flight/modules/Example/examplemodperiodic.c

   1 /**
   2  ******************************************************************************
   3  *
   4  * @file       examplemodperiodic.c
   5  * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
   6  * @brief      Example module to be used as a template for actual modules.
   7  *             Threaded periodic version.
   8  *
   9  * @see        The GNU Public License (GPL) Version 3
  10  *
  11  *****************************************************************************/
  12 /*
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 3 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful, but
  19  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  20  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  21  * for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License along
  24  * with this program; if not, write to the Free Software Foundation, Inc.,
  25  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  26  */
  27
  28 /**
  29  * Input object: ExampleSettings
  30  * Output object: ExampleObject2
  31  *
  32  * This module will periodically update the value of the ExampleObject object.
  33  * The module settings can configure how the ExampleObject is manipulated.
  34  *
  35  * The module executes in its own thread in this example.
  36  *
  37  * UAVObjects are automatically generated by the UAVObjectGenerator from
  38  * the object definition XML file.
  39  *
  40  * Modules have no API, all communication to other modules is done through UAVObjects.
  41  * However modules may use the API exposed by shared libraries.
  42  * See the OpenPilot wiki for more details.
  43  * http://www.openpilot.org/OpenPilot_Application_Architecture
  44  *
  45  */
  46
  47 #include "openpilot.h"
  48 #include "examplemodperiodic.h"
  49 #include "exampleobject2.h" // object that will be updated by the module
  50 #include "examplesettings.h" // object holding module settings
  51
  52 // Private constants
  53 #define STACK_SIZE    configMINIMAL_STACK_SIZE
  54 #define TASK_PRIORITY (tskIDLE_PRIORITY + 1)
  55
  56 // Private types
  57
  58 // Private variables
  59 static xTaskHandle taskHandle;
  60
  61 // Private functions
  62 static void exampleTask(void *parameters);
  63
  64 /**
  65  * Initialise the module, called on startup
  66  * \returns 0 on success or -1 if initialisation failed
  67  */
  68 int32_t ExampleModPeriodicInitialize()
  69 {
  70     // Start main task
  71     xTaskCreate(exampleTask, (signed char *)"ExamplePeriodic", STACK_SIZE, NULL, TASK_PRIORITY, &taskHandle);
  72
  73     return 0;
  74 }
  75
  76 /**
  77  * Module thread, should not return.
  78  */
  79 static void exampleTask(__attribute__((unused)) void *parameters)
  80 {
  81     ExampleSettingsData settings;
  82     ExampleObject2Data data;
  83     int32_t step;
  84     portTickType lastSysTime;
  85
  86     // Main task loop
  87     lastSysTime = xTaskGetTickCount();
  88     while (1) {
  89         // Update settings with latest value
  90         ExampleSettingsGet(&settings);
  91
  92         // Get the object data
  93         ExampleObject2Get(&data);
  94
  95         // Determine how to update the data
  96         if (settings.StepDirection == EXAMPLESETTINGS_STEPDIRECTION_UP) {
  97             step = settings.StepSize;
  98         } else {
  99             step = -settings.StepSize;
 100         }
 101
 102         // Update the data
 103         data.Field1    += step;
 104         data.Field2    += step;
 105         data.Field3    += step;
 106         data.Field4[0] += step;
 107         data.Field4[1] += step;
 108
 109         // Update the ExampleObject, after this function is called
 110         // notifications to any other modules listening to that object
 111         // will be sent and the GCS object will be updated through the
 112         // telemetry link. All operations will take place asynchronously
 113         // and the following call will return immediately.
 114         ExampleObject2Set(&data);
 115
 116         // Since this module executes at fixed time intervals, we need to
 117         // block the task until it is time for the next update.
 118         // The settings field is in ms, to convert to RTOS ticks we need
 119         // to divide by portTICK_RATE_MS.
 120         vTaskDelayUntil(&lastSysTime, settings.UpdatePeriod / portTICK_RATE_MS);
 121     }
 122 }