Diff: BMP180.h

Revision:

2:5b3e84563dcb

Parent:

1:072073c79cfd

--- 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_ */