https://devzone.nordicsemi.com/f/nordic-q-a/70537/sdk-backwards-compatibility-support-for-older-sdI was looking at this compatibility matrix, for SD and SDK. https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcomp_matrix_nrf52832%2FCOMP%2Fnrf52832%2Fic_rev_sdk_sd_comp_matrix.html Are SDKs meant to be backwards compatible with all older versionsen-USTelligent Community 13Tue, 19 Jan 2021 09:22:39 GMThttps://devzone.nordicsemi.com/thread/289950?ContentTypeID=1Tue, 19 Jan 2021 09:22:39 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3b66bf03-5411-4f29-b88c-8395999a3549ovrebekk<p>You welcome <span class="emoticon" data-url="https://devzone.nordicsemi.com/cfs-file/__key/system/emoji/1f642.svg" title="Slight smile">&#x1f642;</span></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/289856?ContentTypeID=1Mon, 18 Jan 2021 17:03:19 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ca72afa5-8ef4-4cf4-aefb-dbda48f03ffctlgage<p>Makes sense, thanks!</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/289652?ContentTypeID=1Mon, 18 Jan 2021 09:48:54 GMT137ad170-7792-4731-bb38-c0d22fbe4515:33c47b51-4072-40ac-9384-0e3bb452a824ovrebekk<p>Hi&nbsp;</p> <p>Minor SoftDevice updates (S132 v5.0.0 to v5.1.0 for example) will never change existing API&#39;s, they will only modify the implementation of existing ones or add new ones.&nbsp;</p> <p>This means that you can safely update to a new minor version without changing the SDK.&nbsp;</p> <p>Major SoftDevice updates on the other hand (S132 v5.x.x to v6.x.x for example) can both change and remove existing API functions, in addition to adding new ones, and they will normally not work on other SDK versions than the ones they were designed for.&nbsp;</p> <p></p> <p>This means you normally need to change both the SoftDevice and SDK version if you plan to upgrade to a new major version of the SoftDevice.&nbsp;</p> <p>Best regards<br />Torbjørn</p><div style="clear:both;"></div>