, I2C_SCL);
00041  * xxx xxx(&i2c);
00042  *
00043  * int main(void) {
00044  *     printf("Initialized xxx\n");
00045  *     while(1) {
00046  *         if (xxx.init() != 0) {
00047  *             printf("Error communicating with xxx\n");
00048  *         } else {
00049  *             printf("Initialized xxx\n");
00050  *             break;
00051  *         }
00052  *         wait(1);
00053  *     }
00054  *
00055  *     while(1) {
00056  *         printf("");
00057  *         wait(1);
00058  *     }
00059  * }
00060  * @endcode
00061  */
00062 
00063 #ifndef BMP280_H_
00064 #define BMP280_H_
00065 
00066 #include "mbed.h"
00067 
00068 #define BMP280_READID       (0x58)
00069 
00070 #define BMP280_TEMP_XLSB    (0xFC)
00071 #define BMP280_TEMP_LSB     (0xFB)
00072 #define BMP280_TEMP_MSB     (0xFA)
00073 
00074 #define BMP280_PRESS_XLSB   (0xF9)
00075 #define BMP280_PRESS_LSB    (0xF8)
00076 #define BMP280_PRESS_MSB    (0xF7)
00077 
00078 #define BMP280_CONFIG       (0xF5)
00079 #define BMP280_CTRL_MEAS    (0xF4)
00080 #define BMP280_STATUS       (0xF3)
00081 #define BMP280_RESET        (0xE0)
00082 #define BMP280_ID           (0xD0)
00083 
00084 // calib25-calib00: 0xA1-0x88
00085 #define BMP280_CALIB25      (0xA1) // Beginning address
00086 #define BMP280_CALIB00      (0x88) // Ending address
00087 
00088 #define BMP280_REGISTER_CHIPID    (0xD0)
00089 #define BMP280_REGISTER_VERSION   (0xD1)
00090 #define BMP280_REGISTER_SOFTRESET (0xE0)
00091 
00092 #define BMP280_REGISTER_CAL26     (0xE1) // R calibration stored in 0xE1-0xF0
00093 
00094 #define BMP280_REGISTER_CONTROL      (0xF4)
00095 #define BMP280_REGISTER_CONFIG       (0xF5)
00096 #define BMP280_REGISTER_PRESSUREDATA (0xF7)
00097 #define BMP280_REGISTER_TEMPDATA     (0xFA)
00098 
00099 /**
00100  * @brief Bosch BMP280 Digital Pressure Sensor
00101  */
00102 class BMP280 {
00103 
00104 public:
00105   /**
00106    * BMP280 constructor.
00107    *
00108    * @param sda mbed pin to use for SDA line of I2C interface.
00109    * @param scl mbed pin to use for SCL line of I2C interface.
00110    * @param slaveAddress Slave Address of the device.
00111    */
00112   BMP280(PinName sda, PinName scl, int slaveAddress);
00113 
00114   /**
00115    * BMP280 constructor.
00116    *
00117    * @param i2c I2C object to use.
00118    * @param slaveAddress Slave Address of the device.
00119    */
00120   BMP280(I2C *i2c, int slaveAddress);
00121 
00122   char loggingEnabled;
00123   char loggingSampleRate;
00124 
00125   /**
00126   * Write a device register
00127   */
00128   int writeReg(char reg, char value);
00129   /**
00130   * Read a device register
00131   */
00132   int readReg(char reg, char *value);
00133 
00134   /// @brief TEMP_XLSB (0xFC)
00135   char bmp280_temp_xlsb; // Lower 4-bits are all 0's
00136 
00137   /// @brief TEMP_LSB (0xFB)
00138   char bmp280_temp_lsb;
00139 
00140   /// @brief TEMP_MSB (0xFA)
00141   char bmp280_temp_msb;
00142 
00143   /// @brief PRESS_XLSB (0xF9)
00144   char bmp280_press_xlsb; // Lower 4-bits are all 0's
00145 
00146   /// @brief PRESS_LSB (0xF8)
00147   char bmp280_press_lsb;
00148 
00149   /// @brief PRESS_MSB (0xF7)
00150   char bmp280_press_msb;
00151 
00152   /// @brief CONFIG_REG (0xF5)
00153   union bmp280_config_reg {
00154     char all;
00155     struct {
00156       char spi3w_en : 1;
00157       char reserved : 1;
00158       char filter : 3;
00159       char t_sb : 3;
00160     } bit;
00161   } bmp280_config;
00162 
00163   /// @brief CTRL_MEAS (0xF4)
00164   union bmp280_ctrl_meas {
00165     char all;
00166     struct {
00167       char mode : 2;
00168       char osrs_p : 3;
00169       char osrs_t : 3;
00170     } bit;
00171   } bmp280_ctrl_meas;
00172 
00173   /// @brief STATUS (0xF3)
00174   union bmp280_status {
00175     char all;
00176     struct {
00177       char im_update : 1;
00178       char reserved1 : 2;
00179       char measuring : 1;
00180       char reserved2 : 4;
00181     } bit;
00182   } bmp280_status;
00183 
00184   /// @brief  RESET (0xE0)
00185   char bmp280_reset;
00186 
00187   /// @brief  ID (0xD0)
00188   char bmp280_id;
00189 
00190   typedef enum {
00191     SKIPPED_P = 0,
00192     OVERSAMPLING_X1_P = 1,
00193     OVERSAMPLING_X2_P = 2,
00194     OVERSAMPLING_X4_P = 3,
00195     OVERSAMPLING_X8_P = 4,
00196     OVERSAMPLING_X16_P = 5
00197   } bmp280_osrs_P_t;
00198 
00199   typedef enum {
00200     SKIPPED_T = 0,
00201     OVERSAMPLING_X1_T = 1,
00202     OVERSAMPLING_X2_T = 2,
00203     OVERSAMPLING_X4_T = 3,
00204     OVERSAMPLING_X8_T = 4,
00205     OVERSAMPLING_X16_T = 5
00206   } bmp280_osrs_T_t;
00207 
00208   typedef enum {
00209     FILT_OFF = 1,
00210     FILT_2 = 2,
00211     FILT_3 = 4,
00212     FILT_4 = 8,
00213     FILT_5 = 16
00214   } bmp280_FILT_t;
00215 
00216   typedef enum {
00217     SLEEP_MODE = 0,
00218     FORCED_MODE = 1,
00219     NORMAL_MODE = 3
00220   } bmp280_MODE_t;
00221 
00222   typedef enum {
00223     T_0_5 = 0,
00224     T_62_5 = 1,
00225     T_125 = 2,
00226     T_250 = 3,
00227     T_500 = 4,
00228     T_1000 = 5,
00229     T_2000 = 6,
00230     T_4000 = 7
00231   } bmp280_TSB_t;
00232 
00233   /// @brief calib25... calib00  (0xA1...0x88)
00234   char bmp280_Calib[26];
00235 
00236   uint16_t dig_T1;
00237   int16_t dig_T2;
00238   int16_t dig_T3;
00239 
00240   uint16_t dig_P1;
00241   int16_t dig_P2;
00242   int16_t dig_P3;
00243   int16_t dig_P4;
00244   int16_t dig_P5;
00245   int16_t dig_P6;
00246   int16_t dig_P7;
00247   int16_t dig_P8;
00248   int16_t dig_P9;
00249 
00250   int32_t t_fine; // This is calculated int the temperature to be used by the
00251                   // pressure
00252 
00253   int32_t bmp280_rawPress;
00254   int32_t bmp280_rawTemp;
00255 
00256   float Temp_degC; //  Deg C.
00257   float Press_Pa;  //   Pascal.
00258 
00259   /**
00260    * BMP280 constructor.
00261    *
00262    * @param sda mbed pin to use for SDA line of I2C interface.
00263    * @param scl mbed pin to use for SCL line of I2C interface.
00264    */
00265   BMP280(PinName sda, PinName scl);
00266 
00267   /**
00268    * BMP280 constructor.
00269    *
00270    * @param i2c I2C object to use.
00271    */
00272   BMP280(I2C *i2c);
00273 
00274   /**
00275    * BMP280 destructor.
00276    */
00277   ~BMP280(void);
00278 
00279   // Function Prototypes
00280 
00281   /**
00282   * @brief This initializes the BMP280 
00283   * @brief The BMP280 has 2 modes. FORCED mode and  NORMAL mode.  FORCED Mode gives more
00284   * @brief control to the processor as the processor sends out the Mode to initiate a conversion
00285   * @brief and a data is sent out then. NORMAL mode is initialized once and it just runs and sends
00286   * @brief out data at a programmed timed interval.  (In this example the main() will set this to Normal
00287   * @brief function)
00288   * @param Osrs_p- Pressure oversampling
00289   * @param Osrs_t-  Temperature oversampling
00290   * @param Filter-  Filter Settings
00291   * @param Mode-    Power Modes
00292   * @param T_sb-    Standby time (used with Normal mode)
00293   * @param dig_T1, dig_T2, dig_T3-  Coeffs used for temp conversion - GLOBAL variables (output)
00294   * @param dig_P1, ....  , dig_P9-  Coeffs used for press conversion - GLOBAL variables (output)
00295   * @returns  0-if no error.  A non-zero value indicates an error.
00296   */
00297   int init(bmp280_osrs_P_t Osrs_p, bmp280_osrs_T_t Osrs_t, bmp280_FILT_t Filter,
00298            bmp280_MODE_t Mode, bmp280_TSB_t T_sb);
00299 
00300   /**
00301    * @brief The BMP280 has 2 modes. FORCED mode and  NORMAL mode.  FORCED Mode
00302    * gives more
00303    * @brief control to the processor as the processor sends out the Mode to
00304    * initiate a conversion
00305    * @brief and a data is sent out then. NORMAL mode is initialized once and it
00306    * just runs and sends
00307    * @brief out data at a programmed timed interval.  (In this example the
00308    * main() will set this to Normal
00309    * @brief function)
00310    * @param *Temp_degC - Pointer to temperature (result in deg C)
00311    * @param *Press_Pa - Pointer to pressure (resul in Pascal)
00312    * @returns 0-if no error.  A non-zero value indicates an error.
00313    */
00314   int ReadCompData(float *Temp_degC, float *Press_Pa);
00315 
00316   /**
00317    *  @brief This function allows writing to a register.
00318    *  @param reg- Address of the register to write to
00319    *  @param value- Data written to the register
00320    *  @returns 0-if no error.  A non-zero value indicates an error.
00321    */
00322   int reg_write(char reg, char value);
00323 
00324   /**
00325    * @brief This function allows writing to a register.
00326    * @params reg- Address of the register to read from (input)
00327    * @params *value- Pointer to the value read from the register (output)
00328    * @returns 0-if no error.  A non-zero value indicates an error.
00329    */
00330   int reg_read(char reg, char *value, char number);
00331 
00332   /**
00333    * @brief Performs a soft reset on the BMP280
00334    * @param none
00335    * @returns none
00336    */
00337   void Reset(void);
00338 
00339   /**
00340    * @brief Detects if the BMP280 is present
00341    * @param none
00342    * @returns 1 for found, 0 for not found, -1 for comm error
00343    */
00344   int Detect(void);
00345 
00346   /**
00347    * @brief Performs calculations on the raw temperature data to convert to
00348    * @brief temperature in deg C, based on Bosch's algorithm
00349    * @param Raw Temp ADC value, Global dig_T1, dig_T2, dig_T3
00350    * @returns The Temperature in deg C
00351    */
00352   float compensate_T_float(int32_t adc_T); // returned value Deg C.
00353 
00354   /**
00355     * @brief Performs calculations on the raw pressure data to convert to
00356     * @brief pressure in Pascal, based on Bosch's algorithm
00357     * @param adc_P Raw Press ADC value, Global dig_P1, dig_P2,..., dig_P9
00358     * @returns The Pressure in Pascals
00359     */
00360   float compensate_P_float(int32_t adc_P); //  returned value Pascal.
00361 
00362   /**
00363    * @brief Puts the BMP280 in low power Sleep mode
00364    * @param none
00365    * @returns 0 if no errors, -1 if error.
00366    */
00367   int Sleep(void);
00368 
00369   /**
00370    * @brief This reads the raw BMP280 data
00371    * @param *bmp280_rawData- array of raw output data
00372    * @returns 0-if no error.  A non-zero value indicates an error.
00373    *
00374    */
00375   int ReadCompDataRaw(char *bmp280_rawData);
00376   /**
00377    * @brief This reads the raw BMP280 data uses the Bosch algorithm to get the
00378    * data
00379    * @brief in float, then the float gets converted to an String
00380    * @param *bmp280_rawData- array of raw output data
00381    * @returns 0-if no error.  A non-zero value indicates an error.
00382    *
00383    */
00384   int ReadCompDataRaw2(char *bmp280_rawData);
00385   /**
00386    * @brief This converts the raw BMP280 data to couble based on Bosch's
00387    * algorithm
00388    * @param *bmp280_rawData- array of raw input data
00389    * @param *Temp_degC- pointer to output, Temp value in deg C
00390    * @param *Press_Pa- pointer to output, Press value in Pascals
00391    * @returns 0-if no error.  A non-zero value indicates an error.
00392    *
00393    */
00394   void ToFloat(char *bmp280_rawData, float *Temp_degC, float *Press_Pa);
00395   /**
00396    * @brief converts to Farenhite from Centigrade
00397    * @param temperature in Centigrade
00398    * @returns temperature value in Farenhite
00399    */
00400   float ToFahrenheit(float temperature);
00401 
00402   /**
00403    * @brief Reads a unique ID from the register
00404    * @param none
00405    * @returns The correct id value which is 0x58
00406    */
00407   int ReadId(void);
00408 
00409 private:
00410   /// I2C pointer
00411   I2C *i2c;
00412   /// Is this object the owner of the I2C object
00413   bool isOwner;
00414   /// Device slave address
00415   int slaveAddress;
00416 };
00417 
00418 #endif // BMP280_H_