Health monitoring and heartbeat in FreeRTOS

Introduction

Health monitoring and heartbeat help check if a system or task is working well. It tells us early if something stops or slows down.

To know if a FreeRTOS task is still running without problems.

To detect if a device or sensor is alive and sending data.

To restart a system part automatically if it stops responding.

To monitor system health in real-time during operation.

To send alerts when a system component fails or hangs.

Syntax

FreeRTOS

void vTaskHeartbeat(void *pvParameters) {
    for (;;) {
        // Send heartbeat signal or update status
        vTaskDelay(pdMS_TO_TICKS(heartbeat_interval_ms));
    }
}

The heartbeat function usually runs in a FreeRTOS task that loops forever.

Use vTaskDelay() to wait between heartbeats without blocking other tasks.

Examples

This example prints a heartbeat message every 1 second.

FreeRTOS

void vTaskHeartbeat(void *pvParameters) {
    for (;;) {
        printf("Heartbeat sent\n");
        vTaskDelay(pdMS_TO_TICKS(1000));
    }
}

This example toggles an LED every 0.5 seconds as a heartbeat signal.

FreeRTOS

void vTaskHeartbeat(void *pvParameters) {
    for (;;) {
        // Toggle an LED to show system is alive
        ToggleLED();
        vTaskDelay(pdMS_TO_TICKS(500));
    }
}

Sample Program

This program creates a FreeRTOS task that prints a heartbeat message every 2 seconds. The scheduler runs the task repeatedly.

FreeRTOS

#include "FreeRTOS.h"
#include "task.h"
#include <stdio.h>

void vTaskHeartbeat(void *pvParameters) {
    for (;;) {
        printf("Heartbeat: system is alive\n");
        vTaskDelay(pdMS_TO_TICKS(2000));
    }
}

int main(void) {
    xTaskCreate(vTaskHeartbeat, "HeartbeatTask", configMINIMAL_STACK_SIZE, NULL, 1, NULL);
    vTaskStartScheduler();
    return 0;
}

Important Notes

Heartbeat intervals should be chosen carefully to balance responsiveness and CPU load.

Use watchdog timers with heartbeat to reset system if heartbeat stops.

Heartbeat can be a simple message, LED toggle, or signal to another system part.

Summary

Heartbeat tasks run repeatedly to show system health.

Use vTaskDelay() to wait between heartbeats without blocking.

Heartbeat helps detect failures early and keep systems reliable.