Revision 0:457832d52954, committed 2012-02-25

Comitter:

AdamGreen

Date:

Sat Feb 25 03:23:51 2012 +0000

Commit message:

Changed in this revision

diff -r 000000000000 -r 457832d52954 Anemometer.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Anemometer.cpp	Sat Feb 25 03:23:51 2012 +0000
@@ -0,0 +1,60 @@
+/* Copyright 2012 Adam Green (http://mbed.org/users/AdamGreen/)
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+/* Implementation of class to interface for anemometer sensor with Sparkfun Weather Meters: 
+    http://www.sparkfun.com/products/8942
+*/
+#include <mbed.h>
+#include "Anemometer.h"
+
+
+#define REV_PER_SECOND_TO_KMPH  2.4f
+
+
+CAnemometer::CAnemometer(PinName AnemometerPin, unsigned int IgnoreTimeForDebounceInMicroSeconds)
+    : CDebouncedFallingEdgeCounter(AnemometerPin, IgnoreTimeForDebounceInMicroSeconds)
+{
+    m_CurrentWindSpeed = 0.0f;
+    ResetMaximumWindSpeed();
+    m_OneSecondTicker.attach_us<CAnemometer>(this, &CAnemometer::OneSecondTickerISR, 1000000);
+}
+
+
+void CAnemometer::ResetMaximumWindSpeed()
+{
+    m_MaximumWindSpeed = m_CurrentWindSpeed;
+}
+
+
+void CAnemometer::OneSecondTickerISR()
+{
+    unsigned int GetCurrentCount = GetCountAndZero();
+    
+    m_CurrentWindSpeed = (float)GetCurrentCount * REV_PER_SECOND_TO_KMPH;
+    if (m_CurrentWindSpeed > m_MaximumWindSpeed)
+    {
+        m_MaximumWindSpeed = m_CurrentWindSpeed;
+    }
+}
+
+float CAnemometer::GetCurrentWindSpeed()
+{
+    return m_CurrentWindSpeed;
+}
+
+
+float CAnemometer::GetMaximumWindSpeed()
+{
+    return m_MaximumWindSpeed;
+}

diff -r 000000000000 -r 457832d52954 Anemometer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Anemometer.h	Sat Feb 25 03:23:51 2012 +0000
@@ -0,0 +1,48 @@
+/* Copyright 2012 Adam Green (http://mbed.org/users/AdamGreen/)
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+/* Header file for class to interface with anemometer sensor of Sparkfun Weather Meters: 
+    http://www.sparkfun.com/products/8942
+*/
+#ifndef _ANEMOMETER_H_
+#define _ANEMOMETER_H_
+
+#include "DebouncedFallingEdgeCounter.h"
+
+
+namespace AFP
+{
+
+class CAnemometer : protected CDebouncedFallingEdgeCounter
+{
+protected:
+    Ticker          m_OneSecondTicker;
+    float           m_CurrentWindSpeed;
+    float           m_MaximumWindSpeed;
+
+public:
+    CAnemometer(PinName AnemometerPin, unsigned int IgnoreTimeForDebounceInMicroSeconds = 1000);
+    
+    float GetCurrentWindSpeed();
+    float GetMaximumWindSpeed();
+    void  ResetMaximumWindSpeed();
+
+protected:
+    void OneSecondTickerISR();
+};
+
+} // namespace AFP
+using namespace AFP;
+
+#endif // _ANEMOMETER_H_

diff -r 000000000000 -r 457832d52954 DebouncedFallingEdgeCounter.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DebouncedFallingEdgeCounter.cpp	Sat Feb 25 03:23:51 2012 +0000
@@ -0,0 +1,100 @@
+/* Copyright 2012 Adam Green (http://mbed.org/users/AdamGreen/)
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+/* Implementation for wrapper class of InterruptIn used for counting falling edge
+   events with specified hold off time for the purpose of debouncing.
+*/
+#include <mbed.h>
+#include "DebouncedFallingEdgeCounter.h"
+
+
+CDebouncedFallingEdgeCounter::CDebouncedFallingEdgeCounter(PinName InterruptInPin, unsigned int IgnoreTimeForDebounceInMicroSeconds) 
+    : m_FallingEdgeInterruptIn(InterruptInPin)
+{
+    m_Timer.start();
+    m_IgnoreTimeForDebounce = IgnoreTimeForDebounceInMicroSeconds;
+    InitLastFallingEdgeTime();
+
+    ZeroCount();
+
+    m_FallingEdgeInterruptIn.mode(PullUp);
+    m_FallingEdgeInterruptIn.fall<CDebouncedFallingEdgeCounter>(this, &CDebouncedFallingEdgeCounter::FallingEdgeISR);
+}
+
+
+void CDebouncedFallingEdgeCounter::InitLastFallingEdgeTime()
+{
+    InitLastFallingEdgeTime((unsigned int)m_Timer.read_us());
+}
+
+
+void CDebouncedFallingEdgeCounter::InitLastFallingEdgeTime(unsigned int CurrentTime)
+{
+    m_LastFallingEdgeTime = CurrentTime - m_IgnoreTimeForDebounce;
+}
+
+
+void CDebouncedFallingEdgeCounter::FallingEdgeISR()
+{
+    // UNDONE: Can I just use whatever timer the m_Timer uses under the covers?
+    unsigned int CurrentTime = (unsigned int)m_Timer.read_us();
+    
+    if (TimeSinceLastFallingEdge(CurrentTime) >= m_IgnoreTimeForDebounce)
+    {
+        m_FallingEdgeCount++;
+        m_LastFallingEdgeTime = CurrentTime;
+    }
+}
+
+
+unsigned int CDebouncedFallingEdgeCounter::TimeSinceLastFallingEdge(unsigned int CurrentTime)
+{
+    return CurrentTime - m_LastFallingEdgeTime;
+}
+
+
+unsigned int CDebouncedFallingEdgeCounter::GetCountAndZero()
+{
+    unsigned int CurrentCount;
+    
+    CurrentCount = GetCount();
+    ZeroCount();
+    return CurrentCount;
+}
+
+
+unsigned int CDebouncedFallingEdgeCounter::GetCount()
+{
+    RefreshTimers();
+    
+    return m_FallingEdgeCount;
+}
+
+
+void CDebouncedFallingEdgeCounter::ZeroCount()
+{
+    m_FallingEdgeCount = 0;
+}
+
+
+void CDebouncedFallingEdgeCounter::RefreshTimers()
+{
+    unsigned int CurrentTime = (unsigned int)m_Timer.read_us();
+    
+    if (TimeSinceLastFallingEdge(CurrentTime) > m_IgnoreTimeForDebounce)
+    {
+        // Protect from timer overflow.
+        InitLastFallingEdgeTime(CurrentTime);
+    }
+}

diff -r 000000000000 -r 457832d52954 DebouncedFallingEdgeCounter.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DebouncedFallingEdgeCounter.h	Sat Feb 25 03:23:51 2012 +0000
@@ -0,0 +1,52 @@
+/* Copyright 2012 Adam Green (http://mbed.org/users/AdamGreen/)
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+/* Header file for wrapper class of InterruptIn used for counting falling edge
+   events with specified hold off time for the purpose of debouncing.
+*/
+#ifndef _DEBOUNCED_FALLING_EDGE_COUNT_H_
+#define _DEBOUNCED_FALLING_EDGE_COUNT_H_
+
+namespace AFP
+{
+
+class CDebouncedFallingEdgeCounter
+{
+protected:
+    InterruptIn     m_FallingEdgeInterruptIn;
+    // UNDONE: Run for over 30 minutes and make sure that this rolls over as expected.
+    Timer           m_Timer;
+    unsigned int    m_IgnoreTimeForDebounce;
+    unsigned int    m_LastFallingEdgeTime;
+    unsigned int    m_FallingEdgeCount;
+
+public:
+    CDebouncedFallingEdgeCounter(PinName InterruptInPin, unsigned int IgnoreTimeForDebounceInMicroSeconds);
+    
+    unsigned int GetCountAndZero();
+    void         ZeroCount();
+    unsigned int GetCount();
+
+protected:
+    void          InitLastFallingEdgeTime();
+    void          InitLastFallingEdgeTime(unsigned int CurrentTime);
+    void          FallingEdgeISR();
+    void          RefreshTimers();
+    unsigned int  TimeSinceLastFallingEdge(unsigned int CurrentTime);
+};
+
+} // namespace AFP
+using namespace AFP;
+
+#endif // _DEBOUNCED_FALLING_EDGE_COUNT_H_

diff -r 000000000000 -r 457832d52954 RainGauge.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RainGauge.h	Sat Feb 25 03:23:51 2012 +0000
@@ -0,0 +1,52 @@
+/* Copyright 2012 Adam Green (http://mbed.org/users/AdamGreen/)
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+/* Header file for class to interface with the rain gauge sensor of the Sparkfun Weather Meters: 
+    http://www.sparkfun.com/products/8942
+*/
+#ifndef _RAIN_GAUGE_H_
+#define _RAIN_GAUGE_H_
+
+#include "DebouncedFallingEdgeCounter.h"
+
+
+#define MILLIMETERS_OF_RAIN_PER_COUNT 0.2794f
+
+
+namespace AFP
+{
+
+class CRainGauge : protected CDebouncedFallingEdgeCounter
+{
+public:
+    CRainGauge(PinName RainGaugePin, unsigned int IgnoreTimeForDebounceInMicroSeconds = 1000)
+        : CDebouncedFallingEdgeCounter(RainGaugePin, IgnoreTimeForDebounceInMicroSeconds)
+    {
+    }
+    
+    void  Reset()
+    {
+        ZeroCount();
+    }
+    
+    float GetRainfall()
+    {
+        return (float)GetCount() * MILLIMETERS_OF_RAIN_PER_COUNT;
+    }
+};
+
+} // namespace AFP
+using namespace AFP;
+
+#endif // _RAIN_GAUGE_H_

diff -r 000000000000 -r 457832d52954 WeatherMeters.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WeatherMeters.cpp	Sat Feb 25 03:23:51 2012 +0000
@@ -0,0 +1,59 @@
+/* Copyright 2012 Adam Green (http://mbed.org/users/AdamGreen/)
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+/* Implementation of class to interface with Sparkfun Weather Meters: 
+    http://www.sparkfun.com/products/8942
+*/
+#include <mbed.h>
+#include "WeatherMeters.h"
+
+
+CWeatherMeters::CWeatherMeters(PinName AnemometerPin,
+                               PinName RainGaugePin,
+                               PinName WindVanePin,
+                               float   WindVaneSeriesResistance) : m_Anemometer(AnemometerPin),
+                                                                   m_RainGauge(RainGaugePin),
+                                                                   m_WindVane(WindVanePin, WindVaneSeriesResistance)
+{
+}
+
+
+void CWeatherMeters::GetMeasurements(SMeasurements* pMeasurements)
+{
+    pMeasurements->WindDirectionString = m_WindVane.GetWindDirectionAsString();
+    pMeasurements->WindDirectionAngle  = m_WindVane.GetWindDirectionAsAngle();
+    pMeasurements->WindSpeed = m_Anemometer.GetCurrentWindSpeed();
+    pMeasurements->MaximumWindSpeed = m_Anemometer.GetMaximumWindSpeed();
+    pMeasurements->Rainfall = m_RainGauge.GetRainfall();
+}
+
+
+void CWeatherMeters::Reset()
+{
+    ResetRainfall();
+    ResetMaximumWindSpeed();
+}
+    
+    
+void CWeatherMeters::ResetRainfall()
+{
+    m_RainGauge.Reset();
+}
+    
+
+void CWeatherMeters::ResetMaximumWindSpeed()
+{
+    m_Anemometer.ResetMaximumWindSpeed();
+}
+

diff -r 000000000000 -r 457832d52954 WeatherMeters.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WeatherMeters.h	Sat Feb 25 03:23:51 2012 +0000
@@ -0,0 +1,130 @@
+/* Copyright 2012 Adam Green (http://mbed.org/users/AdamGreen/)
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+/* Header file for class to interface with Sparkfun Weather Meters: 
+    http://www.sparkfun.com/products/8942
+*/
+#ifndef _WEATHER_METERS_H_
+#define _WEATHER_METERS_H_
+
+#include "WindVane.h"
+#include "RainGauge.h"
+#include "Anemometer.h"
+
+
+namespace AFP
+{
+
+/** A class to interface with the Sparkfun Weather Meters.
+    http://www.sparkfun.com/products/8942
+    
+    This set of weather meters from Sparkfun includes anemometer (wind speed),
+    wind vane, and rain gauge.  All of the sensors use reed switches so that
+    the electronics can detect motion/location in the sensor hardware via 
+    magnets placed in the sensors without actually exposing the electonic
+    switches themselves to the elements.  A reed switch closes as the 
+    anemometer spins and the rain gauge empties.  The wind vane includes 
+    8 reed switches, each with a different valued resistor attached so that
+    the voltage will vary depending on where the magnet in the vane is
+    located.
+ * Example:
+ * @code
+#include <mbed.h>
+#include "WeatherMeters.h"
+
+int main() 
+{
+    CWeatherMeters WeatherMeters(p9, p10, p15);
+    for (;;)
+    {
+        CWeatherMeters::SMeasurements   Measurements;
+        
+        WeatherMeters.GetMeasurements(&Measurements);
+        
+        printf("Direction: %s\n", Measurements.WindDirectionString);
+        printf("Depth: %f\n",Measurements.Rainfall);
+        printf("Current speed: %f\n", Measurements.WindSpeed);
+        printf("Maximum speed: %f\n", Measurements.MaximumWindSpeed);
+
+        wait(1.0f);
+    }
+}
+ * @endcode
+ */
+class CWeatherMeters
+{
+protected:
+    CAnemometer     m_Anemometer;
+    CRainGauge      m_RainGauge;
+    CWindVane       m_WindVane;
+
+public:
+     /** A structure in which the current measurements registered by the weather
+         meters are returned from the GetMeasurements() method.
+     */
+     struct SMeasurements
+     {
+        const char* WindDirectionString;    /**< String representing current wind direction.  Example: "North" */
+        float       WindDirectionAngle;     /**< Wind direction in degrees from north. */
+        float       WindSpeed;              /**< Current wind speed in km/hour. */
+        float       MaximumWindSpeed;       /**< Maximum wind speed measured since last reset.  Measured in km/hour. */
+        float       Rainfall;               /**< Amount of rainfall since last reset.  Measured in mm. */
+     };
+     
+     /** Create a CWeatherMeters object, binds it to the specified input pins,
+         and initializes the required interrupt handlers.
+         
+         @param AnemometerPin The mbed pin which is connected to the anemometer
+                sensor.  Must be a pin on which the mbed supports InterruptIn.
+         @param RainGauagePin The mbed pin which is connected to the rain gauge
+                sensor.  Must be a pin on which the mbed supports InterruptIn.
+         @param WindVanePin The mbed pin which is connected to the wind vane
+                sensor.  Must be a pin on which the mbed supports AnalogIn.
+         @param WindVaneSeriesResistance The value of the resistance which is
+                in series with the wind vane sensor and along with the
+                varying resistance of the wind vane sensor itself, acts as a
+                voltage divider.
+    */
+    CWeatherMeters(PinName AnemometerPin,
+                   PinName RainGaugePin,
+                   PinName WindVanePin,
+                   float   WindVaneSeriesResistance = 10000.0f);
+    
+    /** Gets current weather meter measurements.
+    
+        NOTE: Should call this method on a regular basis (every 15 minutes or 
+        less) to keep internal timers from overflowing.
+    
+     @param pMeasurements points to the measurement structure to be filled in
+            with the current measurement from the sensors.  The historical
+            values in this structure such as rainfall and maximum wind
+            speed can be reset by calls to ResetRainfall(), 
+            ResetMaximumWindSpeed(), and Reset().
+    */
+    void GetMeasurements(SMeasurements* pMeasurements);
+    
+    /** Resets all historical measurements: rainfall and maximum wind speed. */
+    void Reset();
+    
+    /** Resets the cumulative rainfall measurement. */
+    void ResetRainfall();
+    
+    /** Resets the maximum wind speed measurement. */
+    void ResetMaximumWindSpeed();
+};
+
+} // namespace AFP
+using namespace AFP;
+
+#endif // _WEATHER_METERS_H_

diff -r 000000000000 -r 457832d52954 WindVane.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WindVane.cpp	Sat Feb 25 03:23:51 2012 +0000
@@ -0,0 +1,96 @@
+/* Copyright 2012 Adam Green (http://mbed.org/users/AdamGreen/)
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+/* Declaration of class to interface with wind vane sensor Sparkfun Weather Meters: 
+    http://www.sparkfun.com/products/8942
+*/
+#include <mbed.h>
+#include "WindVane.h"
+
+
+#define REV_PER_SECOND_TO_KMPH  2.4f
+#define PARALLEL_R(R1, R2) (((R1) * (R2)) / ((R1) + (R2)))
+#define ARRAY_SIZE(X) (sizeof(X)/sizeof(X[0]))
+
+struct SDescription
+{
+    const char* DirectionString;
+    float       DirectionAngle;
+    float       SensorResistance;
+};
+
+
+static SDescription g_WindVaneDescriptionTable[16] = {
+    { "North",            0.0f,  33.0f * 1000.0f },
+    { "North North East", 22.5f, PARALLEL_R(33.0f * 1000.0f, 8.2f * 1000.0f) },
+    { "North East",       45.0f, 8.2f * 1000.0f },
+    { "East North East",  67.5f, PARALLEL_R(8.2f * 1000.0f, 1000.0f) },
+    { "East",             90.0f, 1000.0f },
+    { "East South East",  112.5f, PARALLEL_R(1000.0f, 2.2f * 1000.0f) },
+    { "South East",       135.0f, 2.2f * 1000.0f },
+    { "South South East", 157.5f, PARALLEL_R(2.2f * 1000.0f, 3.9f * 1000.0f) },
+    { "South",            180.0f, 3.9f * 1000.0f },
+    { "South South West", 202.5f, PARALLEL_R(3.9f * 1000.0f, 16.0f * 1000.0f) },
+    { "South West",       225.0f, 16.0f * 1000.0f },
+    { "West South West",  247.5f, PARALLEL_R(16.0f * 1000.0f, 120.0f * 1000.0f) },
+    { "West",             270.0f, 120.0f * 1000.0f },
+    { "West North West",  292.5f, PARALLEL_R(120.0f * 1000.0f, 64.9f * 1000.0f) },
+    { "North West",       315.0f, 64.9f * 1000.0f },
+    { "North North West", 337.5f, PARALLEL_R(64.9f * 1000.0f, 33.0f * 1000.0f) }
+};
+
+
+CWindVane::CWindVane(PinName WindVanePin, float WindVaneSeriesResistance)
+    : m_WindVaneAnalogIn(WindVanePin)
+{
+    for (size_t i = 0 ; i < ARRAY_SIZE(g_WindVaneDescriptionTable) ; i++)
+    {
+        SDescription* pDescription = &g_WindVaneDescriptionTable[i];
+
+        m_WindVaneVoltageTable[i] = pDescription->SensorResistance /
+                                    (pDescription->SensorResistance + WindVaneSeriesResistance);
+    }
+}
+
+const char* CWindVane::GetWindDirectionAsString()
+{
+    return g_WindVaneDescriptionTable[DetermineWindDirectionIndex()].DirectionString;
+}
+
+float CWindVane::GetWindDirectionAsAngle()
+{
+    return g_WindVaneDescriptionTable[DetermineWindDirectionIndex()].DirectionAngle;
+}
+
+size_t CWindVane::DetermineWindDirectionIndex()
+{
+    float WindVaneSensorVoltage = m_WindVaneAnalogIn.read();
+
+    // Default to the first entry being closest.
+    size_t ClosestIndex = 0;
+    float  ClosestDelta = fabs(m_WindVaneVoltageTable[0] - WindVaneSensorVoltage);
+    
+    // Walk the rest of the entries to see if there is another which is closer.
+    for (size_t i = 1 ; i < ARRAY_SIZE(m_WindVaneVoltageTable) ; i++)
+    {
+        float Delta = fabs(m_WindVaneVoltageTable[i] - WindVaneSensorVoltage);
+        if (Delta < ClosestDelta)
+        {
+            ClosestDelta = Delta;
+            ClosestIndex = i;
+        }
+    }
+    
+    return ClosestIndex;
+}

diff -r 000000000000 -r 457832d52954 WindVane.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WindVane.h	Sat Feb 25 03:23:51 2012 +0000
@@ -0,0 +1,43 @@
+/* Copyright 2012 Adam Green (http://mbed.org/users/AdamGreen/)
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+/* Implementation of class to interface with wind vane sensor Sparkfun Weather Meters: 
+    http://www.sparkfun.com/products/8942
+*/
+#ifndef _WIND_VANE_H_
+#define _WIND_VANE_H_
+
+namespace AFP
+{
+
+class CWindVane
+{
+protected:
+    AnalogIn            m_WindVaneAnalogIn;
+    float               m_WindVaneVoltageTable[16];
+
+public:
+    CWindVane(PinName WindVanePin, float WindVaneSeriesResistance = 10000.0f);
+    
+    const char* GetWindDirectionAsString();
+    float       GetWindDirectionAsAngle();
+    
+protected:
+    size_t      DetermineWindDirectionIndex();
+};
+
+} // namespace AFP
+using namespace AFP;
+
+#endif // _WIND_VANE_H_