Forked Changes to Pressure sensor
Dependents: WiFiDipCortexSensor
Fork of MPL3115A2 by
MPL3115A2.h@1:a011ae93a350, 2014-04-02 (annotated)
- Committer:
- sophtware
- Date:
- Wed Apr 02 11:12:00 2014 +0000
- Revision:
- 1:a011ae93a350
- Parent:
- 0:beb43bc3d6d4
- Child:
- 2:2ebc9c0d4a54
Some spelling updates.
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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sophtware | 0:beb43bc3d6d4 | 1 | /* |
sophtware | 0:beb43bc3d6d4 | 2 | MPL3115A2 Barometric Pressure and Tempurature Sensor Library |
sophtware | 0:beb43bc3d6d4 | 3 | By: Michael Lange |
sophtware | 0:beb43bc3d6d4 | 4 | Date: March 31, 2014 |
sophtware | 0:beb43bc3d6d4 | 5 | License: This code is public domain. |
sophtware | 0:beb43bc3d6d4 | 6 | |
sophtware | 0:beb43bc3d6d4 | 7 | This class wraps the functions of the MPL3115A2 sensor into |
sophtware | 0:beb43bc3d6d4 | 8 | a usable class that exposes most functions to your project. |
sophtware | 0:beb43bc3d6d4 | 9 | Functions that are not exposed can easily be added using the |
sophtware | 0:beb43bc3d6d4 | 10 | existing functions in this library. Specifically, I did not |
sophtware | 0:beb43bc3d6d4 | 11 | add any funtions to handle FIFO logging or the use of either |
sophtware | 0:beb43bc3d6d4 | 12 | of the pin interrupts. This should not be too difficult to |
sophtware | 0:beb43bc3d6d4 | 13 | add if you need those features. |
sophtware | 0:beb43bc3d6d4 | 14 | |
sophtware | 0:beb43bc3d6d4 | 15 | The motivation here was to get a set of support classes |
sophtware | 0:beb43bc3d6d4 | 16 | together that supported the chip and could be expanded on. |
sophtware | 0:beb43bc3d6d4 | 17 | With this library you can extract all relevant data from the |
sophtware | 0:beb43bc3d6d4 | 18 | sensor. |
sophtware | 0:beb43bc3d6d4 | 19 | |
sophtware | 0:beb43bc3d6d4 | 20 | Be sure to download the DATASHEET and the App Note AN4519. |
sophtware | 0:beb43bc3d6d4 | 21 | |
sophtware | 1:a011ae93a350 | 22 | This library was created using the mbed NXP LPC11U24. Pins |
sophtware | 0:beb43bc3d6d4 | 23 | p27 and p28 were used for the I2C functions. Be sure to install |
sophtware | 0:beb43bc3d6d4 | 24 | 1K pull-up resistors on both lines. Also, if you're not using |
sophtware | 0:beb43bc3d6d4 | 25 | the SparkFun breakout board, be sure to use the right caps on |
sophtware | 0:beb43bc3d6d4 | 26 | the power pin. If you don't, the jitter can cause problems. |
sophtware | 0:beb43bc3d6d4 | 27 | |
sophtware | 0:beb43bc3d6d4 | 28 | This library was inspired by the similar library available for |
sophtware | 0:beb43bc3d6d4 | 29 | the Arduino written by Nathan Seidle at SparkFun. I copied |
sophtware | 0:beb43bc3d6d4 | 30 | some of the number crunching routines and tried to follow his |
sophtware | 0:beb43bc3d6d4 | 31 | style of coding for the library. That way users of Arduinos |
sophtware | 1:a011ae93a350 | 32 | could step into this library a little easier. |
sophtware | 0:beb43bc3d6d4 | 33 | |
sophtware | 0:beb43bc3d6d4 | 34 | */ |
sophtware | 0:beb43bc3d6d4 | 35 | |
sophtware | 0:beb43bc3d6d4 | 36 | |
sophtware | 0:beb43bc3d6d4 | 37 | #ifndef MPL3115A2_H |
sophtware | 0:beb43bc3d6d4 | 38 | #define MPL3115A2_H |
sophtware | 0:beb43bc3d6d4 | 39 | |
sophtware | 0:beb43bc3d6d4 | 40 | #include "mbed.h" |
sophtware | 0:beb43bc3d6d4 | 41 | |
sophtware | 0:beb43bc3d6d4 | 42 | #include "Altitude.h" // Our classes to handle compressed data from the sensor. |
sophtware | 0:beb43bc3d6d4 | 43 | #include "Temperature.h" |
sophtware | 0:beb43bc3d6d4 | 44 | #include "Pressure.h" |
sophtware | 0:beb43bc3d6d4 | 45 | |
sophtware | 0:beb43bc3d6d4 | 46 | #define MPL3115A2_ADDRESS 0xC0 // Shifted 7-bit I2C address for sensor |
sophtware | 0:beb43bc3d6d4 | 47 | |
sophtware | 0:beb43bc3d6d4 | 48 | #define READ_ACK 1 // For mbed I2C Read method. |
sophtware | 0:beb43bc3d6d4 | 49 | #define READ_NAK 0 |
sophtware | 0:beb43bc3d6d4 | 50 | |
sophtware | 0:beb43bc3d6d4 | 51 | #define MAX_DATA_READY_ATTEMPTS 512 // How many times we loop waiting for data before giving up. |
sophtware | 0:beb43bc3d6d4 | 52 | |
sophtware | 0:beb43bc3d6d4 | 53 | // DEFINE |REGISTER |RESET |RESET |TYPE |AUTO-INC |NAME/COMMENT |
sophtware | 0:beb43bc3d6d4 | 54 | // | | |STBY2ACT | |ADDRESS | |
sophtware | 0:beb43bc3d6d4 | 55 | #define STATUS 0x00 // | 0x00 | Yes | R | 0x01 | Sensor Status Register (Alias for DR_STATUS or F_STATUS) |
sophtware | 0:beb43bc3d6d4 | 56 | #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) |
sophtware | 0:beb43bc3d6d4 | 57 | #define OUT_P_CSB 0x02 // | 0x00 | Yes | R | 0x03 | Pressure Data out CSB (Bits 0-3 of 20-bit real-time Pressure sample) |
sophtware | 0:beb43bc3d6d4 | 58 | #define OUT_P_LSB 0x03 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 59 | #define OUT_T_MSB 0x04 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 60 | #define OUT_T_LSB 0x05 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 61 | #define DR_STATUS 0x06 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 62 | #define OUT_P_DELTA_MSB 0x07 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 63 | #define OUT_P_DELTA_CSB 0x08 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 64 | #define OUT_P_DELTA_LSB 0x09 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 65 | #define OUT_T_DELTA_MSB 0x0A // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 66 | #define OUT_T_DELTA_LSB 0x0B // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 67 | #define WHO_AM_I 0x0C // | 0xC4 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 68 | #define F_STATUS 0x0D // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 69 | #define F_DATA 0x0E // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 70 | #define F_SETUP 0x0F // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 71 | #define TIME_DLY 0x10 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 72 | #define SYSMOD 0x11 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 73 | #define INT_SOURCE 0x12 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 74 | #define PT_DATA_CFG 0x13 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 75 | #define BAR_IN_MSB 0x14 // | 0xC5 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 76 | #define BAR_IN_LSB 0x15 // | 0xE7 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 77 | #define P_TGT_MSB 0x16 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 78 | #define P_TGT_LSB 0x17 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 79 | #define T_TGT 0x18 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 80 | #define P_WND_MSB 0x19 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 81 | #define P_WND_LSB 0x1A // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 82 | #define T_WND 0x1B // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 83 | #define P_MIN_MSB 0x1C // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 84 | #define P_MIN_CSB 0x1D // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 85 | #define P_MIN_LSB 0x1E // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 86 | #define T_MIN_MSB 0x1F // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 87 | #define T_MIN_LSB 0x20 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 88 | #define P_MAX_MSB 0x21 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 89 | #define P_MAX_CSB 0x22 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 90 | #define P_MAX_LSB 0x23 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 91 | #define T_MAX_MSB 0x24 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 92 | #define T_MAX_LSB 0x25 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 93 | #define CTRL_REG1 0x26 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 94 | #define CTRL_REG2 0x27 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 95 | #define CTRL_REG3 0x28 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 96 | #define CTRL_REG4 0x29 // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 97 | #define CTRL_REG5 0x2A // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 98 | #define OFF_P 0x2B // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 99 | #define OFF_T 0x2C // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 100 | #define OFF_H 0x2D // | 0x00 | | | 0x | |
sophtware | 0:beb43bc3d6d4 | 101 | |
sophtware | 0:beb43bc3d6d4 | 102 | class MPL3115A2 |
sophtware | 0:beb43bc3d6d4 | 103 | { |
sophtware | 0:beb43bc3d6d4 | 104 | public: |
sophtware | 0:beb43bc3d6d4 | 105 | MPL3115A2(I2C *i2c, Serial *pc = NULL); |
sophtware | 0:beb43bc3d6d4 | 106 | |
sophtware | 0:beb43bc3d6d4 | 107 | // Call this method in main to initialize the sensor. |
sophtware | 0:beb43bc3d6d4 | 108 | void init(); |
sophtware | 0:beb43bc3d6d4 | 109 | |
sophtware | 0:beb43bc3d6d4 | 110 | // Returns the fixed device ID number (usually equal to 0xC4). |
sophtware | 0:beb43bc3d6d4 | 111 | char whoAmI() { return i2cRead(WHO_AM_I); } |
sophtware | 0:beb43bc3d6d4 | 112 | |
sophtware | 0:beb43bc3d6d4 | 113 | Altitude* readAltitude(Altitude* a); // Returns the altitude object with altitude |
sophtware | 0:beb43bc3d6d4 | 114 | Pressure* readPressure(Pressure* p); // Returns the pressure object with barometric pressure |
sophtware | 0:beb43bc3d6d4 | 115 | Temperature* readTemperature(Temperature* t); // Returns the temperature object with temperature |
sophtware | 0:beb43bc3d6d4 | 116 | |
sophtware | 0:beb43bc3d6d4 | 117 | // Use these methods to set the sensor's offsets to increase its accuracy. You can generally |
sophtware | 0:beb43bc3d6d4 | 118 | // find your current altitude with a smart phone or GPS. Same goes for the temperature. For |
sophtware | 0:beb43bc3d6d4 | 119 | // the current pressure where you are, you may need an accurate weather station. Getting the |
sophtware | 0:beb43bc3d6d4 | 120 | // pressure from the web for your area is generally not close enough to help with calibration. |
sophtware | 0:beb43bc3d6d4 | 121 | // You may need to play with the setting to achieve good accuracy. I found the offset steps |
sophtware | 0:beb43bc3d6d4 | 122 | // were not 100% accurate to the datasheet and had to adjust accordingly. |
sophtware | 0:beb43bc3d6d4 | 123 | char offsetAltitude() { return i2cRead(OFF_H); } |
sophtware | 0:beb43bc3d6d4 | 124 | void setOffsetAltitude(const char offset) { i2cWrite(OFF_H, offset); } // -128 to 127 meters |
sophtware | 0:beb43bc3d6d4 | 125 | char offsetPressure() { return i2cRead(OFF_P); } |
sophtware | 0:beb43bc3d6d4 | 126 | void setOffsetPressure(const char offset) { i2cWrite(OFF_P, offset); } // 4 Pa per LSB |
sophtware | 0:beb43bc3d6d4 | 127 | char offsetTemperature() { return i2cRead(OFF_T); } |
sophtware | 0:beb43bc3d6d4 | 128 | void setOffsetTemperature(const char offset) { i2cWrite(OFF_T, offset); } // 0.0625ºC per LSB |
sophtware | 0:beb43bc3d6d4 | 129 | |
sophtware | 0:beb43bc3d6d4 | 130 | void setModeStandby(); // Puts the sensor into Standby mode. Required when using methods below. |
sophtware | 0:beb43bc3d6d4 | 131 | void setModeActive(); // Activates the sensor to start taking measurements. |
sophtware | 0:beb43bc3d6d4 | 132 | |
sophtware | 0:beb43bc3d6d4 | 133 | // When calling any of these methods, be sure to put the sensor in standby mode first. |
sophtware | 1:a011ae93a350 | 134 | void setModeBarometer(); // Puts the sensor into barometric mode |
sophtware | 1:a011ae93a350 | 135 | void setModeAltimeter(); // Puts the sensor into altimeter mode |
sophtware | 1:a011ae93a350 | 136 | void setOversampleRate(char rate); // Sets the number of samples from 1 to 128. |
sophtware | 1:a011ae93a350 | 137 | void enableEventFlags(); // Sets all the event flags. |
sophtware | 0:beb43bc3d6d4 | 138 | |
sophtware | 0:beb43bc3d6d4 | 139 | private: |
sophtware | 0:beb43bc3d6d4 | 140 | I2C *_i2c; // The I2C object we use to communicate with the sensor. It is not part |
sophtware | 0:beb43bc3d6d4 | 141 | // of the class so that it can be shared with other peripherals on the |
sophtware | 0:beb43bc3d6d4 | 142 | // bus. |
sophtware | 0:beb43bc3d6d4 | 143 | Serial *_debug; // Set this in the constructor if you want the class to output debug messages. |
sophtware | 0:beb43bc3d6d4 | 144 | // If you need to pair down your code, you can remove this and all the |
sophtware | 0:beb43bc3d6d4 | 145 | // references to it in the code. |
sophtware | 0:beb43bc3d6d4 | 146 | |
sophtware | 0:beb43bc3d6d4 | 147 | // Debug method that mimics the printf function, but will output nothing if _debug has not |
sophtware | 0:beb43bc3d6d4 | 148 | // been set. This means you can safely us it in your code and nothing will happen if you don't |
sophtware | 0:beb43bc3d6d4 | 149 | // assign the _debug object. |
sophtware | 0:beb43bc3d6d4 | 150 | void debugOut(const char * format, ...); |
sophtware | 0:beb43bc3d6d4 | 151 | |
sophtware | 0:beb43bc3d6d4 | 152 | // These are helper functions to SET or CLEAR bits. The mask should contain 1s in the position |
sophtware | 0:beb43bc3d6d4 | 153 | // where the bits need to be set or cleared. One or more bits can be set or cleared this way. |
sophtware | 0:beb43bc3d6d4 | 154 | void clearRegisterBit(const char regAddr, const char bitMask); |
sophtware | 0:beb43bc3d6d4 | 155 | void setRegisterBit(const char regAddr, const char bitMask); |
sophtware | 0:beb43bc3d6d4 | 156 | |
sophtware | 0:beb43bc3d6d4 | 157 | // Helper functions to check if data is ready in a register for either temperature or pressure. |
sophtware | 0:beb43bc3d6d4 | 158 | // The pressureDataReady function works for both altitude and barometric pressure depending on |
sophtware | 0:beb43bc3d6d4 | 159 | // the mode the sensor is in. |
sophtware | 0:beb43bc3d6d4 | 160 | int dataReady(const char mask); |
sophtware | 0:beb43bc3d6d4 | 161 | int pressureDataReady() { return dataReady(0x04); } |
sophtware | 0:beb43bc3d6d4 | 162 | int temperatureDataReady() { return dataReady(0x02); } |
sophtware | 0:beb43bc3d6d4 | 163 | |
sophtware | 0:beb43bc3d6d4 | 164 | // Called to force the sensor to take another sample |
sophtware | 0:beb43bc3d6d4 | 165 | void toggleOneShot(); |
sophtware | 0:beb43bc3d6d4 | 166 | |
sophtware | 0:beb43bc3d6d4 | 167 | // Helper functions to read and write one value from the I2C bus using the sensor's address. |
sophtware | 0:beb43bc3d6d4 | 168 | char i2cRead(char regAddr); |
sophtware | 0:beb43bc3d6d4 | 169 | void i2cWrite(char regAddr, char value); |
sophtware | 0:beb43bc3d6d4 | 170 | }; |
sophtware | 0:beb43bc3d6d4 | 171 | |
sophtware | 0:beb43bc3d6d4 | 172 | #endif // MPL3115A2_H |