Revision 2:8c00953d4755, committed 2012-11-06

Comitter:

tylerjw

Date:

Tue Nov 06 02:39:40 2012 +0000

Parent:

1:2935199329b2

Child:

3:ae2b8103e52b

Commit message:

library initial commit;

Changed in this revision

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/BMP085.cpp	Tue Nov 06 02:39:40 2012 +0000
@@ -0,0 +1,234 @@
+/*
+ * @file BMP085.cpp
+ * @author Tyler Weaver
+ * @author Kory Hill
+ *
+ * @section LICENSE
+ *
+ * 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 THE AUTHORS OR COPYRIGHT HOLDERS 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.
+ *
+ * @section DESCRIPTION
+ *
+ * BMP085 I2C Temperature/Pressure/Altitude Sensor
+ *
+ * Datasheet:
+ *
+ * http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Pressure/BST-BMP085-DS000-06.pdf
+ */
+
+#include "BMP085.h"
+#include <new>
+
+BMP085::BMP085(PinName sda, PinName scl) : i2c_(*reinterpret_cast<I2C*>(i2cRaw))
+{
+    // Placement new to avoid additional heap memory allocation.
+    new(i2cRaw) I2C(sda, scl);
+
+    init();
+}
+
+BMP085::~BMP085()
+{
+    // If the I2C object is initialized in the buffer in this object, call destructor of it.
+    if(&i2c_ == reinterpret_cast<I2C*>(&i2cRaw))
+        reinterpret_cast<I2C*>(&i2cRaw)->~I2C();
+}
+
+void BMP085::init()
+{
+    get_cal_param();
+    set_oss(8); // standard over sampling (2 samples)
+    get_ut(); // initalize values
+    get_up();
+}
+
+void BMP085::get_cal_param()
+{
+    // get calibration values
+    AC1 = read_int16(0xAA);
+    AC2 = read_int16(0xAC);
+    AC3 = read_int16(0xAE);
+    AC4 = read_uint16(0xB0);
+    AC5 = read_uint16(0xB2);
+    AC6 = read_uint16(0xB4);
+    B1  = read_int16(0xB6);
+    B2  = read_int16(0xB8);
+    MB  = read_int16(0xBA);
+    MC  = read_int16(0xBC);
+    MD  = read_int16(0xBE);
+}
+
+void BMP085::display_cal_param(Serial *pc)
+{
+    pc->printf("AC1 %x\r\n", AC1);
+    pc->printf("AC2 %x\r\n", AC2);
+    pc->printf("AC3 %x\r\n", AC3);
+    pc->printf("AC4 %x\r\n", AC4);
+    pc->printf("AC5 %x\r\n", AC5);
+    pc->printf("AC6 %x\r\n", AC6);
+    pc->printf("B1 %x\r\n", B1);
+    pc->printf("B2 %x\r\n", B2);
+    pc->printf("MB %x\r\n", MB);
+    pc->printf("MC %x\r\n", MC);
+    pc->printf("MD %x\r\n", MD);
+}
+
+void BMP085::get_ut()
+{
+    write_char(0xF4,0x2E);
+    wait(0.045);
+    char buffer[3];
+    read_multiple(0xF6, buffer, 2);
+    
+    UT = (buffer[0]<<8) | buffer[1];
+}
+
+void BMP085::get_up()
+{
+    // set sample setting
+    write_char(0xF4, oversampling_setting_);
+    
+    // wait
+    wait(conversion_time_);
+    
+    // read the three bits
+    char buffer[3];
+    read_multiple(0xF6, buffer, 3);
+    
+    UP = ((buffer[0]<<16) | (buffer[1]<<8) | (buffer[2])) >> (8 - oss_bit_);
+}
+
+void BMP085::set_oss(int oss)
+{
+    switch(oss) {
+        case 1: // low power
+            oss_bit_ = 0;
+            oversampling_setting_ = 0x34;
+            conversion_time_ = 0.045;
+            break;
+        case 2: // standard
+            oss_bit_ = 1;
+            oversampling_setting_ = 0x74;
+            conversion_time_ = 0.075;
+            break;
+        case 4: // high resolution
+            oss_bit_ = 2;
+            oversampling_setting_ = 0xB4;
+            conversion_time_ = 0.135;
+            break;
+        case 8: // ultra high resolution
+            oss_bit_ = 3;
+            oversampling_setting_ = 0xF4;
+            conversion_time_ = 0.255;
+            break;
+        default: // standard
+            oss_bit_ = 1;
+            oversampling_setting_ = 0x74;
+            conversion_time_ = 0.075;
+    }
+}
+
+void BMP085::write_char(char address, char data)
+{
+    char cmd[2];
+    cmd[0] = address;
+    cmd[1] = data;
+    i2c_.write( I2C_ADDRESS , cmd, 2);
+}
+
+int16_t BMP085::read_int16(char address)
+{
+    char tx[2];
+    tx[0] = address;
+    i2c_.write(I2C_ADDRESS, tx, 1);
+    i2c_.read(I2C_ADDRESS, tx, 2);
+    int16_t value = ((tx[0] << 8) | tx[1]);
+    return value;
+}
+
+void BMP085::read_multiple(char address, char* buffer, int bits)
+{
+    char cmd[2];
+    cmd[0] = address;
+    i2c_.write(I2C_ADDRESS, cmd, 1);
+    i2c_.read(I2C_ADDRESS, buffer, bits);
+}
+
+uint16_t BMP085::read_uint16(char address)
+{
+    char tx[2];
+    tx[0] = address;
+    i2c_.write(I2C_ADDRESS, tx, 1);
+    i2c_.read(I2C_ADDRESS, tx, 2);
+    uint16_t value = ((tx[0] << 8) | tx[1]);
+    return value;
+}
+
+int32_t BMP085::get_temperature()
+{
+    get_ut(); // uncompressed temperature
+    get_up(); // uncompressed pressure
+    
+    long x1,x2;
+
+    //Start temperature calculation
+    x1 = ((UT - AC6) * AC5) >> 15;
+    x2 = (MC << 11) / (x1 + MD);
+    B5 = x1 + x2;
+    temperature = ((B5 + 8) >> 4);
+    return temperature;
+}
+
+int32_t BMP085::get_pressure()
+{
+    get_up(); // get uncompressed pressure (uncompressed temperature must be called recently)
+
+    B6 = B5 - 4000;
+    X1 = (B2 * ((B6 * B6) >> 12)) >> 11;
+    X2 = (AC2 * B6) >> 11;
+    X3 = X1 + X2;
+    B3 = ((((((long)(AC1) * 4) + X3) << oss_bit_) + 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 >> oss_bit_));
+    if (B7 < 0x80000000)
+        pressure = (B7 << 1) / B4;
+    else
+        pressure = (B7 / B4) << 1;
+
+    X1 = (pressure >> 8);
+    X1 *= X1;
+    X1 = (X1 * 3038) >>16;
+    X2 = (-7357 * pressure) >>16;
+    pressure += (X1 + X2 + 3791)>>4;
+    
+    return pressure;
+}
+
+double BMP085::get_altitude_m()
+{
+    const double P0 = 1013.25; //pressure at sea level in hPa
+    double pres_hpa = pressure / 100.0;
+    altitude = 44330.0 * (1.0 - pow((pres_hpa/P0), 0.190295));
+    return altitude;
+}
+
+double BMP085::get_altitude_ft()
+{
+    return get_altitude_m()*3.28084;
+}
\ No newline at end of file

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/BMP085.h	Tue Nov 06 02:39:40 2012 +0000
@@ -0,0 +1,129 @@
+/*
+ * @file BMP085.h
+ * @author Tyler Weaver
+ * @author Kory Hill
+ *
+ * @section LICENSE
+ *
+ * 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 THE AUTHORS OR COPYRIGHT HOLDERS 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.
+ *
+ * @section DESCRIPTION
+ *
+ * BMP085 I2C Temperature/Pressure/Altitude Sensor
+ *
+ * Max sample rate: 128 samples/second (temperature at 1/second)
+ *
+ * Datasheet:
+ *
+ * http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Pressure/BST-BMP085-DS000-06.pdf
+ */
+
+#ifndef BMP085_H
+#define BMP085_H
+
+#include "mbed.h"
+
+class BMP085
+{
+public:
+    /**
+     * The I2C address that can be passed directly to i2c object (it's already shifted 1 bit left).
+     */
+    static const int16_t I2C_ADDRESS = 0xEE; //address of bmp085
+
+    /**
+     * Constructor.
+     *
+     * Calls init function
+     *
+     * @param sda - mbed pin to use for the SDA I2C line.
+     * @param scl - mbed pin to use for the SCL I2C line.
+     */
+    BMP085(PinName sda, PinName scl);
+
+    /**
+    * Constructor that accepts external i2c interface object.
+    *
+    * Calls init function
+    *
+    * @param i2c The I2C interface object to use.
+    */
+    BMP085(I2C &i2c) : i2c_(i2c) {
+        init();
+    }
+    
+    ~BMP085();
+    
+    /**
+    * Sets the oss rate variables
+    * Acceptable values  = 1,2,4,8
+    *
+    *@param oss the number of over sampling
+    */
+    void set_oss(int oss);
+
+    int32_t get_temperature();
+    int32_t get_pressure();
+    double get_altitude_m();
+    double get_altitude_ft();
+    
+    /**
+    * Initialize sensor and get calibration values
+    */
+    void init();
+    
+    void display_cal_param(Serial *pc);
+
+protected:
+    
+
+private:
+
+    I2C &i2c_;
+
+    /**
+     * The raw buffer for allocating I2C object in its own without heap memory.
+     */
+    char i2cRaw[sizeof(I2C)];
+
+    // calculation variables
+    int16_t AC1, AC2, AC3, B1, B2, MB, MC, MD;
+    uint16_t  AC4, AC5, AC6;
+    
+    int32_t UT,UP; // uncompressed temperature and pressure value
+    
+    int32_t X1, X2, B5, temperature; // get_temperature variables
+    
+    int32_t B6, B3, X3, pressure; // get_pressure variables
+    uint32_t B4, B7;
+    
+    double altitude;
+    
+    // setting variables
+    char oss_bit_;
+    char oversampling_setting_;
+    float conversion_time_;
+
+    void get_cal_param(); // get calibration parameters
+    void get_ut(); // get uncompressed temperature
+    void get_up(); // get uncompressed pressure
+    void write_char(char,char);
+    int16_t read_int16(char);
+    uint16_t read_uint16(char);
+    void read_multiple(char, char*, int);
+};
+
+#endif
\ No newline at end of file

--- a/main.cpp	Mon Nov 05 19:31:55 2012 +0000
+++ b/main.cpp	Tue Nov 06 02:39:40 2012 +0000
@@ -1,248 +1,192 @@
-/*
-*
-*
-*
-* 1.8 - 3.6V (Vdd)
-* 1.62 - 3.6 (Vddio)
-*
-*
-*Altitude = 44330*(1-(p/p0)^(1/5.255))
-*   set p0 to sealevel pressure
-* delta p = 1hPa = 8.43m at sea level
-*
-*/
-
-/*
-*Pinout:
-*pin9  = SDA
-*pin10 = SCL
-*pin11 = XCLR (digital out; active low; Resets sensor)
-*pin12 = EOC ("end of conversation"; signal when conversion finished)
-*
-*
-*
-*/
-
-class BMP085
-{
-
-public:
-    BMP085();
-    //BMP085();
-    
-    float get_temperature();
-    long get_pressure();
-    void calculations(long);
-
-protected:
-    void init(BMP085_OSS);
-    unsigned short read_short (int, int);
-    void write_char (int, int, int);
-    
-    I2C i2c;
-    float temperature;
-    long pressure;
-    
-private:
-    short AC1, AC2, AC3, B1, B2, MB, MC, MD, OSS;
-    unsigned short  AC4, AC5, AC6;   
-};
-
-#include "mbed.h"
-
-enum bmp085_oss {ULTRALOW,  //samples 1 time
-                 STANDARD,  //samples twice
-                 HIGH,      //samples 4 times
-                 ULTRAHIGH};//samples 8 times
-
-
-I2C i2c(p9, p10); // sda, scl
-Serial pc(USBTX, USBRX); // tx, rx
-
-const int bmp085_address = 0xEE; //address of bmp085
-const int P0 = 101325; //pressure at sea level
-
-
-void bmp085_calibration(void);
-void display_calibration(void);
-unsigned short read_short(int,int);
-void write_char(int,int,int);
-
-long get_raw_temp(void);
-void calculations(long);
-
-float get_temperature(void);
-long get_pressure(void);
-float get_altitude(long);
-
-//short AC1, AC2, AC3, B1, B2, MB, MC, MD, OSS;
-//unsigned short  AC4, AC5, AC6;
-
-
-
-
-
-
-int main()
-{
-
-    //Initialize
-    OSS = STANDARD; //change between enums under bmp085_oss for desired Sampling resolution
-
-    //calibrate
-    bmp085_calibration();
-    display_calibration();
-
-    long raw_temp = get_raw_temp();
-
-    calculations(raw_temp);
-
-    //float altitude = get_altitude(pressure);
-
-    //pc.printf("Temperature: %f\n",temperature);
-    //pc.printf("Pressure: %l\n", pressure);
-    //pc.printf("Altitude: %f\n", altitude);
-
-
-}
-
-long get_raw_temp(void)
-{
-    long raw_temp;
-
-    //Read raw temperature value
-    write_char(bmp085_address, 0xF4, 0x2E);
-    wait_ms(4.5);
-    raw_temp = read_short(bmp085_address, 0xF6);
-
-    return raw_temp;
-}
-
-void calculations(long raw_temp)
-{
-    long X1, X2, B5; //temperature;
-
-    //Start temperature calculation
-    X1 = (((long)raw_temp - (long)AC6) * (long)AC5) >> 15;
-    X2 = ((long)MC << 11) / (X1 + MD);
-    B5 = X1 + X2;
-    temperature = ((B5 + 8) >> 4);
-
-    temperature = ((float)temperature / 10.0);
-
-    pc.printf("Temperature: %f\n",temperature);
-
-
-    long raw_pressure, B6, B3, X3;
-    unsigned long B4, B7;
-
-    //Read raw pressure value
-    write_char(bmp085_address, 0xf4, 0x34 | (OSS << 6));
-    wait_ms(5);
-    raw_pressure = read_short(bmp085_address, 0xF6) >> (8 - OSS);
-
-    //Start Pressure calculation
-    B6 = B5 - 4000;
-    X1 = (B2 * (B6 * B6) >> 12) >> 11;
-    X2 = (AC2 * B6) >> 11;
-    X3 = X1 + X2;
-    B3 = (((AC1 * 4 + X3) << OSS + 2) / 4);
-    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)(raw_pressure - B3) * (50000 >> OSS));
-    if (B7 < 0x80000000)
-        pressure = (B7 *2) / B4;
-    else
-        pressure = (B7 / B4) * 2;
-
-    X1 = (pressure >> 8) * (pressure >>8);
-    X1 = (X1 * 3038) >>16;
-    X2 = (-7357 * pressure) >>16;
-    pressure += (X1 + X2 + 3791)>>4;
-
-    pc.printf("Pressure: %f\n", pressure);
-
-}
-
-float get_temperature(void)
-{
-    return temperature;
-}
-
-long get_pressure(void)
-{
-    return pressure;
-}
-
-float get_altitude(long pressure)
-{
-    float altitude;
-
-    altitude = (float)44330 * (1 - pow(( pressure/P0), 0.190295));
-
-    pc.printf("Altitude: %f\n", altitude);
-    return altitude;
-
-}
-
-void bmp085_calibration(void)
-{
-    AC1 = read_short(bmp085_address, 0xAA);
-    AC2 = read_short(bmp085_address, 0xAC);
-    AC3 = read_short(bmp085_address, 0xAE);
-    AC4 = read_short(bmp085_address, 0xB0);
-    AC5 = read_short(bmp085_address, 0xB2);
-    AC6 = read_short(bmp085_address, 0xB4);
-    B1  = read_short(bmp085_address, 0xB6);
-    B2  = read_short(bmp085_address, 0xB8);
-    MB  = read_short(bmp085_address, 0xBA);
-    MC  = read_short(bmp085_address, 0xBC);
-    MD  = read_short(bmp085_address, 0xBE);
-
-}
-
-void display_calibration(void)
-{
-    pc.printf("Calibration Values:\n");
-    pc.printf("AC1 = %d\n",AC1);
-    pc.printf("AC2 = %d\n",AC2);
-    pc.printf("AC3 = %d\n",AC3);
-    pc.printf("AC4 = %d\n",AC4);
-    pc.printf("AC5 = %d\n",AC5);
-    pc.printf("AC6 = %d\n",AC6);
-    pc.printf("B1 = %d\n",B1);
-    pc.printf("B2 = %d\n",B2);
-    pc.printf("MB = %d\n",MB);
-    pc.printf("MC = %d\n",MC);
-    pc.printf("MD = %d\n",MD);
-}
-
-unsigned short read_short(int device_address,int address)
-{
-    unsigned short value;
-
-    i2c.start();
-    i2c.write(device_address);
-    i2c.write(address);
-
-    i2c.start();
-    i2c.write(device_address | 1);
-    value = i2c.read(1) << 8;
-    value |= i2c.read(0);
-    i2c.stop();
-
-    return value;
-
-}
-
-void write_char(int device_address, int address, int data)
-{
-    i2c.start();
-    i2c.write(device_address);
-    i2c.write(address);
-    i2c.write(data);
-    i2c.stop();
-}
-
+/*
+*
+* 1.8 - 3.6V (Vdd)
+* 1.62 - 3.6 (Vddio)
+*
+*
+*Altitude = 44330*(1-(p/p0)^(1/5.255))
+*   set p0 to sealevel pressure
+* delta p = 1hPa = 8.43m at sea level
+*
+*/
+
+/*
+*Pinout:
+*pin9  = SDA
+*pin10 = SCL
+*pin11 = XCLR (digital out; active low; Resets sensor)
+*pin12 = EOC ("end of conversation"; signal when conversion finished)
+*
+*/
+
+#include "mbed.h"
+#include "BMP085.h"
+
+I2C i2c(p9, p10); // sda, scl
+BMP085 alt_sensor(i2c);
+Serial pc(USBTX, USBRX); // tx, rx
+
+/*
+const int bmp085_address = 0xEE; //address of bmp085
+const int P0 = 101325; //pressure at sea level
+
+void bmp085_calibration(void);
+void display_calibration(void);
+unsigned short read_short(int,int);
+
+void write_char(int,int,int);
+
+long get_raw_temp(void);
+void calculations(long);
+
+float get_temperature(void);
+long get_pressure(void);
+float get_altitude(long);
+*/
+
+//short AC1, AC2, AC3, B1, B2, MB, MC, MD, OSS;
+//unsigned short  AC4, AC5, AC6;
+
+int main()
+{
+    pc.baud(9600);
+    //alt_sensor.display_cal_param(&pc);
+    while(1)
+    {
+        pc.printf("Temperature: %d\r\n", alt_sensor.get_temperature());
+        pc.printf("Pressure: %d\r\n", alt_sensor.get_pressure());
+        pc.printf("Altitude: %f\r\n", alt_sensor.get_altitude_ft());
+        
+        wait(0.5);
+    }
+    //Initialize
+    //OSS = STANDARD; //change between enums under bmp085_oss for desired Sampling resolution
+
+    //calibrate
+    //bmp085_calibration();
+    //display_calibration();
+
+    //long raw_temp = get_raw_temp();
+
+    //calculations(raw_temp);
+
+    //float altitude = get_altitude(pressure);
+
+    //pc.printf("Temperature: %f\n",temperature);
+    //pc.printf("Pressure: %l\n", pressure);
+    //pc.printf("Altitude: %f\n", altitude);
+}
+/*
+long get_raw_temp(void)
+{
+    long raw_temp;
+
+    //Read raw temperature value
+    write_char(bmp085_address, 0xF4, 0x2E);
+    wait_ms(4.5);
+    raw_temp = read_short(bmp085_address, 0xF6);
+
+    return raw_temp;
+}
+
+void calculations(long raw_temp)
+{
+    long X1, X2, B5; //temperature;
+
+    //Start temperature calculation
+    X1 = (((long)raw_temp - (long)AC6) * (long)AC5) >> 15;
+    X2 = ((long)MC << 11) / (X1 + MD);
+    B5 = X1 + X2;
+    temperature = ((B5 + 8) >> 4);
+
+    temperature = ((float)temperature / 10.0);
+
+    pc.printf("Temperature: %f\n",temperature);
+
+
+    long raw_pressure, B6, B3, X3;
+    unsigned long B4, B7;
+
+    //Read raw pressure value
+    write_char(bmp085_address, 0xf4, 0x34 | (OSS << 6));
+    wait_ms(5);
+    raw_pressure = read_short(bmp085_address, 0xF6) >> (8 - OSS);
+
+    //Start Pressure calculation
+    B6 = B5 - 4000;
+    X1 = (B2 * (B6 * B6) >> 12) >> 11;
+    X2 = (AC2 * B6) >> 11;
+    X3 = X1 + X2;
+    B3 = (((AC1 * 4 + X3) << OSS + 2) / 4);
+    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)(raw_pressure - B3) * (50000 >> OSS));
+    if (B7 < 0x80000000)
+        pressure = (B7 *2) / B4;
+    else
+        pressure = (B7 / B4) * 2;
+
+    X1 = (pressure >> 8) * (pressure >>8);
+    X1 = (X1 * 3038) >>16;
+    X2 = (-7357 * pressure) >>16;
+    pressure += (X1 + X2 + 3791)>>4;
+
+    pc.printf("Pressure: %f\n", pressure);
+
+}
+
+float get_temperature(void)
+{
+    return temperature;
+}
+
+long get_pressure(void)
+{
+    return pressure;
+}
+
+float get_altitude(long pressure)
+{
+    float altitude;
+
+    altitude = (float)44330 * (1 - pow(( pressure/P0), 0.190295));
+
+    pc.printf("Altitude: %f\n", altitude);
+    return altitude;
+
+}
+
+void bmp085_calibration(void)
+{
+    AC1 = read_short(bmp085_address, 0xAA);
+    AC2 = read_short(bmp085_address, 0xAC);
+    AC3 = read_short(bmp085_address, 0xAE);
+    AC4 = read_short(bmp085_address, 0xB0);
+    AC5 = read_short(bmp085_address, 0xB2);
+    AC6 = read_short(bmp085_address, 0xB4);
+    B1  = read_short(bmp085_address, 0xB6);
+    B2  = read_short(bmp085_address, 0xB8);
+    MB  = read_short(bmp085_address, 0xBA);
+    MC  = read_short(bmp085_address, 0xBC);
+    MD  = read_short(bmp085_address, 0xBE);
+
+}
+
+void display_calibration(void)
+{
+    pc.printf("Calibration Values:\n");
+    pc.printf("AC1 = %d\n",AC1);
+    pc.printf("AC2 = %d\n",AC2);
+    pc.printf("AC3 = %d\n",AC3);
+    pc.printf("AC4 = %d\n",AC4);
+    pc.printf("AC5 = %d\n",AC5);
+    pc.printf("AC6 = %d\n",AC6);
+    pc.printf("B1 = %d\n",B1);
+    pc.printf("B2 = %d\n",B2);
+    pc.printf("MB = %d\n",MB);
+    pc.printf("MC = %d\n",MC);
+    pc.printf("MD = %d\n",MD);
+}*/
+