Method setCallback

Sming/Core/CallbackTimer.h:391–397

@brief Set timer trigger callback * @param callback Function to call when timer triggers * @param arg Optional argument passed to callback */

     *  @param  arg Optional argument passed to callback
     */
	__forceinline void IRAM_ATTR setCallback(TimerCallback callback, void* arg = nullptr)
	{
		// Always disarm before setting the callback
		stop();
		TimerApi::setCallback(callback, arg);
		callbackSet = (callback != nullptr);
	}

	/**
	 * @brief Set timer trigger callback