https://devzone.nordicsemi.com/f/nordic-q-a/22825/what-is-3ul-compare-time-in-rtcIn example of peripheral RTC, It compares time of 3UL. BUT I&#39;ve never heard about any measurement of UL... How can i transform it to second???en-USTelligent Community 13Thu, 15 Jun 2017 13:03:15 GMThttps://devzone.nordicsemi.com/thread/89732?ContentTypeID=1Thu, 15 Jun 2017 13:03:15 GMT137ad170-7792-4731-bb38-c0d22fbe4515:538eefd1-219c-44b3-88e7-2bf75b1cdeecJ&#248;rgen Holmefjord<p>Hi Daniel,</p> <p>The ending UL is a way to specify that a constant in C is of type Unsigned Long. The conversion to seconds will depend on the RTC settings. In the RTC example in the SDK, the prescaler is set to 4095. The <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/rtc.html?cp=2_2_0_24_1#concept_iwc_1mj_sr">frequency of the RTC</a> is given by the function:</p> <pre><code>f_RTC [kHz] = 32.768 / (PRESCALER + 1 ) </code></pre> <p>This gives a frequency of 8 Hz with a prescaler of 4095. If you look in the RTC example, the interrupt trigger is set (using the function <code>nrf_drv_rtc_cc_set()</code>) on the compare event given by <code>COMPARE_COUNTERTIME * 8</code>. This indicated that <code>COMPARE_COUNTERTIME</code> is actually given in seconds, so you can simply change 3 into whatever amount of seconds you want to use.</p> <p>Best regars,</p> <p>Jørgen</p><div style="clear:both;"></div>