https://devzone.nordicsemi.com/f/nordic-q-a/10699/create-timer-hardfaultHi, I&#39;m porting my project from SDK8.1 to SDK10 and got a problem in app_timer.c Main chip :nRF51822 QFACA1 Crystal:32Mhz, no 32.768 Initial is fine. APP_TIMER_INIT(APP_TIMER_PRESCALER, APP_TIMER_OP_QUEUE_SIZE, NULL); APP_TIMER_PRESCALERen-USTelligent Community 13Tue, 08 Dec 2015 01:58:33 GMThttps://devzone.nordicsemi.com/thread/39938?ContentTypeID=1Tue, 08 Dec 2015 01:58:33 GMT137ad170-7792-4731-bb38-c0d22fbe4515:940e9260-743b-4aa8-9aff-ed15cb59a59bfrogofmagic<p>Thank you :) I will try it ~</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/39937?ContentTypeID=1Mon, 07 Dec 2015 16:16:32 GMT137ad170-7792-4731-bb38-c0d22fbe4515:43158b4e-2379-4434-ad57-57c21c57398dKrzysztof Chruscinski<p>Hi,</p> <p>you need to replace</p> <pre><code>app_timer_id_t a4wp_sm_ptu_start_timer_id; </code></pre> <p>with</p> <pre><code>APP_TIMER_DEF(a4wp_sm_ptu_start_timer_id); </code></pre> <p>Macro additionally allocates memory for timer instance. For details check out app_timer documentation: <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk51.v10.0.0/lib_timer.html?cp=4_1_0_3_25">http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk51.v10.0.0/lib_timer.html?cp=4_1_0_3_25</a></p><div style="clear:both;"></div>