BMP180 Pressure/Temperature Sensor library
Dependents: LinkNode_TemperatureAdvertising
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Revision 2:5b3e84563dcb, committed 2016-03-02
- Comitter:
- helloqi
- Date:
- Wed Mar 02 05:45:36 2016 +0000
- Parent:
- 1:072073c79cfd
- Commit message:
- temperature advertising
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diff -r 072073c79cfd -r 5b3e84563dcb BMP180.cpp --- a/BMP180.cpp Mon Mar 17 20:42:23 2014 +0000 +++ b/BMP180.cpp Wed Mar 02 05:45:36 2016 +0000 @@ -1,226 +1,268 @@ -/* - @file BMP180.cpp - - @brief Barometric Pressure and Temperature Sensor BMP180 Breakout I2C Library - - @Author spiridion (http://mailme.spiridion.net) - - 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 -*/ +/******************************************************************************* + * 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. + ******************************************************************************* + */ #include "BMP180.h" -#include "mbed.h" + +/***** Definitions *****/ +#define I2C_ADDR (0xEE) // 1110111x -// Uncomment to test the documentation algorithm against the documentation example -// Result should be 699.64 hPa and 15°C -// #define BMP180_TEST_FORMULA +#define REG_ADDR_RESET (0xE0) +#define REG_ADDR_ID (0xD0) +#define REG_ADDR_CTRL (0xF4) +#define REG_ADDR_DATA (0xF6) +#define REG_ADDR_AC1 (0xAA) -BMP180::BMP180(PinName sda, PinName scl, int address) - : m_i2c(sda,scl), m_addr(address) +#define CTRL_REG_TEMP (0x2E) +#define CTRL_REG_PRESS_0 (0x34) +#define CTRL_REG_PRESS_1 (0x74) +#define CTRL_REG_PRESS_2 (0xB4) +#define CTRL_REG_PRESS_3 (0xF4) + +//****************************************************************************** +BMP180::BMP180(PinName sda, PinName scl) { - m_altitude = 0; - m_oss = BMP180_OSS_NORMAL; - m_temperature = UNSET_BMP180_TEMPERATURE_VALUE; - m_pressure = UNSET_BMP180_PRESSURE_VALUE; -} + i2c_ = new I2C(sda, scl); + i2c_owner = true; -BMP180::BMP180(I2C& i2c, int address) - : m_i2c(i2c), m_addr(address) -{ - m_altitude = 0; - m_oss = BMP180_OSS_NORMAL; - m_temperature = UNSET_BMP180_TEMPERATURE_VALUE; - m_pressure = UNSET_BMP180_PRESSURE_VALUE; + i2c_->frequency(400000); //400000 } -int BMP180::Initialize(float altitude, int overSamplingSetting) +//****************************************************************************** +BMP180::BMP180(I2C *i2c) : + i2c_(i2c) { - char data[22]; - int errors = 0; - - m_altitude = altitude; - m_oss = overSamplingSetting; - m_temperature = UNSET_BMP180_TEMPERATURE_VALUE; - m_pressure = UNSET_BMP180_PRESSURE_VALUE; - - // read calibration data - data[0]=0xAA; - errors = m_i2c.write(m_addr, data, 1); // set the eeprom pointer position to 0xAA - errors += m_i2c.read(m_addr, data, 22); // read 11 x 16 bits at this position - wait_ms(10); - - // store calibration data for further calculus - ac1 = data[0] << 8 | data[1]; - ac2 = data[2] << 8 | data[3]; - ac3 = data[4] << 8 | data[5]; - ac4 = data[6] << 8 | data[7]; - ac5 = data[8] << 8 | data[9]; - ac6 = data[10] << 8 | data[11]; - b1 = data[12] << 8 | data[13]; - b2 = data[14] << 8 | data[15]; - mb = data[16] << 8 | data[17]; - mc = data[18] << 8 | data[19]; - md = data[20] << 8 | data[21]; + i2c_owner = false; +} -#ifdef BMP180_TEST_FORMULA - ac1 = 408; - ac2 = -72; - ac3 = -14383; - ac4 = 32741; - ac5 = 32757; - ac6 = 23153; - b1 = 6190; - b2 = 4; - mb = -32768; - mc = -8711; - md = 2868; - m_oss = 0; - errors = 0; -#endif // #ifdef BMP180_TEST_FORMULA - - return errors? 0 : 1; +//****************************************************************************** +BMP180::~BMP180() +{ + if(i2c_owner) { + delete i2c_; + } } -int BMP180::ReadData(float* pTemperature, float* pPressure) +//****************************************************************************** +int BMP180::init(void) { - long t, p; + char addr; + char data[22]; + int i; - if (!ReadRawTemperature(&t) || !ReadRawPressure(&p)) - { - m_temperature = UNSET_BMP180_TEMPERATURE_VALUE; - m_pressure = UNSET_BMP180_PRESSURE_VALUE; - return 0; + if (checkId() != 0) { + return -1; + } + + addr = REG_ADDR_AC1; + if (i2c_->write(I2C_ADDR, &addr, 1) != 0) { + return -1; + } + + if (i2c_->read(I2C_ADDR, data, 22) != 0) { + return -1; } - m_temperature = TrueTemperature(t); - m_pressure = TruePressure(p); + for (i = 0; i < 11; i++) { + calib.value[i] = (data[2*i] << 8) | data[(2*i)+1]; + } + + return 0; +} + +//****************************************************************************** +int BMP180::reset(void) +{ + char data; - if (pPressure) - *pPressure = m_pressure; - if (pTemperature) - *pTemperature = m_temperature; + data = REG_ADDR_RESET; + if (i2c_->write(I2C_ADDR, &data, 1) != 0) { + return -1; + } - return 1; + data = 0xB6; + if (i2c_->write(I2C_ADDR, &data, 1) != 0) { + return -1; + } + + return 0; } -int BMP180::ReadRawTemperature(long* pUt) +//****************************************************************************** +int BMP180::checkId(void) { - int errors = 0; - char data[2]; - - // request temperature measurement - data[0] = 0xF4; - data[1] = 0x2E; - errors = m_i2c.write(m_addr, data, 2); // write 0XF2 into reg 0XF4 - - wait_ms(4.5F); + char addr; + char data; - // read raw temperature data - data[0] = 0xF6; - errors += m_i2c.write(m_addr, data, 2); // set eeprom pointer position to 0XF6 - errors += m_i2c.read(m_addr, data, 2); // get 16 bits at this position - -#ifdef BMP180_TEST_FORMULA - errors = 0; -#endif // #ifdef BMP180_TEST_FORMULA + addr = REG_ADDR_ID; + if (i2c_->write(I2C_ADDR, &addr, 1) != 0) { + return -1; + } - if (errors) - return 0; - else - *pUt = data[0] << 8 | data[1]; + if (i2c_->read(I2C_ADDR, &data, 1) != 0) { + return -1; + } -#ifdef BMP180_TEST_FORMULA - *pUt = 27898; -#endif // #ifdef BMP180_TEST_FORMULA - - return 1; + if (data != 0x55) { + return -1; + } + + return 0; } -int BMP180::ReadRawPressure(long* pUp) +//****************************************************************************** +int BMP180::startPressure(BMP180::oversampling_t oss) { - int errors = 0; char data[2]; - - // request pressure measurement - data[0] = 0xF4; - data[1] = 0x34 + (m_oss << 6); - errors = m_i2c.write(m_addr, data, 2); // write 0x34 + (m_oss << 6) into reg 0XF4 + + data[0] = REG_ADDR_CTRL; + data[1] = CTRL_REG_PRESS_0 | ((oss & 0x3) << 6); + oss_ = oss; + + if (i2c_->write(I2C_ADDR, data, 2) != 0) { + return -1; + } + + return 0; +} - switch (m_oss) - { - case BMP180_OSS_ULTRA_LOW_POWER: wait_ms(4.5); break; - case BMP180_OSS_NORMAL: wait_ms(7.5); break; - case BMP180_OSS_HIGH_RESOLUTION: wait_ms(13.5); break; - case BMP180_OSS_ULTRA_HIGH_RESOLUTION: wait_ms(25.5); break; +//****************************************************************************** +int BMP180::getPressure(int *pressure) +{ + char addr, byte[3]; + uint32_t up; + int32_t b6, x1, x2, x3, b3, p; + uint32_t b4, b7; + + addr = REG_ADDR_DATA; + if (i2c_->write(I2C_ADDR, &addr, 1) != 0) { + return -1; + } + + if (i2c_->read(I2C_ADDR, byte, 3) != 0) { + return -1; } - // read raw pressure data - data[0] = 0xF6; - errors += m_i2c.write(m_addr, data, 1); // set eeprom pointer position to 0XF6 - errors += m_i2c.read(m_addr, data, 2); // get 16 bits at this position - -#ifdef BMP180_TEST_FORMULA - errors = 0; -#endif // #ifdef BMP180_TEST_FORMULA + up = ((byte[0] << 16) | (byte[1] << 8) | byte[2]) >> (8 - oss_); + + b6 = b5 - 4000; + x1 = (b6 * b6) >> 12; + x1 *= calib.b2; + x1 >>= 11; + x2 = calib.ac2 * b6; + x2 >>= 11; + x3 = x1 + x2; + b3 = (((((int32_t)calib.ac1) * 4 + x3) << oss_) + 2); + b3 >>= 2; - if (errors) - return 0; - else - *pUp = (data[0] << 16 | data[1] << 8) >> (8 - m_oss); -#ifdef BMP180_TEST_FORMULA - *pUp = 23843; -#endif // #ifdef BMP180_TEST_FORMULA + x1 = (calib.ac3 * b6) >> 13; + x2 = (calib.b1 * ((b6 * b6) >> 12)) >> 16; + x3 = (x1 + x2 + 2) >> 2; + b4 = (calib.ac4 * (uint32_t)(x3 + 32768)) >> 15; + b7 = ((uint32_t)up - b3) * (50000 >> oss_); + p = ((b7 < 0x80000000) ? ((b7 << 1) / b4) : ((b7 / b4) * 2)); + x1 = p >> 8; + x1 *= x1; + x1 = (x1 * 3038) >> 16; + x2 = (-7357 * p) >> 16; + p += (x1 + x2 + 3791) >> 4; + + *pressure = p; - return 1; + return 0; +} + +//****************************************************************************** +int BMP180::startTemperature(void) +{ + char data[2] = { REG_ADDR_CTRL, CTRL_REG_TEMP }; + + if (i2c_->write(I2C_ADDR, data, 2) != 0) { + return -1; + } + + return 0; } -float BMP180::TrueTemperature(long ut) +//****************************************************************************** +int BMP180::getTemperature(float *tempC) { - long t; - - // straight out from the documentation - x1 = ((ut - ac6) * ac5) >> 15; - x2 = ((long)mc << 11) / (x1 + md); + char addr, byte[2]; + uint16_t ut; + int32_t x1, x2; + + addr = REG_ADDR_DATA; + if (i2c_->write(I2C_ADDR, &addr, 1) != 0) { + return -1; + } + + if (i2c_->read(I2C_ADDR, byte, 2) != 0) { + return -1; + } + + ut = (byte[0] << 8) | byte[1]; + + x1 = ((ut - calib.ac6) * calib.ac5) >> 15; + x2 = (calib.mc << 11) / (x1 + calib.md); b5 = x1 + x2; - t = (b5 + 8) >> 4; - // convert to celcius - return t / 10.F; + *tempC = (float)(b5 + 8) / 160; + + return 0; } -float BMP180::TruePressure(long up) +//****************************************************************************** +int BMP180::getTemperature(int16_t *tempCx10) { - long p; - - // straight out from the documentation - b6 = b5 - 4000; - x1 = (b2 * (b6 * b6 >> 12)) >> 11; - x2 = ac2 * b6 >> 11; - x3 = x1 + x2; - b3 = (((ac1 * 4 + x3) << m_oss) + 2) >> 2; - x1 = (ac3 * b6) >> 13; - x2 = (b1 * ((b6 * b6) >> 12)) >> 16; - x3 = ((x1 + x2) + 2) >> 2; - b4 = ac4 * (unsigned long)(x3 + 32768) >> 15; - b7 = ((unsigned long)up - b3)* (50000 >> m_oss); - if (b7 < 0x80000000) - p = (b7 << 1) / b4; - else - p = (b7 / b4) << 1; - x1 = (p >> 8) * (p >> 8); - x1 = (x1 * 3038) >> 16; - x2 = (-7357 * p) >> 16; - p = p + ((x1 + x2 + 3791) >> 4); + char addr, byte[2]; + uint16_t ut; + int32_t x1, x2; + + addr = REG_ADDR_DATA; + if (i2c_->write(I2C_ADDR, &addr, 1) != 0) { + return -1; + } - // convert to hPa and, if altitude has been initialized, to sea level pressure - if (m_altitude == 0.F) - return p / 100.F; - else - return p / (100.F * pow((1.F - m_altitude / 44330.0L), 5.255L)); -} \ No newline at end of file + if (i2c_->read(I2C_ADDR, byte, 2) != 0) { + return -1; + } + + ut = (byte[0] << 8) | byte[1]; + + x1 = ((ut - calib.ac6) * calib.ac5) >> 15; + x2 = (calib.mc << 11) / (x1 + calib.md); + b5 = x1 + x2; + + *tempCx10 = (b5 + 8) >> 4; + + return 0; +}
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_ */