DSPS.device - UART boot looks OK but no detection

Hello Support Team,

I am working with a board that has the PAN1740 module (DA14580-01 based) and an external microcontroller.
I am trying to just run the DSPS device demo as is , with DA14580 booting from UART on P0_4 and P0_5 and getting the code from the external micro.
I am able to succesfully run the full boot sequence (as specified in AN-B-001), with the DA14580 finally returning the correct CRC (XOR over full code) and my micro providing the final acknowledge (0x06). However after that, when I run the iOS DSPS application on an iPad Mini, nothing gets detected.

In more details, here's what I have done :

1）在Keil UVision5（具有“遗留”包装）：
open project .../keil_projects/sps/sps_device/sps_device.uvproj
This is from package DA14580_DSPS_3.150.2.
(Note the DSPS User Manual UM-B-038 rev.1.2, in section 8.5/8.3, refers to a different path and filename:
"...\dk_apps\keil_projects\sps\sps_device_fh\sps_device_fh.uvproj",
但是在DSP包中不存在我使用的DSP包中 - 我相信是最新的。
Also, in that package, in addition to sps_device.uvproj, there is also an alternative sps_device_581.uvproj, but I assume this is not for DA14580.)

2) In Keil uVision menu "Project-->Options for Target":
- under tab "Device": select DA14580
- under tab "User": enable option: "after build/rebuild, run: ...\KEIL-v5\ARM\ARMCC\bin\fromelf.exe --bincombined out\sps_device.axf --output binout\sps_device.bin". This invokes Keil's hex2bin converter to produce a single .bin file.
——构建/重建所有目标文件。
Result:
Program Size: Code=14248 RO-data=1204 RW-data=64 ZI-data=10348
FromELF: creating hex file...
构建之后 - 用户命令＃1：“C：\ Program Files（x86）\ keil-v5 \ arm \ armcc \ bin \ fromelf.exe”--bincombined out \ sps_device.axf --output binout \ sps_device.bin
“。\ out \ sps_device.axf” - 0错误，3个警告。

In addition to the .hex file (size 42.7KB) (which I won't use), I get a .bin file (size 15.4KB) as expected.
[ Notes:
- If I use option --bin rather than --bincombined I get 5 files ER_IROM1 to ER_IROM5; I have checked that my single .bin file contains these 5 sections with 0xFF padding in between.
- If I run the hex2bin file found under ...\DIALOG SDK\DA1458x_SDK_3.0.6\DA1458x_SDK_3.0.6\tools\flash_programmer, I get the same resulting .bin ]

3) Because my board can also be seen from any PC as a USB drive, I just copy this .bin file into some memory on my board.

4) Then my microcontroller resets the DA14580 and starts the boot interaction.
When the DA14580 expects the code bytes, the micro just reads the .bin file and provides the code from the first byte (which I expect will go to address 0x20000000 in the DA14580 i.e. first byte of SysRAM) to the last byte found in the file.
As I wrote, this looks to work fine: DA14580 then provides expected CRC and my micro provides the final acknowledge (0x06).

我相信此时，DA14580应该发出内部软复位，并且应该执行应用程序，从而可检测到。
But the iOS App does not detect any peripheral device.

Any suggestion ???

Thanks -