BMP085.h

00001 /**
00002  * Bosch BMP085 Barometer driver
00003  */
00004 
00005 #ifndef BMP085_H
00006 #define BMP085_H
00007 
00008 #include <stdint.h>
00009 #include "mbed.h"
00010 
00011 #define BMP085_ADDR     (0x77<<1)
00012 
00013 typedef enum {
00014     BMP085_CAL_AC1            = 0xAA,
00015     BMP085_CAL_AC2            = 0xAC,
00016     BMP085_CAL_AC3            = 0xAE,
00017     BMP085_CAL_AC4            = 0xB0,
00018     BMP085_CAL_AC5            = 0xB2,
00019     BMP085_CAL_AC6            = 0xB4,
00020     BMP085_CAL_B1             = 0xB6,
00021     BMP085_CAL_B2             = 0xB8,
00022     BMP085_CAL_MB             = 0xBA,
00023     BMP085_CAL_MC             = 0xBC,
00024     BMP085_CAL_MD             = 0xBE,
00025     BMP085_CHIPID             = 0xD0,
00026     BMP085_VERSION            = 0xD1,
00027     BMP085_SOFTRESET          = 0xE0,
00028     BMP085_CTRL               = 0xF4,
00029     BMP085_DATA_TEMP          = 0xF6,
00030     BMP085_DATA_PRESSURE      = 0xF6,
00031     BMP085_CMD_READ_TEMP      = 0x2E,
00032     BMP085_CMD_READ_PRESSURE  = 0x34
00033 } BMP085_Register;
00034 
00035 typedef enum {
00036     BMP085_MODE_ULTRA_LOW_POWER          = 0,
00037     BMP085_MODE_STANDARD                 = 1,
00038     BMP085_MODE_HIGH_RESOLUTION          = 2,
00039     BMP085_MODE_ULTRA_HIGH_RESOLUTION    = 3
00040 } BMP085_Mode;
00041 
00042 typedef enum {
00043     BMP085_IDLE,
00044     BMP085_BUSY,
00045     BMP085_TIMEOUT
00046 } BMP085_State;
00047 
00048 typedef struct {
00049     int16_t  ac1;
00050     int16_t  ac2;
00051     int16_t  ac3;
00052     uint16_t ac4;
00053     uint16_t ac5;
00054     uint16_t ac6;
00055     int16_t  b1;
00056     int16_t  b2;
00057     int16_t  mb;
00058     int16_t  mc;
00059     int16_t  md;
00060 } BMP085_Calibration_Data;
00061 
00062 class BMP085 {
00063 public:
00064     BMP085(PinName sda, PinName scl, BMP085_Mode mode = BMP085_MODE_STANDARD) : _i2c(sda, scl), _mode(mode), _state(BMP085_IDLE) { init(); };
00065     BMP085(I2C & i2c, BMP085_Mode mode = BMP085_MODE_STANDARD) : _i2c(i2c), _mode(mode), _state(BMP085_IDLE) { init(); };
00066     
00067     float get_temperature(void) { return _temperature; };
00068     float get_pressure(void) { return _pressure; };
00069     void measure();
00070     void _callback_handler_timeout();
00071 protected:
00072     void init(void);
00073     uint16_t read_cal_register(BMP085_Register reg);
00074     uint16_t read_uc_temperature(void);
00075     uint32_t read_uc_pressure(void);
00076     I2C _i2c;
00077     BMP085_Mode _mode;
00078     BMP085_State _state;
00079     float _temperature;
00080     float _pressure;
00081     BMP085_Calibration_Data _cal_data;
00082 private:
00083     int transfer(char *tx, int tx_len, char *rx, int rx_len);
00084     int wait(float delay);
00085     
00086     event_callback_t _callback;
00087     void _callback_handler(int event);
00088     uint8_t _tx_buf[2];
00089     uint8_t _rx_buf[3];
00090     
00091     Timer _timeout;
00092 };
00093 
00094 #endif /* BMP085_H */