https://devzone.nordicsemi.com/f/nordic-q-a/54076/i-want-to-send-heart-rate-data-to-smartphone-using-nrf51422-in-every-secondHI, I want to send heart rate data to smartphone using NRF51422 in every second without any time delay or minimal time delay ranges between(0.9 to 1.1 sec). Thanks for reading. Regards, MAHIen-USTelligent Community 13Thu, 07 Nov 2019 09:37:01 GMThttps://devzone.nordicsemi.com/thread/218996?ContentTypeID=1Thu, 07 Nov 2019 09:37:01 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b1d065f4-092c-4ae4-9fb6-703c25431168ovrebekk<p>Hi</p> <p>Which SDK version are you using?</p> <p>There is a library called <a href="https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v12.3.0/lib_timer.html?cp=5_5_8_3_33">app_timer</a> in the SDK which allows you to register a callback every second, and from there you can&nbsp;send an update over the BLE link.&nbsp;</p> <p>The delay over a BLE link is set primarily by the connection interval, where a lower connection interval reduces the latency between the two devices.</p> <p>Best regards<br />Torbjørn</p><div style="clear:both;"></div>