Producer-consumer pattern in FreeRTOS - Mini Project: Build & Apply

Producer-Consumer Pattern with FreeRTOS

📖 Scenario: You are building a simple embedded system using FreeRTOS where one task produces data and another task consumes it. This pattern helps manage data flow safely between tasks.

🎯 Goal: Create two FreeRTOS tasks: a producer task that sends numbers to a queue, and a consumer task that receives and prints those numbers.

📋 What You'll Learn

Create a FreeRTOS queue to hold integers

Create a producer task that sends numbers 1 to 5 to the queue

Create a consumer task that receives numbers from the queue

Print each received number in the consumer task

💡 Why This Matters

🌍 Real World

Producer-consumer patterns are common in embedded systems to manage data flow between sensors and processing tasks without data loss.

💼 Career

Understanding FreeRTOS task communication is essential for embedded software engineers working on real-time applications.

1

Create a FreeRTOS queue

Create a FreeRTOS queue called queue that can hold 5 integers using xQueueCreate(5, sizeof(int)).

FreeRTOS

#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"

QueueHandle_t queue;

int main(void) {
    // Create the queue here
    // Your code here
    return 0;
}

Need a hint?

Use xQueueCreate with 5 as the number of items and sizeof(int) as the size of each item.

2

Create the producer task

Create a FreeRTOS task called producer using xTaskCreate. The producer task should send numbers 1 to 5 to the queue using xQueueSend inside a loop.

FreeRTOS

#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"

QueueHandle_t queue;

void producer(void *params) {
    for (int i = 1; i <= 5; i++) {
        xQueueSend(queue, &i, portMAX_DELAY);
    }
    vTaskDelete(NULL);
}

int main(void) {
    queue = xQueueCreate(5, sizeof(int));
    // Create the producer task here
    // Your code here
    return 0;
}

Need a hint?

Use xTaskCreate with the producer function, a name, stack size 1000, no parameters, priority 1, and no task handle.

3

Create the consumer task

Create a FreeRTOS task called consumer using xTaskCreate. The consumer task should receive numbers from the queue using xQueueReceive inside a loop and print each number using printf.

FreeRTOS

#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
#include 

QueueHandle_t queue;

void producer(void *params) {
    for (int i = 1; i <= 5; i++) {
        xQueueSend(queue, &i, portMAX_DELAY);
    }
    vTaskDelete(NULL);
}

void consumer(void *params) {
    int value;
    for (int i = 0; i < 5; i++) {
        xQueueReceive(queue, &value, portMAX_DELAY);
        printf("Received: %d\n", value);
    }
    vTaskDelete(NULL);
}

int main(void) {
    queue = xQueueCreate(5, sizeof(int));
    xTaskCreate(producer, "Producer", 1000, NULL, 1, NULL);
    // Create the consumer task here
    // Your code here
    return 0;
}

Need a hint?

Use xTaskCreate to create the consumer task and then start the scheduler with vTaskStartScheduler().

4

Run and observe the output

Run the program and observe the printed output from the consumer task. The output should show the numbers 1 to 5 received from the producer task.

FreeRTOS

Need a hint?

Check that the consumer prints all numbers from 1 to 5 in order.