https://devzone.nordicsemi.com/f/nordic-q-a/65337/rtc0-in-ble-activityDear all, I&#39;m developing my thesis project and I&#39;m using 2 custom nrf52840-DK. I manage to implement BLE and the 2 boards actually connect and communicate beetween them. I&#39;m using sdk 17.00 and s140 softdevice. I read the s140 documentation and I knowen-USTelligent Community 13Fri, 28 Aug 2020 08:48:00 GMThttps://devzone.nordicsemi.com/thread/266908?ContentTypeID=1Fri, 28 Aug 2020 08:48:00 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d59a3b36-c1e4-455e-9a75-a7c0e6b0513dElia_pell<p>So, if I would like to sync my trasmission of data with connection interval, will I have to set up another rtc (rtc1/rtc2) at the start of the connection and set up a compare channel equal to my connection interval?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/266906?ContentTypeID=1Fri, 28 Aug 2020 08:44:50 GMT137ad170-7792-4731-bb38-c0d22fbe4515:841eec09-7de3-485d-9539-1a89b7d880d8Turbo J[quote userid="92986" url="~/f/nordic-q-a/65337/rtc0-in-ble-activity"]which of them is used to scheduled the connection interval[/quote] <p>The connection interval timing is done via RTC.</p> <p>This allows the high frequency clock (HFINT/HFCLK) to be turned off completely in between radio events - unless it is in use by other peripherials or the MCU core.</p><div style="clear:both;"></div>