Moisture: Add C Src and Example

Changed from GroveMoisture.

Signed-off-by: Abhishek Malik <abhishek.malik@intel.com>

src/moisture/moisture.hpp

@@ -0,0 +1,82 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2014 Intel Corporation.
+ *
+ * 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.
+ */
+#pragma once
+
+#include <string>
+#include <mraa/aio.h>
+
+namespace upm {
+  /**
+   * @brief Moisture Sensor library
+   * @defgroup grovemoisture libupm-grovemoisture
+   * @ingroup seeed analog liquid eak hak
+   */
+
+  /**
+   * @library moisture
+   * @sensor moisture
+   * @comname Moisture Sensor
+   * @altname Grove Moisture Sensor
+   * @type liquid
+   * @man seeed
+   * @con analog
+   * @kit eak hak
+   *
+   * @brief API for the Moisture Sensor
+   *
+   * UPM module for the Moisture Sensor.
+   * This sensor can be used to detect the moisture content
+   * of soil or whether there is water around the sensor.
+   * As the moisture content increases, so does the value that is read.
+   * Note: this sensor is not designed to be left in soil
+   * nor to be used outdoors.
+   *
+   * @image html grovemoisture.jpg
+   * @snippet moisture.cxx Interesting
+   */
+  class Moisture {
+  public:
+    /**
+     * Analog moisture sensor constructor
+     *
+     * @param pin Analog pin to use
+     */
+    Moisture(int pin);
+    /**
+     * Moisture destructor
+     */
+    ~Moisture();
+    /**
+     * Gets the moisture value from the sensor
+     *
+     * @return Moisture reading
+     */
+    int value();
+
+  private:
+    mraa_aio_context m_aio;
+  };
+}
+
+