https://devzone.nordicsemi.com/f/nordic-q-a/34263/migrate-from-nrf51822-s110-sdk8-0-0-to-nrf52840-s140-sdk15-0-0-in-iarHi, I have project for NRF51822 in IAR(EWARM). Short about project: it based on example BLE to UART communication; it uses SPI, I2C, analog inputs readings, some digital outputs; it uses SoftDevice S110 and sdk 8.0.0. Recently I got NRF52840 Previewen-USTelligent Community 13Fri, 11 May 2018 13:28:35 GMThttps://devzone.nordicsemi.com/thread/131716?ContentTypeID=1Fri, 11 May 2018 13:28:35 GMT137ad170-7792-4731-bb38-c0d22fbe4515:20740a0f-2083-4467-b6d3-65e44e2ab186Einar Thorsrud<p>Hi,</p> <p>We do not have a migration guide that describes migrating from nRF51 to nRF52840, nor any guide to migrate from SDK 8 to SDK 15. There are simply too many changes.</p> <p>There are so many changes between nRF51 with SDK 8 and S110 and nRF52840 with SDK 15 and S140 that I attempting to migrate the project&nbsp;is a bad idea. Restarting a new project will likely be far less work. Then you can start off with SDK example that is similar to your product and adjust and add features from your nRF51 project gradually while making sure that things work and sorting out API differences along the way.</p><div style="clear:both;"></div>