https://devzone.nordicsemi.com/f/nordic-q-a/119226/esb-ack-not-receivedHi, I&#39;m using the nRF52840 DK with SDK 17.0.2. I&#39;ve set selective_auto_ack to true , which should allow the use of dynamic ACK (or ACK payload). I have two types of data packets, one requires an ack, the other does not. Both are received in RX. en-USTelligent Community 13Mon, 05 May 2025 03:26:45 GMThttps://devzone.nordicsemi.com/thread/533837?ContentTypeID=1Mon, 05 May 2025 03:26:45 GMT137ad170-7792-4731-bb38-c0d22fbe4515:38a2c46f-6ea3-483f-b19d-ad472096a52cHsin<p>Thank you.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/524512?ContentTypeID=1Tue, 25 Feb 2025 08:48:42 GMT137ad170-7792-4731-bb38-c0d22fbe4515:91a2bad6-8000-43a5-b6f5-8b117c5247adKenneth<p>I suggest to go back a bit to the default example and compare, you are likely missing something. E.g. make sure PRX is in RX mode, make sure you only have one PRX in the area.</p> <p>Kenneth</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/524471?ContentTypeID=1Tue, 25 Feb 2025 03:38:35 GMT137ad170-7792-4731-bb38-c0d22fbe4515:fe653e46-2ab3-4164-a91a-f8b041a160d1Hsin<p>I set <span>selective_auto_ack&nbsp;</span>to true on both the PRX and PTX.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/524432?ContentTypeID=1Mon, 24 Feb 2025 19:44:40 GMT137ad170-7792-4731-bb38-c0d22fbe4515:66d041ff-a8fe-4fd3-9c86-3c9b6976f535Kenneth<p>Hello,</p> <p>What have you set&nbsp;selective_auto_ack to on the PRX and PTX? It needs to be the same on both PTX and PRX.</p> <p>From the description of the field:<br />&quot;Enable or disable selective auto acknowledgement. When this feature is disabled, all packets will be acknowledged ignoring the noack field.&quot;</p> <p>Kenneth</p><div style="clear:both;"></div>