Unable to perform secure serial DFU with nrf52 DK

[Sourabh]

Hi, I'm having trouble performing a secure serial DFU with the nrf52 DK, I'm using the following components :

• SDK 13.0.0 : experimental_bootloader_secure_serial example
• softdevice v4.0.2
• nrfutil v3.2.0(standalone exe)

I've disabled flowcontrol and reduced the baudrate to 9600 as suggested by this post. I still get no ping response error from nrfutil.

nrfutil error message

rtt viewer log

[bjorn-spockeli]

Could you post the nrfutil command you entered to start the serial DFU?

[Sourabh]

I had some issue with my com port, I could get it to work with flow control enabled and baud rate of 115200. But it does not work with flow control disabled and baud rate of 9600. I use the following command : nrfutil dfu serial -pkg dfu_test_app_hrm_s132.zip -p COM1 -fc 0 -b 9600

I get TypeError: 'NoneType' object is not iterable on nrfutil.

[bjorn-spockeli]

I am able to reproduce this here and I get the same result if I try to perform serial DFu with flow control enabled (on both the nRF and PC side), but with the baudrate set to 9600. I have reported this to the developer and I will keep you posted.

[Sourabh]

Are there any updates on how i could use nrfutil with flow control disabled?

[bjorn-spockeli]

@srb0525: There has been some fixes in nrfutil v3.2.1 regarding serial DFU, see this link. Could you try to use this version and see if the issue has been resolved?