WFS: Added water flow sensor without grove dependency

Signed-off-by: Sisinty Sasmita Patra <sisinty.s.patra@intel.com>

src/wfs/wfs.hpp

@@ -0,0 +1,140 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2015 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 <stdint.h>
+#include <sys/time.h>
+#include <mraa/gpio.h>
+
+namespace upm {
+
+  /**
+   * @brief Grove Water Flow Sensor library
+   * @defgroup wfs libupm-wfs
+   * @ingroup seeed gpio liquid eak
+   */
+
+  /**
+   * @library wfs
+   * @sensor wfs
+   * @comname Grove Water Flow Sensor
+   * @type liquid
+   * @man seeed
+   * @web http://www.seeedstudio.com/wiki/index.php?title=G1/2_Water_Flow_sensor
+   * @con gpio
+   * @kit eak
+
+   * @brief API for the Grove Water Flow Sensor
+   *
+   * This sensor is used to measure water flow in liters per
+   * minute (LPM). It incorporates a Hall Effect sensor. The UPM module
+   * defines an interrupt routine to be triggered on each low pulse,
+   * keeping count. This device requires a 10K pull-up resistor for
+   * the signal line (yellow wire). There is a schematic diagram on
+   * the SeeedStudio site (3/2015):
+   * http://www.seeedstudio.com/wiki/index.php?title=G1/2_Water_Flow_sensor
+   *
+   * However, be careful when wiring this up - the schematic appears to
+   * have a bug in it: the lower left connection of the signal line
+   * (yellow) to Vcc (red) should not be there. The sensor can work
+   * with this connection, but probably not for very long.
+   *
+   * @image html wfs.jpg
+   * @snippet wfs.cxx Interesting
+   */
+  class WFS {
+  public:
+    /**
+     * Grove Water Flow sensor constructor
+     *
+     * @param pin Digital pin to use
+     */
+    WFS(int pin);
+    /**
+     * WFS destructor
+     */
+    ~WFS();
+    /**
+     * Returns the number of milliseconds elapsed since initClock()
+     * was last called.
+     *
+     * @return Elapsed milliseconds
+     */
+    uint32_t getMillis();
+
+    /**
+     * Resets the clock
+     *
+     */
+    void initClock();
+
+    /**
+     * Resets the flow counter to 0. The flow counter should be
+     * stopped via stopFlowCounter() prior to calling this function.
+     *
+     */
+    void clearFlowCounter() { m_flowCounter = 0; };
+
+    /**
+     * Starts the flow counter
+     *
+     */
+    void startFlowCounter();
+
+    /**
+     * Stops the flow counter
+     *
+     */
+    void stopFlowCounter();
+
+    /**
+     * Gets the flow counter
+     *
+     * @return Flow counter
+     */
+    uint32_t flowCounter() { return m_flowCounter; };
+
+    /**
+     * Computes the flow rate in liters per minute (LPM)
+     *
+     * @return Computed flow rate
+     */
+    float flowRate();
+
+  private:
+    /**
+     * Flow interrupt service routine (ISR)
+     *
+     */
+    static void flowISR(void *ctx);
+
+    volatile uint32_t m_flowCounter;
+    struct timeval m_startTime;
+    mraa_gpio_context m_gpio;
+    bool m_isrInstalled;
+  };
+}
+
+