1 /* 2 * Author: William Penner <william.penner (at) intel.com> 3 * Copyright (c) 2014 Intel Corporation. 4 * 5 * Permission is hereby granted, free of charge, to any person obtaining a copy 6 * of this software and associated documentation files (the "Software"), to deal 7 * in the Software without restriction, including without limitation the rights 8 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 9 * copies of the Software, and to permit persons to whom the Software is 10 * furnished to do so, subject to the following conditions: 11 * 12 * The above copyright notice and this permission notice shall be included in 13 * all copies or substantial portions of the Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 21 * THE SOFTWARE. 22 */ 23 24 #pragma once 25 26 #include <string> 27 #include <mraa/i2c.hpp> 28 #include <math.h> 29 30 #define MPL3115A2_NAME "mpl3115a2" 31 32 #define MPL3115A2_I2C_ADDRESS 0x60 33 #define MPL3115A2_DEVICE_ID 0xc4 34 35 #define MPL3115A2_STATUS 0x00 36 #define MPL3115A2_OUT_PRESS 0x01 /* MSB first, 20 bit */ 37 #define MPL3115A2_OUT_TEMP 0x04 /* MSB first, 12 bit */ 38 #define MPL3115A2_WHO_AM_I 0x0c 39 #define MPL3115A2_PT_DATA_CFG 0x13 40 #define MPL3115A2_P_MIN 0x1C 41 #define MPL3115A2_T_MIN 0x1F 42 #define MPL3115A2_P_MAX 0x21 43 #define MPL3115A2_T_MAX 0x24 44 #define MPL3115A2_CTRL_REG1 0x26 45 46 // CTRL_REG1 47 #define MPL3115A2_CTRL_SBYB 0x01 /* Standby (not) */ 48 #define MPL3115A2_CTRL_OST 0x02 /* One-shot trigger */ 49 #define MPL3115A2_CTRL_RESET 0x04 /* RESET device */ 50 #define MPL3115A2_CTRL_ALT_MODE 0x80 /* Altitude mode */ 51 52 #define MPL3115A2_SETOVERSAMPLE(a) ((a & 7) << 3) 53 #define MPL3115A2_GETOVERSAMPLE(a) ((a >> 3) & 7) 54 #define MPL3115A2_MAXOVERSAMPLE 7 55 56 namespace upm { 57 58 /** 59 * @brief MPL3115A2 Atmospheric Pressure Sensor library 60 * @defgroup mpl3115a2 libupm-mpl3115a2 61 * @ingroup freescale i2c pressure 62 */ 63 /** 64 * @library mpl3115a2 65 * @sensor mpl3115a2 66 * @comname MPL3115A2 Atmospheric Pressure Sensor 67 * @type pressure 68 * @man freescale 69 * @web http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MPL3115A2 70 * @con i2c 71 * 72 * @brief API for the MPL3115A2 Atmospheric Pressure Sensor 73 * 74 * Freescale Semiconductor* [MPL3115A2] 75 * (http://cache.freescale.com/files/sensors/doc/data_sheet/MPL3115A2.pdf) 76 * is a high-precision, ultra-low power consumption pressure sensor. Its operating 77 * range is 50-110 kPa. 78 * 79 * @image html mpl3115a2.jpg 80 * @snippet mpl3115a2.cxx Interesting 81 */ 82 class MPL3115A2 { 83 public: 84 /** 85 * Instantiates an MPL3115A2 object 86 * 87 * @param bus Number of the used bus 88 * @param devAddr Address of the used I2C device 89 * @param mode MPL3115A2 oversampling (6 = 64x) 90 */ 91 MPL3115A2(int bus, int devAddr=MPL3115A2_I2C_ADDRESS, uint8_t mode=6); 92 93 /** 94 * MPL3115A2 object destructor; basically, it closes the I2C connection. 95 * ~MPL3115A2(); 96 * no need for this here, as the I2c connection will be closed when the 97 * m_i2ControlCtx variable will go out of scope 98 **/ 99 100 /** 101 * Tests the sensor and tries to determine if the sensor is operating by looking 102 * for small variations in the value 103 */ 104 int testSensor(void); 105 106 /** 107 * Performs a soft reset of the MPL3115A2 device to ensure 108 * it is in a known state. This function can be used to reset 109 * the min/max temperature and pressure values. 110 */ 111 int resetSensor(void); 112 113 /** 114 * Dumps out the I2C register block to stdout 115 */ 116 void dumpSensor(void); 117 118 /** 119 * Initiates a temperature/pressure mesasurement and waits for the function 120 * to complete. Temperature and pressure registers can be read 121 * after this call. 122 */ 123 int sampleData(void); 124 125 /** 126 * Reads the pressure value from MPL3115A2 [Pa * 100] 127 * 128 * @param reg Base address of the pressure register 129 */ 130 int32_t getPressureReg(int reg); 131 132 /** 133 * Reads the temperature value from MPL3115A2 [degC * 1000] 134 * 135 * @param reg Base address of the temperature register 136 */ 137 int32_t getTempReg(int reg); 138 139 /** 140 * Reads the current pressure value from MPL3115A2 [Pa] 141 * 142 * @param bSampleData Sets non-zero to a sample reading 143 */ 144 float getPressure(int bSampleData = true); 145 146 /** 147 * Reads the current temperature value from MPL3115A2 [degC] 148 * 149 * @param bSampleData Sets non-zero to a sample reading 150 */ 151 float getTemperature(int bSampleData = true); 152 153 /** 154 * Reads the current pressure and, using a known altitude, calculates 155 * the sea level pressure value [Pa] 156 * This function should be preceded by the sampleData() call 157 * 158 * @param altitudeMeters Altitude in meters 159 */ 160 float getSealevelPressure(float altitudeMeters = 0.0); 161 162 /** 163 * Reads the current pressure and, using a known sea level pressure, 164 * calculates the altitude value [m] 165 * This function should be preceded by the sampleData() call 166 * 167 * @param sealevelPressure Current sea level pressure 168 */ 169 float getAltitude (float sealevelPressure = 101325.0); 170 171 /** 172 * Defines the oversampling setting (ranges from 0 to 7). The 173 * value represents 2^n samples (ranging from 1 to 128). The 174 * time to calculate a sample is approximately (2^n * 4 + 2) ms 175 * 176 * @param oversampling New oversampling value 177 */ 178 void setOversampling(uint8_t oversampling); 179 180 /** 181 * Returns the current oversampling value 182 */ 183 uint8_t getOversampling(void); 184 185 /** 186 * Reads the maximum measured temperature [degC] 187 */ 188 float getTemperatureMax(void); 189 190 /** 191 * Reads the minimum measured temperature [degC] 192 */ 193 float getTemperatureMin(void); 194 195 /** 196 * Reads the maximum measured pressure [Pa] 197 */ 198 float getPressureMax (void); 199 200 /** 201 * Reads the minimum measured pressure [Pa] 202 */ 203 float getPressureMin (void); 204 205 /** 206 * Converts temperature from degC*1000 to degF*1000 207 * 208 * @param iTemp Temperature in degC 209 */ 210 float convertTempCtoF(float fTemp); 211 212 /** 213 * Converts pressure from Pa*100 to inHg*10000 214 * This is set for 15degC (Pa = 0.0002961 in Hg) 215 * TODO: Change the function to add temperature calibration 216 * 217 * @param iPressure Pressure in Pa 218 */ 219 float convertPaToinHg(float fPressure); 220 221 /** 222 * Writes one byte to an I2C register 223 * 224 * @param reg Address of the register 225 * @param value Byte to be written 226 */ 227 mraa::Result i2cWriteReg (uint8_t reg, uint8_t value); 228 229 /** 230 * Reads two bytes from an I2C register 231 * 232 * @param reg Address of the register 233 */ 234 uint16_t i2cReadReg_16 (int reg); 235 236 /** 237 * Reads a one-byte register 238 * 239 * @param reg Address of the register 240 */ 241 uint8_t i2cReadReg_8 (int reg); 242 243 private: 244 std::string m_name; 245 246 int m_controlAddr; 247 int m_bus; 248 mraa::I2c m_i2ControlCtx; 249 250 uint8_t m_oversampling; 251 int32_t m_iPressure; 252 int32_t m_iTemperature; 253 }; 254 255 } 256 257
