Merge pull request #71 from hectorespert/mutex

Add Mutex example

Author: feilipu

.gitignore

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+# Ignore .development file, https://arduino.github.io/arduino-cli/library-specification/#development-flag-file
+.development

examples/Mutex/Mutex.ino

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+/*
+   Example of a FreeRTOS mutex
+   https://www.freertos.org/Real-time-embedded-RTOS-mutexes.html
+*/
+
+// Include Arduino FreeRTOS library
+#include <Arduino_FreeRTOS.h>
+
+
+// Include mutex support
+#include <semphr.h>
+
+/*
+   Declaring a global variable of type SemaphoreHandle_t
+
+*/
+SemaphoreHandle_t mutex;
+
+int globalCount = 0;
+
+void setup() {
+
+  Serial.begin(9600);
+
+  /**
+       Create a mutex.
+       https://www.freertos.org/CreateMutex.html
+  */
+  mutex = xSemaphoreCreateMutex();
+  if (mutex != NULL) {
+    Serial.println("Mutex created");
+  }
+
+  /**
+     Create tasks
+  */
+  xTaskCreate(TaskMutex, // Task function
+              "Task1", // Task name for humans
+              128, 
+              1000, // Task parameter
+              1, // Task priority
+              NULL);
+
+  xTaskCreate(TaskMutex, "Task2", 128, 1000, 1, NULL);
+
+}
+
+void loop() {}
+
+void TaskMutex(void *pvParameters)
+{
+  int delay = *((int*)pvParameters); // Use task parameters to define delay
+
+  for (;;)
+  {
+    /**
+       Take mutex
+       https://www.freertos.org/a00122.html
+    */
+    if (xSemaphoreTake(mutex, 10) == pdTRUE)
+    {
+      Serial.print(pcTaskGetName(NULL)); // Get task name
+      Serial.print(", Count readed value: ");
+      Serial.print(globalCount);
+
+      globalCount++;
+
+      Serial.print(", Updated value: ");
+      Serial.print(globalCount);
+
+      Serial.println();
+      /**
+         Give mutex
+         https://www.freertos.org/a00123.html
+      */
+      xSemaphoreGive(mutex);
+    }
+
+    vTaskDelay(delay / portTICK_PERIOD_MS);
+  }
+}