Spiridion Mbed / BMP180

BMP180 Pressure/Temperature Sensor library

Dependents:   frdm_mikroklimat Weather_Station WMG Sample_BMP180 ... more

Yet another BMP180 library!

Bosch BMP180 is a pressure and temperature sensor which can be addressed through an I2C interface.

This library is based on the Bosch documentation (/media/uploads/spiridion/bst-bmp180-ds000-09.pdf ) and has been tested on LPC1768 and FRM-KL25Z plateforms using the BMP180 Sparkfun breakout (https://www.sparkfun.com/products/11824).

BMP180.h@1:072073c79cfd, 2014-03-17 (annotated)

Committer:
spiridion
Date:
Mon Mar 17 20:42:23 2014 +0000
Revision:
1:072073c79cfd
Parent:
0:9a0671b6009f 
remove calibration reading in constructor; and minor doc update

Who changed what in which revision?

UserRevisionLine numberNew contents of line
spiridion 0:9a0671b6009f 1 /*
spiridion 0:9a0671b6009f 2 @file BMP180.h
spiridion 0:9a0671b6009f 3
spiridion 0:9a0671b6009f 4 @brief Barometric Pressure and Temperature Sensor BMP180 Breakout I2C Library
spiridion 0:9a0671b6009f 5
spiridion 0:9a0671b6009f 6 @Author spiridion (http://mailme.spiridion.net)
spiridion 0:9a0671b6009f 7
spiridion 0:9a0671b6009f 8 Tested on LPC1768 and FRDM-KL25Z
spiridion 0:9a0671b6009f 9
spiridion 0:9a0671b6009f 10 Copyright (c) 2014 spiridion
spiridion 0:9a0671b6009f 11 Released under the MIT License (see http://mbed.org/license/mit)
spiridion 0:9a0671b6009f 12
spiridion 0:9a0671b6009f 13 Documentation regarding the BMP180 can be found here:
spiridion 1:072073c79cfd 14 http://mbed.org/media/uploads/spiridion/bst-bmp180-ds000-09.pdf
spiridion 0:9a0671b6009f 15 */
spiridion 0:9a0671b6009f 16
spiridion 0:9a0671b6009f 17 #ifndef BMP180_H
spiridion 0:9a0671b6009f 18 #define BMP180_H
spiridion 0:9a0671b6009f 19
spiridion 0:9a0671b6009f 20 #include "mbed.h"
spiridion 0:9a0671b6009f 21
spiridion 0:9a0671b6009f 22 /// default address is 0xEF
spiridion 0:9a0671b6009f 23 #define BMP180_I2C_ADDRESS 0xEF
spiridion 0:9a0671b6009f 24
spiridion 0:9a0671b6009f 25 // Oversampling settings
spiridion 0:9a0671b6009f 26 #define BMP180_OSS_ULTRA_LOW_POWER 0 // 1 sample and 4.5ms for conversion
spiridion 0:9a0671b6009f 27 #define BMP180_OSS_NORMAL 1 // 2 samples and 7.5ms for conversion
spiridion 0:9a0671b6009f 28 #define BMP180_OSS_HIGH_RESOLUTION 2 // 4 samples and 13.5ms for conversion
spiridion 0:9a0671b6009f 29 #define BMP180_OSS_ULTRA_HIGH_RESOLUTION 3 // 8 samples and 25.5ms for conversion
spiridion 0:9a0671b6009f 30
spiridion 0:9a0671b6009f 31 #define UNSET_BMP180_PRESSURE_VALUE 0.F
spiridion 0:9a0671b6009f 32 #define UNSET_BMP180_TEMPERATURE_VALUE -273.15F // absolute zero
spiridion 0:9a0671b6009f 33
spiridion 0:9a0671b6009f 34 /** BMP180 class.
spiridion 0:9a0671b6009f 35 * Read Pressure and temperature from the BMP180 Breakout I2C sensor
spiridion 0:9a0671b6009f 36 *
spiridion 0:9a0671b6009f 37 * Example:
spiridion 0:9a0671b6009f 38 * @code
spiridion 0:9a0671b6009f 39 * #include "mbed.h"
spiridion 0:9a0671b6009f 40 * #include "BMP180.h"
spiridion 0:9a0671b6009f 41 *
spiridion 0:9a0671b6009f 42 * #if defined(TARGET_LPC1768)
spiridion 0:9a0671b6009f 43 * #define PIN_SDA p9
spiridion 0:9a0671b6009f 44 * #define PIN_SCL p10
spiridion 0:9a0671b6009f 45 * #elif defined(TARGET_KL25Z) // watch out for the PTE0/PTE1 mixed up in the KL25Z doc
spiridion 0:9a0671b6009f 46 * #define PIN_SDA PTE0
spiridion 0:9a0671b6009f 47 * #define PIN_SCL PTE1
spiridion 0:9a0671b6009f 48 * #endif
spiridion 0:9a0671b6009f 49 *
spiridion 0:9a0671b6009f 50 * int main()
spiridion 0:9a0671b6009f 51 * {
spiridion 0:9a0671b6009f 52 * BMP180 bmp180(PIN_SDA, PIN_SCL);
spiridion 0:9a0671b6009f 53 * float pressure, temperature;
spiridion 0:9a0671b6009f 54 *
spiridion 1:072073c79cfd 55 * // bmp180.Initialize(); // no altitude compensation and normal oversampling
spiridion 1:072073c79cfd 56 * bmp180.Initialize(64, BMP180_OSS_ULTRA_LOW_POWER); // 64m altitude compensation and low power oversampling
spiridion 0:9a0671b6009f 57 *
spiridion 1:072073c79cfd 58 * while(1)
spiridion 1:072073c79cfd 59 * {
spiridion 0:9a0671b6009f 60 * if (bmp180.ReadData(&pressure, &temperature))
spiridion 0:9a0671b6009f 61 * printf("Pressure(hPa): %8.2f \t Temperature(C): %8.2f\n", pressure, temperature);
spiridion 0:9a0671b6009f 62 * wait(1);
spiridion 0:9a0671b6009f 63 * }
spiridion 0:9a0671b6009f 64 * }
spiridion 0:9a0671b6009f 65 * @endcode
spiridion 0:9a0671b6009f 66 */
spiridion 0:9a0671b6009f 67 class BMP180
spiridion 0:9a0671b6009f 68 {
spiridion 0:9a0671b6009f 69
spiridion 0:9a0671b6009f 70 public:
spiridion 0:9a0671b6009f 71
spiridion 0:9a0671b6009f 72 /** Create a BMP180 instance
spiridion 0:9a0671b6009f 73 * @param sda pin
spiridion 0:9a0671b6009f 74 * @param scl pin
spiridion 0:9a0671b6009f 75 * @param address: I2C slave address
spiridion 0:9a0671b6009f 76 */
spiridion 0:9a0671b6009f 77 BMP180(PinName sda, PinName scl, int address = BMP180_I2C_ADDRESS);
spiridion 0:9a0671b6009f 78
spiridion 0:9a0671b6009f 79 /** Create a BMP180 instance
spiridion 0:9a0671b6009f 80 * @param i2c object
spiridion 0:9a0671b6009f 81 * @param address: I2C slave address
spiridion 0:9a0671b6009f 82 */
spiridion 0:9a0671b6009f 83 BMP180(I2C& i2c, int address = BMP180_I2C_ADDRESS);
spiridion 0:9a0671b6009f 84
spiridion 0:9a0671b6009f 85 /** Initialization: set member values and read BMP180 calibration parameters
spiridion 0:9a0671b6009f 86 * @param altitude (in meter)
spiridion 0:9a0671b6009f 87 * @param overSamplingSetting
spiridion 0:9a0671b6009f 88 */
spiridion 0:9a0671b6009f 89 int Initialize(float altitude = 0.F, int overSamplingSetting = BMP180_OSS_NORMAL);
spiridion 0:9a0671b6009f 90
spiridion 0:9a0671b6009f 91 /** Read pressure and temperature from the BMP180.
spiridion 0:9a0671b6009f 92 * @param pressure (hPa)
spiridion 0:9a0671b6009f 93 * @param temperature (C)
spiridion 0:9a0671b6009f 94 * @returns
spiridion 0:9a0671b6009f 95 * 1 on success,
spiridion 0:9a0671b6009f 96 * 0 on error
spiridion 0:9a0671b6009f 97 */
spiridion 0:9a0671b6009f 98 int ReadData(float* pTemperature = NULL, float* pPressure = NULL);
spiridion 0:9a0671b6009f 99
spiridion 0:9a0671b6009f 100 /** Get temperature from a previous measurement
spiridion 0:9a0671b6009f 101 *
spiridion 0:9a0671b6009f 102 * @returns
spiridion 0:9a0671b6009f 103 * temperature (C)
spiridion 0:9a0671b6009f 104 */
spiridion 0:9a0671b6009f 105 float GetTemperature() {return m_temperature;};
spiridion 0:9a0671b6009f 106
spiridion 0:9a0671b6009f 107 /** Get pressure from a previous measurement
spiridion 0:9a0671b6009f 108 *
spiridion 0:9a0671b6009f 109 * @returns
spiridion 0:9a0671b6009f 110 * pressure (hPa)
spiridion 0:9a0671b6009f 111 */
spiridion 0:9a0671b6009f 112 float GetPressure() {return m_pressure;};
spiridion 0:9a0671b6009f 113
spiridion 0:9a0671b6009f 114 protected:
spiridion 0:9a0671b6009f 115
spiridion 0:9a0671b6009f 116 /** Perform temperature measurement
spiridion 0:9a0671b6009f 117 *
spiridion 0:9a0671b6009f 118 * @returns
spiridion 0:9a0671b6009f 119 * temperature (C)
spiridion 0:9a0671b6009f 120 */
spiridion 0:9a0671b6009f 121 int ReadRawTemperature(long* pUt);
spiridion 0:9a0671b6009f 122
spiridion 0:9a0671b6009f 123 /** Perform pressure measurement
spiridion 0:9a0671b6009f 124 *
spiridion 0:9a0671b6009f 125 * @returns
spiridion 0:9a0671b6009f 126 * temperature (C)
spiridion 0:9a0671b6009f 127 */
spiridion 0:9a0671b6009f 128 int ReadRawPressure(long* pUp);
spiridion 0:9a0671b6009f 129
spiridion 0:9a0671b6009f 130 /** Calculation of the temperature from the digital output
spiridion 0:9a0671b6009f 131 */
spiridion 0:9a0671b6009f 132 float TrueTemperature(long ut);
spiridion 0:9a0671b6009f 133
spiridion 0:9a0671b6009f 134 /** Calculation of the pressure from the digital output
spiridion 0:9a0671b6009f 135 */
spiridion 0:9a0671b6009f 136 float TruePressure(long up);
spiridion 0:9a0671b6009f 137
spiridion 0:9a0671b6009f 138 int m_oss;
spiridion 0:9a0671b6009f 139 float m_temperature;
spiridion 0:9a0671b6009f 140 float m_pressure;
spiridion 0:9a0671b6009f 141 float m_altitude;
spiridion 0:9a0671b6009f 142
spiridion 0:9a0671b6009f 143 I2C m_i2c;
spiridion 0:9a0671b6009f 144 int m_addr;
spiridion 0:9a0671b6009f 145 char m_data[4];
spiridion 0:9a0671b6009f 146
spiridion 0:9a0671b6009f 147 short ac1, ac2, ac3;
spiridion 0:9a0671b6009f 148 unsigned short ac4, ac5, ac6;
spiridion 0:9a0671b6009f 149 short b1, b2;
spiridion 0:9a0671b6009f 150 short mb, mc, md;
spiridion 0:9a0671b6009f 151 long x1, x2, x3, b3, b5, b6;
spiridion 0:9a0671b6009f 152 unsigned long b4, b7;
spiridion 0:9a0671b6009f 153
spiridion 0:9a0671b6009f 154 };
spiridion 0:9a0671b6009f 155
spiridion 0:9a0671b6009f 156 #endif