I have an issue when i am using an iPhone 8 instead of iPhone 7 , I can use iphone7 to OTA my BLE UART by NRF tool box, but ,when i useing iphone 8 , it does not work, what could be the root cause ?

[Michael.lee]

I have an issue when i am using an iPhone 8 instead of iPhone 7 , I can use iphone7 to OTA my BLE UART  by NRF tool box, but ,when i useing iphone 8 , it does not work, what could be the root cause ?

[Hung Bui]

Hi Michael, 

Could you give some more information about the bootloader ? Which SDK and softdevice ? 

Which error code do you see ? on both side, the phone and the nRF52. 
Please try to capture a sniffer trace when you do DFU on iPhone 7 and the same procedure on iPhone 8 so we can compare. 

[Michael.lee]

HI Huang Bui

Thank you for your prompt reply! under here you can check my infomation:

1. s332_nrf52_5.0.0_softdevice.hex

2.NRF52832_xxaa

3.SDK: nRF5_SDK_14.2.0_17b948a

if fact, I do not have a Sniffer tools on hand yet, but ,I will try to get one later,

Before that ,have you heard this same thing before ? And how did they solve it ?

[Hung Bui]

I suspect that iPhone 8 may request a feature that the S332 doesn't support or support but require proper application implementation. If it is not handled properly in the bootloader code it may result in an error. For example DLE or long ATT_MTU. 
A sniffer trace would reveal that. Please also find the error log on the nRF Connect app on the phone. 

[Michael.lee]

OK, I will try to find a Sniffer tools , but in case Iphone 8 need long ATT_MTU , that means, it does not compatible to down side . right ?

[Hung Bui]

Hi Michael, 
If it's the case it should be possible to handle/reject the request from the application. We just need to check what exactly happens when the iPhone8 connects.