MS4525DO.h

00001 
00002 #ifndef MS4525DO_H
00003 #define MS4525DO_H
00004 
00005 #include "mbed.h"
00006 
00007 #define I2C_ADDRESS_MS4525DO    0x28    /**< 7-bit address =0x28. 8-bit is 0x50. Depends on the order code (this is for code "I") */
00008 
00009 /* Register address */
00010 #define ADDR_READ_MR            0x00    /* write to this address to start conversion */
00011 
00012 // MS4525D sensor full scale range and units
00013 const int16_t MS4525FullScaleRange = 1;  // 1 psi
00014 
00015 // MS4525D Sensor type (A or B) comment out the wrong type assignments
00016 // Type A (10% to 90%)
00017 const int16_t MS4525MinScaleCounts = 1638;
00018 const int16_t MS4525FullScaleCounts = 14746;
00019 
00020 const int16_t MS4525Span=MS4525FullScaleCounts-MS4525MinScaleCounts;
00021 
00022 //MS4525D sensor pressure style, differential or otherwise. Comment out the wrong one.
00023 //Differential
00024 const int16_t MS4525ZeroCounts=(MS4525MinScaleCounts+MS4525FullScaleCounts)/2;
00025 
00026 
00027 class MS4525DO
00028 {
00029     public:
00030     // instance methods
00031         // explicit I2C pin names
00032         MS4525DO(PinName sda, PinName sck, char slave_adr = I2C_ADDRESS_MS4525DO);
00033         
00034         // pin names as an object (ideal when sharing the bus)
00035         MS4525DO(I2C &i2c_obj, char slave_adr = I2C_ADDRESS_MS4525DO);
00036     
00037         virtual ~MS4525DO();
00038     
00039     // public functions
00040         void initialize(void);
00041         int measure(void);              // returns status of measurement
00042         float getPSI(void);             // returns the PSI of last measurement
00043         float getTemperature(void);     // returns temperature of last measurement
00044         float getAirSpeed(void);        // calculates and returns the airspeed
00045         int calibrate(void);            // attempts to calibrate and returns a status code
00046          
00047     
00048     private:
00049         I2C         *i2c_p;
00050         I2C         &i2c;
00051         char        address;
00052         char        _status;
00053         float       psi;
00054         float       temperature;
00055         float       airspeed;
00056         uint16_t    P_dat;  // 14 bit pressure data
00057         uint16_t    T_dat;  // 11 bit temperature data
00058         
00059     // private functions
00060         int collect(void);
00061         char fetch_pressure(uint16_t &P_dat, uint16_t &T_dat);
00062           
00063     
00064 };  // end of the class
00065 
00066 
00067 /** airspeed scaling factors; out = (in * Vscale) + offset */
00068 struct airspeed_scale {
00069     float   offset_pa;
00070     float   scale;
00071 };
00072 
00073 #endif