使用串口保存日志，格式是十六进制的

串口记录的log，文件里是这样的
[2026-06-10 16:57:07] Received 64 bytes.
0000: 49 20 28 38 35 39 33 30 29 20 42 4c 45 2d 54 41 I (85930) BLE-TA
0010: 47 3a 20 5b 67 61 74 74 63 5f 70 72 6f 66 69 6c G: [gattc_profil
0020: 65 5f 65 76 65 6e 74 5f 68 61 6e 64 6c 65 72 3a e_event_handler:
0030: 31 34 39 34 5d 20 43 68 61 72 61 63 74 65 72 69 1494] Characteri
[2026-06-10 16:57:07] Received 27 bytes.
0000: 73 74 69 63 20 77 72 69 74 65 20 73 75 63 63 65 stic write succe
0010: 73 73 66 75 6c 6c 79 0d 0a 0d 0a ssfully....
实际串口的打印是正常的打印

I (199930) BLE-TAG: [gattc_profile_event_handler:1494] Characteristic write successfully

I (202930) BLE-TAG: [gattc_profile_event_handler:1494] Characteristic write successfully
而且每次串口去连接的时候都会卡好一会

The report does not name files, tests, or entry points. Start by reproducing the serial connection and compare the displayed output with the saved log, then trace the serial logging and connection-handling code. Done means saved logs retain readable output instead of hexadecimal bytes and connecting no longer pauses unexpectedly.

Written by the indexing model from the issue text.