Module starts advertising as dfuTarg if BLE disconnects during DFU

RE: Module starts advertising as dfuTarg if BLE disconnects during DFU

SK — Fri, 26 Jul 2019 06:10:47 GMT

okay i changed NRF_DFU_POST_SD_BL_TIMEOUT_MS and NRF_DFU_INACTIVITY_TIMEOUT_MS to 100 ms as it is the least possible value suggested.

Now when i do DFU, it disconnects automatically with DFU operation failed and starts to advertise with the existing application.

Does that mean this timer also accounts to how much time it takes to start the DFU process? Because in that case, setting 100 ms is not possible at all.

RE: Module starts advertising as dfuTarg if BLE disconnects during DFU

Vidar Berg — Fri, 26 Jul 2019 06:00:58 GMT

The bootloader will always reset when the inactivity timer times out and on the following startup, it will either enter DFU mode again or boot the application.

RE: Module starts advertising as dfuTarg if BLE disconnects during DFU

SK — Fri, 26 Jul 2019 01:34:38 GMT

Okay, so minimum that can be is 100 ms. Does it also mean that if there is no application, it will just advertise for 100 ms and turn off?

RE: Module starts advertising as dfuTarg if BLE disconnects during DFU

SK — Fri, 26 Jul 2019 01:16:21 GMT

Hi Vidar Berg,

Thanks a lot! Tested and it works exactly like you said. I wonder if we can make inactivity timer to zero? So it starts advertising the sec there is an incomplete DFU process.

RE: Module starts advertising as dfuTarg if BLE disconnects during DFU

Vidar Berg — Thu, 25 Jul 2019 13:47:33 GMT

Hi,

[quote user=""]Once the DFU process starts, in between, i disconnect the BLE and then reconnect again.[/quote][quote user=""]What i see is that module starts to advertise as DFUBOOT instead. Shouldn't it advertise as ADV1 only since DFU was not completed? Or the behavior i observe here is correct? [/quote]

It sounds like the correct behavior - the device is still in DFU mode waiting for the DFU controller to re-connect and finish the application update to ADV2. However, the bootloader has an inactivity timer with a timeout of 2 minutes (default) so I would expect it to start ADV1 if you don't reconnect and just let it time out.

[quote user=""]My understanding is that once DFU starts, bootloader will store the incoming image to a different memory and after post validation only it will overwrite the previous application image with a new one. (DUAL BANK UPDATE)[/quote]

Yes, that is correct.