https://devzone.nordicsemi.com/f/nordic-q-a/36423/uart-example-apisHello- I am working with the nRF52840 with the 14.1 SDK. I am using the 15.4 UART example and currently only data_ack is enabled. I am hoping to add poll_data and poll_ack, what API&#39;s would you suggest to implement these features? Thanks in advanceen-USTelligent Community 13Tue, 17 Jul 2018 14:35:06 GMThttps://devzone.nordicsemi.com/thread/140413?ContentTypeID=1Tue, 17 Jul 2018 14:35:06 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f31f9553-09a3-4ab8-871b-e046b4b428b1Simon<p>What example specifically are you thinking of? UART emulated over BLE or normal UART? Since acknowlegment doesn&#39;t make sense regarding normal UART, I guess it is the former&nbsp;(either&nbsp;<a href="http://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.thread_zigbee.v1.0.0%2Fthread_multi_switched_uart_coap_example.html">this</a>&nbsp;or&nbsp;<a href="https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v14.0.0%2Findex.html">this</a>&nbsp;example maybe).</p> <p>However if you want to access the link layer (where acknowledgement takes places), this is not possible due to restricted accessibility:&nbsp;<a href="https://devzone.nordicsemi.com/f/nordic-q-a/18094/apis-for-link-layer-control-procedures">https://devzone.nordicsemi.com/f/nordic-q-a/18094/apis-for-link-layer-control-procedures</a>.</p> <p>Here are the API for respectively for the UART (hardware) and the Nordic UART service (emulation of UART over BLE):&nbsp;</p> <p><a href="https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v12.0.0%2Fgroup__nrf__uart__hal.html">https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v12.0.0%2Fgroup__nrf__uart__hal.html</a></p> <p><a href="https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v14.0.0%2Fble_sdk_app_nus_eval.html">https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v14.0.0%2Fble_sdk_app_nus_eval.html</a></p> <p>Best regards Simon Iversen</p><div style="clear:both;"></div>