Producertask ex2

We will create a task that will pull the temperature value then send it to the BUS.

First we will create a task using the dune_create_task script. Execute the following command

DH> python programs/scripts/dune-create-task.py . DuneAuthor Tutorials/TempProd

This will create TempProd task. Open the DH>src/Tutorials/TempProd/Task.cpp and write the following code.

#include <DUNE/DUNE.hpp>

namespace Tutorials
{
  //! Simple task that produces random temperature measurements.
  namespace TempProd
  {
    using DUNE_NAMESPACES;

    //!Task arguments.
    struct Arguments
    {
      //! PRNG type.
      std::string prng_type;
      //! PRNG seed.
      int prng_seed;
      //! Mean temperature value.
      float mean_value;
      //! Standard deviation of temperature measurements.
      double std_dev;
    };
    
    struct Task: public DUNE::Tasks::Periodic
    {
      //! PRNG handle
      Random::Generator* m_prng;
      //! Task arguments.
      Arguments m_args;

      Task(const std::string& name, Tasks::Context& ctx):
        DUNE::Tasks::Periodic(name, ctx),
        m_prng(NULL)
      {
        param("Standard deviation", m_args.std_dev)
        .description("Standard deviation of produced temperature")
        .units(Units::DegreeCelsius)
        .defaultValue("0.1");

        param("PRNG Type", m_args.prng_type)
        .defaultValue(Random::Factory::c_default);

        param("PRNG Seed", m_args.prng_seed)
        .defaultValue("-1");

        param("Mean value", m_args.mean_value)
        .description("Mean value of produced temperature")
        .units(Units::DegreeCelsius)
        .defaultValue("25.0");
      }

      void
      onEntityReservation(void)
      {
        inf("Starting: %s", resolveEntity(getEntityId()).c_str());
      }

      //! Aquire resources.
      void
      onResourceAcquisition(void)
      {
        m_prng = Random::Factory::create(m_args.prng_type,
                                         m_args.prng_seed);
      }

      //! Release resources.
      void
      onResourceRelease(void)
      {
        Memory::clear(m_prng);
      }


      //! Periodic work.
      void
      task(void)
      {
        IMC::Temperature temperature;
        temperature.value = m_args.mean_value + m_prng->gaussian()*m_args.std_dev;
        temperature.setSourceEntity(getEntityId());
        dispatch(temperature);
      }
    };
  }
}

DUNE_TASK

[Example2 main page] (https://github.com/LSTS/dune/wiki/Example2)
[Next Section: Consumer Task] (https://github.com/LSTS/dune/wiki/ConsumerTask-ex2)