ESP32 Timer Auto-Reload Not Working

In this tutorial, you'll learn about ESP32 Timer Auto. We cover key concepts, practical examples, and best practices.

The Problem

ESP32 timer fires once but does not reload and fire repeatedly.

Quick Fix

Wrong

timer_config_t config = {
  .auto_reload = TIMER_AUTORELOAD_DIS,  // Wrong!

Timer fires once then stops. No further alarms.

Right

timer_config_t config = {
  .alarm_en = TIMER_ALARM_EN,
  .counter_en = TIMER_PAUSE,
  .intr_type = TIMER_INTR_LEVEL,
  .counter_dir = TIMER_COUNT_UP,
  .auto_reload = TIMER_AUTORELOAD_EN,
  .divider = 8000
};
timer_init(TIMER_GROUP_0, TIMER_0, &config);
timer_set_alarm_value(TIMER_GROUP_0, TIMER_0, 10000);
timer_set_counter_value(TIMER_GROUP_0, TIMER_0, 0);
timer_enable_intr(TIMER_GROUP_0, TIMER_0);
timer_start(TIMER_GROUP_0, TIMER_0);

Timer fires every 1 second continuously until stopped.

Prevention

Set auto_reload = TIMER_AUTORELOAD_EN. Reset counter value with timer_set_counter_value(). Alarm value sets the reload target. Use auto_reload for PWM-like timing. Disable for one-shot timers.

DodaTech engineers apply these same patterns across Doda Browser, DodaZIP, and Durga Antivirus Pro for production IoT reliability.

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