Slow DFU Process

[Aftab]

Hello,

I'm using SDK5 v16.0 and softdevice S140 v7.0.1. 

At some of the PCs, it takes much longer than usual to upload the zip package. On my machine, the transfer rate is 8kB/s while on my colleague's PC it's not more than few hundred bytes/s. So it makes painfully long periods to update one device. Also, on his machine, the device never starts the app and always shows "DfuTarg" which means app.hex was not uploaded properly.

Any suggestion about this?

[Hung Bui]

Hi Aftab, 

Which tool did you use on PC to perform the DFU ? Which bootloader did you use  ? 

[Aftab]

nRFConnect is being used with nRF52840 dongle. Following bootloader is being used:

nRF5_SDK_16.0.0_98a08e2\examples\dfu\secure_bootloader\pca10056_s140_ble

[Hung Bui]

Thanks for the information. 
We need to find out what exactly cause slower communication. 
Can you capture a sniffer trace when you do DFU on a fast and one on a slow computer ? 
Have you tried to test doing DFU from a phone, for comparison  ? 

There are 2 things can cause the slow DFU update, one is the connection interval, and second is the notification setting (the confirmation on every N packets) 

[Ron]

Hey,

If I have a similiar problem, sometimes the OTA is slower, usually using nRF Connect it is fast, but sometimes it also slows down with nRF Connect.

This is an example of a slow nRF Connect OTA

Are the PRN and connect interval not fixed values? why would it change, and so dramatically, within the process? why would there be such differences between runs with the same application on both sides?

If I get sniffer logs what should I look for?

What kind of improvements can I make to my settings to get faster?

Thanks!