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-lightcontroller.cxx

@@ -0,0 +1,98 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <iostream>
+#include <string>
+#include "lp8860.hpp"
+#include "ds1808lc.hpp"
+#include "hlg150h.hpp"
+
+#define EDISON_I2C_BUS 1   // Edison I2C-1
+#define GPIO_SI7005_CS 20 // Edison GP12
+#define HLG150H_GPIO_RELAY 21
+#define HLG150H_GPIO_PWM 22
+#define LP8860_GPIO_PWR 45 // Edison GP45
+#define DS1808_GPIO_PWR 15 // Edison GP165
+#define DS1808_GPIO_EDISON_LIVE 36 // Edison GP14
+
+//! [Interesting]
+// Simple example of using ILightController to determine 
+// which controller is present and return its name.
+// ILightController is then used to get readings from sensor
+
+upm::ILightController* getLightController()
+{
+   upm::ILightController* lightController = NULL;
+   try {
+      lightController = new upm::LP8860(LP8860_GPIO_PWR, EDISON_I2C_BUS);
+      return lightController;
+   } catch (std::exception& e) {
+      std::cerr << "LP8860: " << e.what() << std::endl;      
+   }
+   try {
+      lightController = new upm::DS1808LC(DS1808_GPIO_PWR, EDISON_I2C_BUS);
+      return lightController;
+   } catch (std::exception& e) {
+      std::cerr << "DS1808LC: " << e.what() << std::endl;      
+   }
+   try {
+      lightController = new upm::HLG150H(HLG150H_GPIO_RELAY, HLG150H_GPIO_PWM);
+      return lightController;
+   } catch (std::exception& e) {
+      std::cerr << "HLG150H: " << e.what() << std::endl;      
+   }
+   return lightController;   
+}
+
+
+void printState(upm::ILightController *lightController)
+{
+   if (lightController->isPowered())
+   {
+      std::cout << "Light is powered, brightness = " << lightController->getBrightness() << std::endl;
+   }
+   else
+   {
+      std::cout << "Light is not powered." << std::endl;
+   }
+}
+
+int main( int argc, char **argv )
+{
+   int status = 0;
+   // MraaUtils::setGpio(GPIO_SI7005_CS, 1);
+
+   upm::ILightController *lightController = getLightController();
+   if (lightController != NULL)
+   {
+      std::cout << "Detected light controller " << lightController->getModuleName() << std::endl;      
+   }
+   else
+   {
+      std::cerr << "Error. Unsupported platform." << std::endl;
+      return 1;
+   }
+
+   try {
+      std::cout <<  "Existing state: "; printState(lightController);      
+      if (argc == 2)
+      {
+         std::string arg = argv[1];
+         int brightness = ::atoi(argv[1]);
+         if (brightness > 0) {
+            lightController->setPowerOn();         
+            lightController->setBrightness(brightness);
+         } else
+            lightController->setPowerOff();                  
+      }
+      std::cout <<  "Now: ";printState(lightController);
+   } catch (std::exception& e) {
+      std::cout << "Error: " << e.what() << std::endl; 
+      status = 1;  
+   }
+
+   delete lightController;
+   return status;
+}
+
+//! [Interesting]