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Code: Select all

#include <freertos/FreeRTOS.h>
#include <freertos/task.h>
#include <atomic>
#include <WebServer.h>

std::atomic<bool> taskRun(true);
TaskHandle_t taskHandle = NULL;

WebServer webServer(80);

void setup() {
  Serial.begin(115200);
  delay(2000);
  Serial.println("==== START ====");

  WiFi.mode(WIFI_STA);
  WiFi.begin("ssid", "password");
  while(WiFi.status() != WL_CONNECTED);
  Serial.println(WiFi.localIP().toString());

  webServer.on("/reset", []() {
    webServer.send(200, "text/html", "ok");
    resetTask();
  });
  webServer.begin();
}

void loop() {
  // Watch the task and start it if necessary
  if (!taskHandle || eTaskGetState(taskHandle) == eDeleted) { // sometimes the task finished but is still in eReady state, so it does not restart
    Serial.println(millis());
    taskRun.store(true);
    xTaskCreatePinnedToCore(taskFunction, "task", 10000, NULL, 1, &taskHandle, 1);
    Serial.println("task created");
  }

  webServer.handleClient(); // allow the user to stop and restart the task through the web server

  if (Serial.available()){  // allow the user to stop and restart the task through the serial monitor
    Serial.read();
    //delay(500);
    resetTask();
    //delay(500);
  }
}

void resetTask() {
  taskRun.store(false);
  Serial.println("reset task");
}

void taskFunction(void* pvParameters) {
  while(taskRun.load()) {
    // do work
    taskYIELD(); // give cpu time to other tasks
  }
  
  Serial.println("task finished");
  vTaskDelete(NULL);
}

Code: Select all

void taskFunction(void*) {
  {
  ...
  }
  
  Serial.println("task finished");
  
  // Announce that we're done:
  xSemaphoreGive( taskEndedSem );
  // Go dormant until deleted from elsewhere
  while(1) {
    vTaskSuspend(NULL);
  }
  
}

void resetTask() {
  if(taskHandle) {
    taskRun.store(false); // Tell the task to terminate
  
    // Wait until the task is ready to be deleted:
    xSemaphoreTake( taskEndedSem, portMAX_DELAY );  
  
    // Delete task (taskHandle still valid):
    vTaskDelete( taskHandle );
  
    // Task is deleted, taskHandle is now invalid
    taskHandle = NULL;
    taskRun.store(true);
  
    Serial.println("reset task");
  }
}

void loop() {
  ...
  if(...) {
    resetTask();
  
    // Recreate task:
    xTaskCreatePinnedToCore(taskFunction, "task", 10000, NULL, 1, &taskHandle, 1);
    Serial.println("task created");
  }
  ...
}