OTA-DFU fail by Android mobile, when device and mobile distance over 80cm..

[JoeYeh]

Dear:
 I had production a device, using:
  nRF51822 + SDK12.3S130 + Bootloader

For update Application packaged code(zip) by OTA-DFU
1. at iOS, we can update code.
2. at Android, Mobile must be close to the device to succeed

Why do Android phones have to be closer to the device(less then 80cm) to complete it, but iOS doesn't?

that distance is too small for user.

Is there any setting that I have overlooked or is there any reference setting in the API program?
Addriod API had insert DFU_Library 1.1.1(Maven Repository: no.nordicsemi.android » dfu » 1.1.1 (mvnrepository.com))

[Hung Bui]

Hi Joe, 
I don't think we have any mechanism that force the DFU master to be in close distance to the DFU target when doing DFU. 
My suspicion is that the link was terminated due to weak RF signal. 

Have you tried to test transmitting some dummy data with the Android device at longer distance ? (for example with ble_app_hrs)

Do you have any log on the bootloader / phone ? 
If you can capture a sniffer trace of the communication between the bootloader and the phone it would be easier to know why the connection is terminated. 

[JoeYeh]

I had using sniffer trace, get CRC Error. 
The CRC Error occurs when data is transmitted in OTA-DFU mode.

and that is using   RedMi 10 & Galaxy A13 with same problem
But Google Pixel 4 XL & galaxy tab s8 can pass the OTA-DFU

I have no idea how to fix it. I can't require all customers to use iphone.

[Hung Bui]

Hi,
What you are showing is an ADV advertising packet. So it may have nothing to do with OTA-DFU. 
Please try to capture a DFU session including a connection. 
We have a sniffer course here that you may want to take a look: https://academy.nordicsemi.com/lessons/lesson-6-bluetooth-le-sniffer/

[JoeYeh]

Hi, Hung:
The OTA-DFU package file with private.key, Can I using Sniffer trace it?
and I had request API whit nRF-Logger-API 
Some messages pop up on the screen, what APP (nRF Logger?) should I install on my phone to get detailed log information?

[ovrebekk]

Hi 

Hung is currently unavailable, and I will help you out until he's back. 

Could you try to run the update using the nRF Connect for Mobile app instead, and share the log output with me? 

Then you should get more information about why the update is failing. 

If you can take a screenshot of the services discovered by the nRF Connect app this could also be helpful. 

Best regards
Torbjørn