examples: Handle additional example dependencies

Dependencies added via 'TARGETS' in add_example are 'in addition to' the
dependency provided by the example filename.

    * Small change to examples/CMakeLists.txt to handle additional
      dependencies
    * Prefix 'interfaces-' onto the interfaces examples

Signed-off-by: Noel Eck <noel.eck@intel.com>

examples/c++/interfaces-pressuresensor.cxx

@@ -0,0 +1,81 @@
+/*
+ * Author: Henry Bruce <henry.bruce@intel.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.
+ */
+
+#include <unistd.h>
+#include <iostream>
+#include "bmpx8x.hpp"
+#include "bme280.hpp"
+
+
+#define EDISON_I2C_BUS 1 
+#define FT4222_I2C_BUS 0
+
+//! [Interesting]
+// Simple example of using ILightSensor to determine 
+// which sensor is present and return its name.
+// ILightSensor is then used to get readings from sensor
+
+
+upm::IPressureSensor* getPressureSensor()
+{
+   upm::IPressureSensor* pressureSensor = NULL;
+   try {
+	pressureSensor = new upm::BME280 (mraa_get_sub_platform_id(FT4222_I2C_BUS));
+	return pressureSensor ;
+   } catch (std::exception& e)
+   {
+	std::cerr <<"BME280: "<<e.what() << std::endl;
+   }
+
+   try {
+      pressureSensor = new upm::BMPX8X(EDISON_I2C_BUS);
+      return pressureSensor;
+   } catch (std::exception& e) {
+      std::cerr << "BMPX8X: " << e.what() << std::endl;      
+   }
+   return pressureSensor;   
+}
+
+int main ()
+{
+   upm::IPressureSensor* pressureSensor = getPressureSensor();
+   if (pressureSensor == NULL) {
+      std::cout << "Pressure sensor not detected" << std::endl;                        
+      return 1;
+   }
+   std::cout << "Pressure sensor " << pressureSensor->getModuleName() << " detected" << std::endl;
+   while (true) {
+      try {
+         int value = pressureSensor->getPressurePa();
+         std::cout << "Pressure = " << value << " Pa" << std::endl;
+      } catch (std::exception& e) {
+         std::cerr << e.what() << std::endl;
+      }
+      sleep(1);         
+   }
+   delete pressureSensor;
+   return 0;
+}
+
+//! [Interesting]