LED: Added C Src and Example

Changed from Grove LED to LED.

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

src/led/led.cxx

@@ -0,0 +1,67 @@
+/*
+ * Authors: Brendan Le Foll <brendan.le.foll@intel.com>
+ *          Mihai Tudor Panu <mihai.tudor.panu@intel.com>
+ *          Sarah Knepper <sarah.knepper@intel.com>
+ * 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
+ * "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 <iostream>
+#include <string>
+#include <stdexcept>
+
+#include "led.hpp"
+
+using namespace std;
+using namespace upm;
+
+Led::Led(int 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_OUT);
+}
+
+Led::~Led()
+{
+    mraa_gpio_close(m_gpio);
+}
+
+mraa_result_t Led::write(int value)
+{
+    if (value >= 1) {
+        return mraa_gpio_write(m_gpio, 1);
+    }
+    return mraa_gpio_write(m_gpio, 0);
+}
+
+mraa_result_t Led::on()
+{
+    return write(1);
+}
+
+mraa_result_t Led::off()
+{
+    return write(0);
+}