https://devzone.nordicsemi.com/f/nordic-q-a/83551/bluetooth-stack-initialization-failed1. When I run the SDK routine provided by the official, ble_app_uart program, the circuit board acts as the peripheral , the protocol stack is pre-downloaded to the board, the program runs normally, the RAM and ROM configuration is as shown below: en-USTelligent Community 13Tue, 11 Jan 2022 15:20:42 GMThttps://devzone.nordicsemi.com/thread/347222?ContentTypeID=1Tue, 11 Jan 2022 15:20:42 GMT137ad170-7792-4731-bb38-c0d22fbe4515:80b4322b-2f59-4f12-b184-bec0ffb3b2dfEinar Thorsrud<p>Hi,</p> <p>When you initialize the SoftDevice it will check if the RAM configuration matches the configuration. If you have not set aside enough RAM, you will get an error. The RAM usage of the SoftDevice is configuration dependent, so this will typically vary from application to application. See <a href="https://devzone.nordicsemi.com/guides/short-range-guides/b/getting-started/posts/adjustment-of-ram-and-flash-memory">Adjustment of RAM and Flash memory</a>.</p><div style="clear:both;"></div>