BMP180 Pressure/Temperature Sensor library
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Diff: BMP180.h
- Revision:
- 2:5b3e84563dcb
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- 1:072073c79cfd
diff -r 072073c79cfd -r 5b3e84563dcb BMP180.h --- a/BMP180.h Mon Mar 17 20:42:23 2014 +0000 +++ b/BMP180.h Wed Mar 02 05:45:36 2016 +0000 @@ -1,156 +1,230 @@ -/* - @file BMP180.h - - @brief Barometric Pressure and Temperature Sensor BMP180 Breakout I2C Library - - @Author spiridion (http://mailme.spiridion.net) +/******************************************************************************* + * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES + * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + * + * Except as contained in this notice, the name of Maxim Integrated + * Products, Inc. shall not be used except as stated in the Maxim Integrated + * Products, Inc. Branding Policy. + * + * The mere transfer of this software does not imply any licenses + * of trade secrets, proprietary technology, copyrights, patents, + * trademarks, maskwork rights, or any other form of intellectual + * property whatsoever. Maxim Integrated Products, Inc. retains all + * ownership rights. + ******************************************************************************* + */ - Tested on LPC1768 and FRDM-KL25Z - - Copyright (c) 2014 spiridion - Released under the MIT License (see http://mbed.org/license/mit) - - Documentation regarding the BMP180 can be found here: - http://mbed.org/media/uploads/spiridion/bst-bmp180-ds000-09.pdf -*/ - -#ifndef BMP180_H -#define BMP180_H +#ifndef _BMP180_H_ +#define _BMP180_H_ #include "mbed.h" -/// default address is 0xEF -#define BMP180_I2C_ADDRESS 0xEF - -// Oversampling settings -#define BMP180_OSS_ULTRA_LOW_POWER 0 // 1 sample and 4.5ms for conversion -#define BMP180_OSS_NORMAL 1 // 2 samples and 7.5ms for conversion -#define BMP180_OSS_HIGH_RESOLUTION 2 // 4 samples and 13.5ms for conversion -#define BMP180_OSS_ULTRA_HIGH_RESOLUTION 3 // 8 samples and 25.5ms for conversion - -#define UNSET_BMP180_PRESSURE_VALUE 0.F -#define UNSET_BMP180_TEMPERATURE_VALUE -273.15F // absolute zero - -/** BMP180 class. - * Read Pressure and temperature from the BMP180 Breakout I2C sensor +/** + * Bosch BMP180 Digital Pressure Sensor * - * Example: * @code + * #include <stdio.h> * #include "mbed.h" * #include "BMP180.h" - * - * #if defined(TARGET_LPC1768) - * #define PIN_SDA p9 - * #define PIN_SCL p10 - * #elif defined(TARGET_KL25Z) // watch out for the PTE0/PTE1 mixed up in the KL25Z doc - * #define PIN_SDA PTE0 - * #define PIN_SCL PTE1 - * #endif - * - * int main() - * { - * BMP180 bmp180(PIN_SDA, PIN_SCL); - * float pressure, temperature; - * - * // bmp180.Initialize(); // no altitude compensation and normal oversampling - * bmp180.Initialize(64, BMP180_OSS_ULTRA_LOW_POWER); // 64m altitude compensation and low power oversampling - * - * while(1) - * { - * if (bmp180.ReadData(&pressure, &temperature)) - * printf("Pressure(hPa): %8.2f \t Temperature(C): %8.2f\n", pressure, temperature); + * + * I2C i2c(I2C_SDA, I2C_SCL); + * BMP180 bmp180(&i2c); + * + * int main(void) { + * + * while(1) { + * if (bmp180.init() != 0) { + * printf("Error communicating with BMP180\n"); + * } else { + * printf("Initialized BMP180\n"); + * break; + * } + * wait(1); + * } + * + * while(1) { + * bmp180.startTemperature(); + * wait_ms(5); // Wait for conversion to complete + * float temp; + * if(bmp180.getTemperature(&temp) != 0) { + * printf("Error getting temperature\n"); + * continue; + * } + * + * bmp180.startPressure(BMP180::ULTRA_LOW_POWER); + * wait_ms(10); // Wait for conversion to complete + * int pressure; + * if(bmp180.getPressure(&pressure) != 0) { + * printf("Error getting pressure\n"); + * continue; + * } + * + * printf("Pressure = %d Pa Temperature = %f C\n", pressure, temp); * wait(1); * } * } * @endcode */ -class BMP180 +class BMP180 { public: - /** Create a BMP180 instance - * @param sda pin - * @param scl pin - * @param address: I2C slave address + /** + * @brief Oversampling ratio. + * @details Dictates how many pressure samples to take. Conversion time varies + * depending on the number of samples taken. Refer to data sheet + * for timing specifications. */ - BMP180(PinName sda, PinName scl, int address = BMP180_I2C_ADDRESS); + typedef enum { + ULTRA_LOW_POWER = 0, ///< 1 pressure sample + STANDARD = 1, ///< 2 pressure samples + HIGH_RESOLUTION = 2, ///< 4 pressure samples + ULTRA_HIGH_RESOLUTION = 3, ///< 8 pressure samples + } oversampling_t; - /** Create a BMP180 instance - * @param i2c object - * @param address: I2C slave address + /** + * BMP180 constructor. + * + * @param sda mbed pin to use for SDA line of I2C interface. + * @param scl mbed pin to use for SCL line of I2C interface. */ - BMP180(I2C& i2c, int address = BMP180_I2C_ADDRESS); + BMP180(PinName sda, PinName scl); - /** Initialization: set member values and read BMP180 calibration parameters - * @param altitude (in meter) - * @param overSamplingSetting + /** + * BMP180 constructor. + * + * @param i2c I2C object to use. + */ + BMP180(I2C *i2c); + + /** + * BMP180 destructor. */ - int Initialize(float altitude = 0.F, int overSamplingSetting = BMP180_OSS_NORMAL); + ~BMP180(); + + /** + * @brief Initialize BMP180. + * @details Gets the device ID and saves the calibration values. + * @returns 0 if no errors, -1 if error. + */ + int init(void); + + /** + * @brief Reset BMP180. + * @details Performs a soft reset of the device. Same sequence as power on reset. + * @returns 0 if no errors, -1 if error. + */ + int reset(void); - /** Read pressure and temperature from the BMP180. - * @param pressure (hPa) - * @param temperature (C) - * @returns - * 1 on success, - * 0 on error - */ - int ReadData(float* pTemperature = NULL, float* pPressure = NULL); + /** + * @brief Check ID. + * @details Checks the device ID, should be 0x55 on reset. + * @returns 0 if no errors, -1 if error. + */ + int checkId(void); - /** Get temperature from a previous measurement - * - * @returns - * temperature (C) - */ - float GetTemperature() {return m_temperature;}; + /** + * @brief Start pressure conversion. + * @details Initiates the pressure conversion sequence. Refer to data sheet + * for timing specifications. + * + * @param oss Number of samples to take. + * @returns 0 if no errors, -1 if error. + */ + int startPressure(BMP180::oversampling_t oss); - /** Get pressure from a previous measurement - * - * @returns - * pressure (hPa) - */ - float GetPressure() {return m_pressure;}; - -protected: + /** + * @brief Get pressure reading. + * @details Calculates the pressure using the data calibration data and formula. + * Pressure is reported in Pascals. + * @note This function should be called after calling startPressure(). + * Refer to the data sheet for the timing requirements. Calling this + * function too soon can result in oversampling. + * + * @param pressure Pointer to store pressure reading. + * @returns 0 if no errors, -1 if error. + */ + int getPressure(int *pressure); - /** Perform temperature measurement - * - * @returns - * temperature (C) - */ - int ReadRawTemperature(long* pUt); + /** + * @brief Start temperature conversion. + * @details Initiates the temperature conversion sequence. Refer to data + * sheet for timing specifications. + * @returns 0 if no errors, -1 if error. + */ + int startTemperature(void); - /** Perform pressure measurement - * - * @returns - * temperature (C) - */ - int ReadRawPressure(long* pUp); + /** + * @brief Get temperature reading. + * @details Calculates the temperature using the data calibration data and formula. + * Temperature is reported in degrees Celcius. + * + * @note This function should be called after calling startTemperature(). + * Refer to the data sheet for the timing requirements. Calling this + * function too soon can result in oversampling. + * + * @param tempC Pointer to store temperature reading. + * @returns 0 if no errors, -1 if error. + */ + int getTemperature(float *tempC); - /** Calculation of the temperature from the digital output - */ - float TrueTemperature(long ut); + /** + * @brief Get temperature reading. + * @details Calculates the temperature using the data calibration data and formula. + * Temperature is reported in 1/10ths degrees Celcius. + * + * @note This function should be called after calling startTemperature(). + * Refer to the data sheet for the timing requirements. Calling this + * function too soon can result in oversampling. + * + * @param tempCx10 Pointer to store temperature reading. + * @returns 0 if no errors, -1 if error. + */ + int getTemperature(int16_t *tempCx10); - /** Calculation of the pressure from the digital output - */ - float TruePressure(long up); +private: - int m_oss; - float m_temperature; - float m_pressure; - float m_altitude; + typedef union { + uint16_t value[11]; + struct { + int16_t ac1; + int16_t ac2; + int16_t ac3; + uint16_t ac4; + uint16_t ac5; + uint16_t ac6; + int16_t b1; + int16_t b2; + int16_t mb; + int16_t mc; + int16_t md; + }; + } calibration_t; - I2C m_i2c; - int m_addr; - char m_data[4]; + I2C *i2c_; + bool i2c_owner; - short ac1, ac2, ac3; - unsigned short ac4, ac5, ac6; - short b1, b2; - short mb, mc, md; - long x1, x2, x3, b3, b5, b6; - unsigned long b4, b7; - + BMP180::calibration_t calib; + int32_t b5; + BMP180::oversampling_t oss_; }; -#endif \ No newline at end of file +#endif /* _BMP180_H_ */