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/*
    MPL3115A2 Barometric Pressure and Tempurature Sensor Library
    By: Michael Lange
    Date: March 31, 2014
    License: This code is public domain.
 
    This class wraps the functions of the MPL3115A2 sensor into 
    a usable class that exposes most functions to your project.
    Functions that are not exposed can easily be added using the
    existing functions in this library. Specifically, I did not
    add any funtions to handle FIFO logging or the use of either
    of the pin interrupts. This should not be too difficult to
    add if you need those features.
    
    The motivation here was to get a set of support classes 
    together that supported the chip and could be expanded on.
    With this library you can extract all relevant data from the
    sensor.
    
    Be sure to download the DATASHEET and the App Note AN4519.
    
    This library was created using the mbed NXP LPC11U24. Pins
    p27 and p28 were used for the I2C functions. Be sure to install
    1K pull-up resistors on both lines. Also, if you're not using
    the SparkFun breakout board, be sure to use the right caps on 
    the power pin. If you don't, the jitter can cause problems.
    
    This library was inspired by the similar library available for
    the Arduino written by Nathan Seidle at SparkFun. I copied
    some of the number crunching routines and tried to follow his
    style of coding for the library. That way users of Arduinos
    could step into this library a little easier.
 
 */
 
 
#ifndef MPL3115A2_H
#define MPL3115A2_H

#include "mbed.h"

#include "Altitude.h"               // Our classes to handle compressed data from the sensor.
#include "Temperature.h"
#include "Pressure.h"

#define MPL3115A2_ADDRESS   0xC0    // Shifted 7-bit I2C address for sensor

#define READ_ACK 1                  // For mbed I2C Read method.
#define READ_NAK 0 

#define MAX_DATA_READY_ATTEMPTS 512 // How many times we loop waiting for data before giving up.

//      DEFINE             |REGISTER |RESET |RESET    |TYPE |AUTO-INC      |NAME/COMMENT
//                         |         |      |STBY2ACT |     |ADDRESS       |
#define STATUS              0x00 //  | 0x00 | Yes     | R   | 0x01         | Sensor Status Register (Alias for DR_STATUS or F_STATUS)
#define OUT_P_MSB           0x01 //  | 0x00 | Yes     | R   | 0x02 | 0x01  | Pressure Data Out MSB (Bits 12-19 of 20-bit real-time Pressure sample | Root pointer t oPressure and Tempurature FIFO data)
#define OUT_P_CSB           0x02 //  | 0x00 | Yes     | R   | 0x03         | Pressure Data out CSB (Bits 0-3 of 20-bit real-time Pressure sample)
#define OUT_P_LSB           0x03 //  | 0x00 |         |     | 0x           |
#define OUT_T_MSB           0x04 //  | 0x00 |         |     | 0x           |
#define OUT_T_LSB           0x05 //  | 0x00 |         |     | 0x           |
#define DR_STATUS           0x06 //  | 0x00 |         |     | 0x           |
#define OUT_P_DELTA_MSB     0x07 //  | 0x00 |         |     | 0x           |
#define OUT_P_DELTA_CSB     0x08 //  | 0x00 |         |     | 0x           |
#define OUT_P_DELTA_LSB     0x09 //  | 0x00 |         |     | 0x           |
#define OUT_T_DELTA_MSB     0x0A //  | 0x00 |         |     | 0x           |
#define OUT_T_DELTA_LSB     0x0B //  | 0x00 |         |     | 0x           |
#define WHO_AM_I            0x0C //  | 0xC4 |         |     | 0x           |
#define F_STATUS            0x0D //  | 0x00 |         |     | 0x           |
#define F_DATA              0x0E //  | 0x00 |         |     | 0x           |
#define F_SETUP             0x0F //  | 0x00 |         |     | 0x           |
#define TIME_DLY            0x10 //  | 0x00 |         |     | 0x           |
#define SYSMOD              0x11 //  | 0x00 |         |     | 0x           |
#define INT_SOURCE          0x12 //  | 0x00 |         |     | 0x           |
#define PT_DATA_CFG         0x13 //  | 0x00 |         |     | 0x           |
#define BAR_IN_MSB          0x14 //  | 0xC5 |         |     | 0x           |
#define BAR_IN_LSB          0x15 //  | 0xE7 |         |     | 0x           |
#define P_TGT_MSB           0x16 //  | 0x00 |         |     | 0x           |
#define P_TGT_LSB           0x17 //  | 0x00 |         |     | 0x           |
#define T_TGT               0x18 //  | 0x00 |         |     | 0x           |
#define P_WND_MSB           0x19 //  | 0x00 |         |     | 0x           |
#define P_WND_LSB           0x1A //  | 0x00 |         |     | 0x           |
#define T_WND               0x1B //  | 0x00 |         |     | 0x           |
#define P_MIN_MSB           0x1C //  | 0x00 |         |     | 0x           |
#define P_MIN_CSB           0x1D //  | 0x00 |         |     | 0x           |
#define P_MIN_LSB           0x1E //  | 0x00 |         |     | 0x           |
#define T_MIN_MSB           0x1F //  | 0x00 |         |     | 0x           |
#define T_MIN_LSB           0x20 //  | 0x00 |         |     | 0x           |
#define P_MAX_MSB           0x21 //  | 0x00 |         |     | 0x           |
#define P_MAX_CSB           0x22 //  | 0x00 |         |     | 0x           |
#define P_MAX_LSB           0x23 //  | 0x00 |         |     | 0x           |
#define T_MAX_MSB           0x24 //  | 0x00 |         |     | 0x           |
#define T_MAX_LSB           0x25 //  | 0x00 |         |     | 0x           |
#define CTRL_REG1           0x26 //  | 0x00 |         |     | 0x           |
#define CTRL_REG2           0x27 //  | 0x00 |         |     | 0x           |
#define CTRL_REG3           0x28 //  | 0x00 |         |     | 0x           |
#define CTRL_REG4           0x29 //  | 0x00 |         |     | 0x           |
#define CTRL_REG5           0x2A //  | 0x00 |         |     | 0x           |
#define OFF_P               0x2B //  | 0x00 |         |     | 0x           |
#define OFF_T               0x2C //  | 0x00 |         |     | 0x           |
#define OFF_H               0x2D //  | 0x00 |         |     | 0x           |

//! MPL3115A2 I2C Barometric Pressure and Tempurature Sensor Library
//! This class wraps most of the function in the MPL3115A2 sensor leaving out the FIFO and interrupt system.
class MPL3115A2
{
public:
    //! Constructs an MPL3115A2 object and associates an I2C and optional Serial debug object.
    //! @param *i2c The I2C object to use for the sensor.
    //! @param *pc An optional serial debug connection object.
    MPL3115A2(I2C *i2c, Serial *pc = NULL);

    //! Initializes the sensor, defaulting to Altitude mode. This should be called before using
    //! the sensor for the first time.
    void init();

    //! Queries the value from the WHO_AM_I register (usually equal to 0xC4).
    //! @return The fixed device ID from the sensor.
    char  whoAmI() { return i2cRead(WHO_AM_I); } 
    
    //! Reads Altitude data from the sensor and returns it in the Altitude object passed in. If
    //! no data could be read, the Altitude object is left as is.
    //! @param a A pointer to an Altitude object that will receive the sensor data.
    //! @returns The Altitude pointer that was passed in.
    Altitude* readAltitude(Altitude* a);            
    //! Reads Pressure data from the sensor and returns it in the Pressure object passed in. If
    //! no data could be read, the Pressure object is left as is.
    //! @param a A pointer to a Pressure object that will receive the sensor data.
    //! @returns The Pressure pointer that was passed in.
    Pressure* readPressure(Pressure* p);            
    //! Reads Temperature data from the sensor and returns it in the Temperature object passed in. If
    //! no data could be read, the Temperature object is left as is.
    //! @param a A pointer to an Temperature object that will receive the sensor data.
    //! @returns The Temperature pointer that was passed in.
    Temperature* readTemperature(Temperature* t);
    
    // Use these methods to set the sensor's offsets to increase its accuracy. You can generally
    // find your current altitude with a smart phone or GPS. Same goes for the temperature. For
    // the current pressure where you are, you may need an accurate weather station. Getting the
    // pressure from the web for your area is generally not close enough to help with calibration.
    // You may need to play with the setting to achieve good accuracy. I found the offset steps
    // were not 100% accurate to the datasheet and had to adjust accordingly. 
    
    //! Returns the altitude offset stored in the sensor.
    char offsetAltitude() { return i2cRead(OFF_H); }
    //! Sets the altitude offset stored in the sensor. The allowed offset range is from -128 to 127 meters.
    void setOffsetAltitude(const char offset) { i2cWrite(OFF_H, offset); } 
    //! Returns the pressure offset stored in the sensor.
    char offsetPressure() { return i2cRead(OFF_P); }
    //! Sets the pressure offset stored in the sensor. The allowed offset range is from -128 to 127 where each LSB represents 4 Pa.
    void setOffsetPressure(const char offset) { i2cWrite(OFF_P, offset); }
    //! Returns the temperature offset stored in the sensor.
    char offsetTemperature() { return i2cRead(OFF_T); }
    //! Sets the temperature offset stored in the sensor. The allowed offset range is from -128 to 127 where each LSB represents 0.0625ºC.
    void setOffsetTemperature(const char offset) { i2cWrite(OFF_T, offset); } 
    
    //! Puts the sensor into Standby mode. Required when using methods below.
    void  setModeStandby(); 
    //! Activates the sensor to start taking measurements.
    void  setModeActive();  
    
    //! Puts the sensor into barometric mode, be sure to put the sensor in standby mode first.
    void  setModeBarometer();           
    //! Puts the sensor into altimeter mode, be sure to put the sensor in standby mode first.
    void  setModeAltimeter();           
    //! Sets the number of samples from 1 to 128, be sure to put the sensor in standby mode first.
    void  setOversampleRate(char rate); 
    //! Sets all the event flags, be sure to put the sensor in standby mode first.
    void  enableEventFlags();           

private:
    //! The I2C object we use to communicate with the sensor. It is not part
    //! of the class so that it can be shared with other peripherals on the 
    //! bus.
    I2C *_i2c;          
                        
    //! Set this in the constructor if you want the class to output debug messages.                        
    //! If you need to pair down your code, you can remove this and all the
    //! references to it in the code.
    Serial *_debug;     
 
    //! Debug method that mimics the printf function, but will output nothing if _debug has not
    //! been set. This means you can safely us it in your code and nothing will happen if you don't
    //! assign the _debug object.
    void debugOut(const char * format, ...);

    //! This helper function is used to CLEAR bits. The mask should contain 1s in the position
    //! where the bits need to be cleared. One or more bits can be cleared this way.
    void clearRegisterBit(const char regAddr, const char bitMask);
    //! This helper function is used to SET bits. The mask should contain 1s in the position
    //! where the bits need to be set. One or more bits can be set this way.
    void setRegisterBit(const char regAddr, const char bitMask);

    //! Helper functions to check if data is ready in a register for either temperature or pressure.
    //! The mask passed in determines which register bit to look at.
    int dataReady(const char mask);
    //! Blocks for about 1/2 a second while checking the data ready bit. Returns 0 on sucees.
    //! This function works for both altitude and barometric pressure depending on the mode the sensor is in.
    int pressureDataReady() { return dataReady(0x04); }
    //! Blocks for about 1/2 a second while checking the data ready bit. Returns 0 on sucees.
    int temperatureDataReady() { return dataReady(0x02); }
 
    //! Called to force the sensor to take another sample
    void toggleOneShot();                       
    
    //! Helper functions to read one value from the I2C bus using the sensor's address.
    char i2cRead(char regAddr);
    //! Helper functions to write one value from the I2C bus using the sensor's address.
    void i2cWrite(char regAddr, char value);
};

#endif // MPL3115A2_H