Device driver for the BMP180 Digital pressure and temperature sensor.
Dependents: BMP180_example MAXWSNENV_sensors MAXWSNENV_sensors nRF51822_BMP180 ... more
BMP180 Device Driver
This is a device driver for the BMP180 Digital pressure sensor. It uses I2C to communicate pressure and temperature data.
Diff: BMP180.h
- Revision:
- 0:b2219e6e444b
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/BMP180.h Fri Apr 17 09:31:09 2015 -0500 @@ -0,0 +1,230 @@ +/******************************************************************************* + * 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. + ******************************************************************************* + */ + +#ifndef _BMP180_H_ +#define _BMP180_H_ + +#include "mbed.h" + +/** + * Bosch BMP180 Digital Pressure Sensor + * + * @code + * #include <stdio.h> + * #include "mbed.h" + * #include "BMP180.h" + * + * 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 +{ + +public: + + /** + * @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. + */ + 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; + + /** + * 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(PinName sda, PinName scl); + + /** + * BMP180 constructor. + * + * @param i2c I2C object to use. + */ + BMP180(I2C *i2c); + + /** + * BMP180 destructor. + */ + ~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); + + /** + * @brief Check ID. + * @details Checks the device ID, should be 0x55 on reset. + * @returns 0 if no errors, -1 if error. + */ + int checkId(void); + + /** + * @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); + + /** + * @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); + + /** + * @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); + + /** + * @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); + + /** + * @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); + +private: + + 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 *i2c_; + bool i2c_owner; + + BMP180::calibration_t calib; + int32_t b5; + BMP180::oversampling_t oss_; +}; + +#endif /* _BMP180_H_ */