DFU process completes, but on startup old code is still running

[Riaan]

Dear Nordic,

We are using the NRF52 chip in our products. And as such we need to update the firmware every now and then. When using the tools you guys provide, it works perfect each time.

Unfortunately we got to implement that procedure from within our tool. The protocol is easy enough to implement, and as such I did it over serial and Bluetooth. But I am getting some strange behavior.

I verify the length and CRC, so I know the packet got in there correct. But when I issue the last restart, one out of 20 times the nrf52 starts up with the old firmware.

I did a comparison on the serial port. same commands, slightly different timing. But I cant find any timing requirements for the DFU. I get the reply so I take it it was correct.

Any ideas here?

[Amanda Hsieh]

Hi Riaan, 

What version of the SDK you are using?

I did a comparison on the serial port. same commands, slightly different timing.

Could you elaborate more about the "slightly different timing"?

Is it possible to provide the debug log when it fails to update the new firmware?

-Amanda H.

[Riaan]

Hi I am using SDK17

When I say slightly different timing, I mean that there are internal timing differences between the nordic app and my app. Same command, but the delays between commands are different.

I can provide you with my own log as generated by the ble app I wrote. Not sure what they will show, but I maybe I am missing a packet.

Will generate some nicer output and attach it.

[Riaan]

So I tried putting together some output that will show what I do, and not be over complicated. Difficult as lots of commands flow for the update process.

What I can do is send you the file (C#) that I use to preform the update process. The code is pretty self explanatory.

Do you Have an email address I can send it to?

[Amanda Hsieh]

You can upload to here via Insert -> Image/video/file 

-Amanda H.