linefinder: C implementation; FTI; C++ wraps C

Signed-off-by: Jon Trulson <jtrulson@ics.com>

examples/c/CMakeLists.txt

@@ -128,6 +128,7 @@ add_example (lm35)
 add_example (rotaryencoder)
 add_example (rpr220)
 add_example (md)
+add_example (linefinder)
 
 # Custom examples
 add_custom_example (nmea_gps_i2c-example-c nmea_gps_i2c.c nmea_gps)

examples/c/linefinder.c

@@ -0,0 +1,72 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 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.
+ */
+
+#include <unistd.h>
+#include <stdio.h>
+#include <signal.h>
+
+#include <upm_utilities.h>
+#include "linefinder.h"
+
+int shouldRun = true;
+
+void sig_handler(int signo)
+{
+  if (signo == SIGINT)
+    shouldRun = false;
+}
+
+
+int main ()
+{
+    signal(SIGINT, sig_handler);
+
+//! [Interesting]
+    // Instantiate a  Line Finder sensor on digital pin D2
+    linefinder_context sensor = linefinder_init(2);
+
+    if (!sensor)
+    {
+        printf("linefinder_init() failed\n");
+        return 1;
+    }
+
+    // check every second for the presence of white or black detection
+    while (shouldRun)
+    {
+        if (linefinder_white_detected(sensor))
+            printf("White detected.\n");
+        else
+            printf("Black detected.\n");
+
+        upm_delay(1);
+    }
+
+    printf("Exiting...\n");
+
+    linefinder_close(sensor);
+
+//! [Interesting]
+    return 0;
+}

src/linefinder/CMakeLists.txt

@@ -1,5 +1,9 @@
 upm_mixed_module_init (NAME linefinder
     DESCRIPTION "Infrared (IR) based line finder"
+    C_HDR linefinder.h
+    C_SRC linefinder.c
     CPP_HDR linefinder.hpp
     CPP_SRC linefinder.cxx
+    FTI_SRC linefinder_fti.c
+    CPP_WRAPS_C
     REQUIRES mraa)

src/linefinder/linefinder.c

@@ -0,0 +1,84 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 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.
+ */
+
+#include <assert.h>
+
+#include "linefinder.h"
+
+linefinder_context linefinder_init(int pin)
+{
+    linefinder_context dev =
+        (linefinder_context)malloc(sizeof(struct _linefinder_context));
+
+    if (!dev)
+        return NULL;
+
+    dev->gpio = NULL;
+
+    // make sure MRAA is initialized
+    int mraa_rv;
+    if ((mraa_rv = mraa_init()) != MRAA_SUCCESS)
+    {
+        printf("%s: mraa_init() failed (%d).\n", __FUNCTION__, mraa_rv);
+        linefinder_close(dev);
+        return NULL;
+    }
+
+    // MRAA contexts...
+    if ( !(dev->gpio = mraa_gpio_init(pin)) )
+    {
+        printf("%s: mraa_gpio_init() failed\n",
+               __FUNCTION__);
+        linefinder_close(dev);
+        return NULL;
+    }
+
+    mraa_gpio_dir(dev->gpio, MRAA_GPIO_IN);
+
+    return dev;
+}
+
+void linefinder_close(linefinder_context dev)
+{
+    assert(dev != NULL);
+
+    if (dev->gpio)
+        mraa_gpio_close(dev->gpio);
+
+    free(dev);
+}
+
+bool linefinder_white_detected(const linefinder_context dev)
+{
+    assert(dev != NULL);
+
+    return (!mraa_gpio_read(dev->gpio) ? true : false);
+}
+
+bool linefinder_black_detected(const linefinder_context dev)
+{
+    assert(dev != NULL);
+
+    return (mraa_gpio_read(dev->gpio) ? true : false);
+}

src/linefinder/linefinder.cxx

@@ -1,6 +1,6 @@
 /*
  * Author: Jon Trulson <jtrulson@ics.com>
- * Copyright (c) 2014 Intel Corporation.
+ * Copyright (c) 2014-2016 Intel Corporation.
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -31,29 +31,25 @@
 using namespace upm;
 using namespace std;
 
-LineFinder::LineFinder(int pin)
+LineFinder::LineFinder(int pin) :
+    m_linefinder(linefinder_init(pin))
 {
-  if ( !(m_gpio = mraa_gpio_init(pin)) )
-    {
-      throw std::invalid_argument(std::string(__FUNCTION__) +
-                                  ": mraa_gpio_init() failed, invalid pin?");
-      return;
-    }
-
-  mraa_gpio_dir(m_gpio, MRAA_GPIO_IN);
+  if (!m_linefinder)
+      throw std::runtime_error(std::string(__FUNCTION__) +
+                               ": linefinder_init() failed");
 }
 
 LineFinder::~LineFinder()
 {
-  mraa_gpio_close(m_gpio);
+    linefinder_close(m_linefinder);
 }
 
 bool LineFinder::whiteDetected()
 {
-  return (!mraa_gpio_read(m_gpio) ? true : false);
+    return linefinder_white_detected(m_linefinder);
 }
 
 bool LineFinder::blackDetected()
 {
-  return (mraa_gpio_read(m_gpio) ? true : false);
+    return linefinder_black_detected(m_linefinder);
 }

src/linefinder/linefinder.h

@@ -0,0 +1,77 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 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 <stdlib.h>
+#include <stdio.h>
+#include <upm.h>
+
+#include <mraa/gpio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+    /**
+     * Device context
+     */
+    typedef struct _linefinder_context {
+        mraa_gpio_context gpio;
+    } *linefinder_context;
+
+    /**
+     *  Line Finder inititialization
+     *
+     * @param pin Digital pin to use
+     * @return device context
+     */
+    linefinder_context linefinder_init(int pin);
+
+    /**
+     * LineFinder close
+     *
+     * @param Device context
+     */
+    void linefinder_close(linefinder_context dev);
+
+    /**
+     * Determines whether white has been detected
+     *
+     * @param Device context
+     * @return True if white is detected
+     */
+    bool linefinder_white_detected(const linefinder_context dev);
+
+    /**
+     * Determines whether black has been detected
+     *
+     * @param Device context
+     * @return True if black is detected
+     */
+    bool linefinder_black_detected(const linefinder_context dev);
+
+
+#ifdef __cplusplus
+}
+#endif

src/linefinder/linefinder.hpp

@@ -1,6 +1,6 @@
 /*
  * Author: Jon Trulson <jtrulson@ics.com>
- * Copyright (c) 2014 Intel Corporation.
+ * Copyright (c) 2014-2016 Intel Corporation.
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -23,63 +23,65 @@
  */
 #pragma once
 
-#include <string>
-#include <mraa/gpio.h>
+#include <linefinder.h>
 
 namespace upm {
-  /**
-   * @brief Line Finder Sensor library
-   * @defgroup linefinder libupm-linefinder
-   * @ingroup seeed dfrobot gpio color robok
-   */
+    /**
+     * @brief Line Finder Sensor library
+     * @defgroup linefinder libupm-linefinder
+     * @ingroup seeed dfrobot gpio color robok
+     */
 
-  /**
-   * @library linefinder
-   * @sensor linefinder
-   * @comname Line Finder
-   * @altname Grove Line Finder, DFRobot Line Tracking sensor
-   * @type color
-   * @man seeed, dfrobot
-   * @con gpio
-   * @kit robok
-   *
-   * @brief API for the  Line Finder Sensor
-   *
-   * UPM module for the Line Finder sensor. It outputs a
-   * digital signal indicating whether it is detecting black on a
-   * white background, or white on a black background.
-   *
-   * @image html linefinder.jpg
-   * @snippet linefinder.cxx Interesting
-   */
-  class LineFinder {
-  public:
     /**
-     *  Line Finder digital sensor constructor
+     * @library linefinder
+     * @sensor linefinder
+     * @comname Line Finder
+     * @altname Grove Line Finder, DFRobot Line Tracking sensor
+     * @type color
+     * @man seeed, dfrobot
+     * @con gpio
+     * @kit robok
      *
-     * @param pin Digital pin to use
-     */
-    LineFinder(int pin);
-    /**
-     * LineFinder destructor
-     */
-    ~LineFinder();
-    /**
-     * Determines whether white has been detected
+     * @brief API for the  Line Finder Sensor
      *
-     * @return True if white is detected
-     */
-    bool whiteDetected();
-    /**
-     * Determines whether black has been detected
+     * UPM module for the Line Finder sensor. It outputs a
+     * digital signal indicating whether it is detecting black on a
+     * white background, or white on a black background.
      *
-     * @return True if black is detected
+     * @image html linefinder.jpg
+     * @snippet linefinder.cxx Interesting
      */
-    bool blackDetected();
+    class LineFinder {
+    public:
+        /**
+         *  Line Finder digital sensor constructor
+         *
+         * @param pin Digital pin to use
+         */
+        LineFinder(int pin);
 
-  private:
-    mraa_gpio_context m_gpio;
-  };
+        /**
+         * LineFinder destructor
+         */
+        ~LineFinder();
+
+        /**
+         * Determines whether white has been detected
+         *
+         * @return True if white is detected
+         */
+        bool whiteDetected();
+
+        /**
+         * Determines whether black has been detected
+         *
+         * @return True if black is detected
+         */
+        bool blackDetected();
+
+    private:
+        linefinder_context m_linefinder;
+    };
 }
 
 

src/linefinder/linefinder_fti.c

@@ -0,0 +1,94 @@
+/*
+ * Author: Jon Trulson <jtrulson@ics.com>
+ * Copyright (c) 2016 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.
+ */
+
+#include "linefinder.h"
+#include <upm_fti.h>
+
+/**
+ * This file implements the Function Table Interface (FTI) for this sensor
+ */
+
+const char upm_linefinder_name[] = "LINEFINDER";
+const char upm_linefinder_description[] = "Line Finder";
+const upm_protocol_t upm_linefinder_protocol[] = {UPM_GPIO};
+const upm_sensor_t upm_linefinder_category[] = {UPM_BINARY};
+
+// forward declarations
+const void* upm_linefinder_get_ft(upm_sensor_t sensor_type);
+void* upm_linefinder_init_name();
+void upm_linefinder_close(void *dev);
+upm_result_t upm_linefinder_black_detected(void *dev, bool *value);
+
+const upm_sensor_descriptor_t upm_linefinder_get_descriptor()
+{
+    upm_sensor_descriptor_t usd;
+    usd.name = upm_linefinder_name;
+    usd.description = upm_linefinder_description;
+    usd.protocol_size = 1;
+    usd.protocol = upm_linefinder_protocol;
+    usd.category_size = 1;
+    usd.category = upm_linefinder_category;
+    return usd;
+}
+
+static const upm_sensor_ft ft =
+{
+  .upm_sensor_init_name = upm_linefinder_init_name,
+  .upm_sensor_close = upm_linefinder_close,
+};
+
+static const upm_binary_ft bft =
+{
+  .upm_binary_get_value = upm_linefinder_black_detected,
+};
+
+const void* upm_linefinder_get_ft(upm_sensor_t sensor_type)
+{
+  switch(sensor_type)
+    {
+    case UPM_SENSOR:
+      return &ft;
+    case UPM_BINARY:
+      return &bft;
+    default:
+      return NULL;
+    }
+}
+
+void *upm_linefinder_init_name()
+{
+  return NULL;
+}
+
+void upm_linefinder_close(void *dev)
+{
+  linefinder_close((linefinder_context)dev);
+}
+
+upm_result_t upm_linefinder_black_detected(void *dev, bool *value)
+{
+  *value = linefinder_black_detected((linefinder_context)dev);
+
+  return UPM_SUCCESS;
+}