docs/en/api/timer.rst
Timer
The ESP32 SoCs contains from 2 to 4 hardware timers. They are all 64-bit (54-bit for ESP32-C3) generic timers based on 16-bit pre-scalers and 64-bit (54-bit for ESP32-C3) up / down counters which are capable of being auto-reloaded.
========= ================ ESP32 SoC Number of timers ========= ================ ESP32 4 ESP32-S2 4 ESP32-S3 4 ESP32-C3 2 ESP32-C6 2 ESP32-H2 2 ========= ================
timerBegin
This function is used to configure the timer. After successful setup the timer will automatically start.
.. code-block:: arduino
hw_timer_t * timerBegin(uint32_t frequency);
frequency select timer frequency in Hz. Sets how quickly the timer counter is “ticking”.This function will return timer structure if configuration is successful.
If NULL is returned, error occurs and the timer was not configured.
timerEnd
This function is used to end timer.
.. code-block:: arduino
void timerEnd(hw_timer_t * timer);
timer timer struct.timerStart
This function is used to start counter of the timer.
.. code-block:: arduino
void timerStart(hw_timer_t * timer);
timer timer struct.timerStop
This function is used to stop counter of the timer.
.. code-block:: arduino
void timerStop(hw_timer_t * timer);
timer timer struct.timerRestart
This function is used to restart counter of the timer.
.. code-block:: arduino
void timerRestart(hw_timer_t * timer);
timer timer struct.timerWrite
This function is used to set counter value of the timer.
.. code-block:: arduino
void timerWrite(hw_timer_t * timer, uint64_t val);
timer timer struct.val counter value to be set.timerRead
This function is used to read counter value of the timer.
.. code-block:: arduino
uint64_t timerRead(hw_timer_t * timer);
timer timer struct.This function will return counter value of the timer.
timerReadMicros
This function is used to read counter value in microseconds of the timer.
.. code-block:: arduino
uint64_t timerReadMicros(hw_timer_t * timer);
timer timer struct.This function will return counter value of the timer in microseconds.
timerReadMillis
This function is used to read counter value in milliseconds of the timer.
.. code-block:: arduino
uint64_t timerReadMillis(hw_timer_t * timer);
timer timer struct.This function will return counter value of the timer in milliseconds.
timerReadSeconds
This function is used to read counter value in seconds of the timer.
.. code-block:: arduino
double timerReadSeconds(hw_timer_t * timer);
timer timer struct.This function will return counter value of the timer in seconds.
timerGetFrequency
This function is used to get resolution in Hz of the timer.
.. code-block:: arduino
uint16_t timerGetFrequency(hw_timer_t * timer);
timer timer struct.This function will return frequency in Hz of the timer.
timerAttachInterrupt
This function is used to attach interrupt to timer.
.. code-block:: arduino
void timerAttachInterrupt(hw_timer_t * timer, void (*userFunc)(void));
timer timer struct.userFunc function to be called when interrupt is triggered.timerAttachInterruptArg
This function is used to attach interrupt to timer using arguments.
.. code-block:: arduino
void timerAttachInterruptArg(hw_timer_t * timer, void (*userFunc)(void*), void * arg);
timer timer struct.userFunc function to be called when interrupt is triggered.arg pointer to the interrupt arguments.timerDetachInterrupt
This function is used to detach interrupt from timer.
.. code-block:: arduino
void timerDetachInterrupt(hw_timer_t * timer);
timer timer struct.timerAlarm
This function is used to configure alarm value and autoreload of the timer. Alarm is automatically enabled.
.. code-block:: arduino
void timerAlarm(hw_timer_t * timer, uint64_t alarm_value, bool autoreload, uint64_t reload_count);
timer timer struct.alarm_value alarm value to generate event.autoreload enabled/disabled autorealod.reload_count number of autoreloads (0 = unlimited). Has no effect if autorealod is disabled.Example Applications
There are 2 examples uses of Timer:
Repeat timer example:
.. literalinclude:: ../../../libraries/ESP32/examples/Timer/RepeatTimer/RepeatTimer.ino :language: arduino
Watchdog timer example:
.. literalinclude:: ../../../libraries/ESP32/examples/Timer/WatchdogTimer/WatchdogTimer.ino :language: arduino