Due to high demand expect some shipping delays at this time, orders may not ship for 1-2 business days.
0

Help: NRF52840 always power on in DFU mode
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

Help: NRF52840 always power on in DFU mode

by Ashfox on Wed Apr 07, 2021 5:59 am

Hi, with my NRF52840 feather express, I can connect to serial, flash the bootloader, upload a sketch, i.e. blink LED & other sketches work fine too, as long as the PC remains connected.
All is normal until I power cycle, so either disconnect/reconnect to the PC, or power using a 3.7V Battery or USB battery bank,
When the board powers on again, the neopixel is constantly Red, the D3 LED flashes Red, and the program doesn't run. The Blue Conn LED never lights up and the Reset button has no effect.
I checked the power supplies, all are normal. All other hardware was removed.
As mentioned above, I updated the bootloader.
I tired a Factory Reset, by connection D2 to GND during Reset - this appears to work, the Blue Conn LED now Flashes.
After Factory Reset, I flashed the Bootloader and Programme, after power cycle, the same fault continues - always on RED neo-pixel and DFU mode when reconnect to PC.
I think its either a hardware fault or flash memory corruption - is there a way to erase all memory on the NRF52840.
I don't have a J-Link adaptor but could considering buying one if this is going to be a regular occurrence - I plan on using this many of these Feathers.
I have tried everything I can think of, any suggestions welcome.
Thanks

Ashfox
 
Posts: 6
Joined: Fri Jun 19, 2020 5:27 am

Re: Help: NRF52840 always power on in DFU mode

by mikeysklar on Wed Apr 07, 2021 8:22 pm

@Ashfox,

Which utility are you using to flash the bootloader? What version of the bootloader have you been using?

Have you tried the adafruit-nrfutil?

https://learn.adafruit.com/introducing- ... bootloader

mikeysklar
 
Posts: 4120
Joined: Mon Aug 01, 2016 8:10 pm

Re: Help: NRF52840 always power on in DFU mode

by Ashfox on Thu Apr 08, 2021 7:02 am

Hi,
I am using the Arduino IDE to flash the bootloader. I had the problem with version 0.3.2 (feather express) and then updated to version 0.5.0, but the problem still remains.
I was a bit confused on how to use the adafruit-nrfutil stand-alone, the instructions for using the command in windows are too vague for me, I tried using command prompt but I couldn't get it to work, so I went back to using the Arduino IDE and managed to get the 0.5 version flashed.
The instructions for adafruit-nrfutil states "use this command, in the folder", what software am I supposed to use to give this command?
For some reason the Arduino boards package (latest version 0.21) is stuck at 0.3.2 bootloader version, why doesn't this get updated?
Updating the bootloader didn't fix the issue, any other suggestions? Thanks

Ashfox
 
Posts: 6
Joined: Fri Jun 19, 2020 5:27 am

Re: Help: NRF52840 always power on in DFU mode

by mikeysklar on Thu Apr 08, 2021 3:21 pm

@Ashfox,

The Arduino IDE tends to lag on all libraries / boards and bootmanagers. It is not under our direct control in terms of updates so we provide other ways to update such as dropping the UF2 file of the bootloader on the BOOTPY drive devicename or using adafruit-nrfutil.

The adafruit-nrfutil might be worth giving a try for the firmware update just to get used to the process. I was not able to locate any "erase all" type arguments, but the new bootloader does replace the old one. The reason a change to the directory is mentioned is because of the way the zip files is packaged. You download a zip and within that is a hex file and another zip. I grabbed the file to show this more clearly:

Code: Select all | TOGGLE FULL SIZE
$ unzip -d nrf52bootloader feather_nrf52840_express_bootloader-0.5.0.zip
Archive:  feather_nrf52840_express_bootloader-0.5.0.zip
  inflating: nrf52bootloader/feather_nrf52840_express_bootloader-0.5.0_s140_6.1.1.hex 
  inflating: nrf52bootloader/update-feather_nrf52840_express_bootloader-0.5.0_nosd.uf2 
 extracting: nrf52bootloader/feather_nrf52840_express_bootloader-0.5.0_s140_6.1.1.zip
$ cd nrf52bootloader/


You would change to created directory and then flash with a command that looks like this:

Code: Select all | TOGGLE FULL SIZE
$ adafruit-nrfutil --verbose dfu serial --package feather_nrf52840_express_bootloader-0.5.0_s140_6.1.1.zip
 -p /dev/ttyACM0 -b 115200 --singlebank --touch 1200


This is pretty much what the Arduino IDE is running, but it has an older bootloader file.

mikeysklar
 
Posts: 4120
Joined: Mon Aug 01, 2016 8:10 pm

Re: Help: NRF52840 always power on in DFU mode

by Ashfox on Fri May 07, 2021 1:42 pm

Three feather NRF52840 (4062) express boards have developed an unrecoverable fault. Two of these boards were bought recently from Mouser and both have developed the same fault in just a few weeks of use. I previously used the Feather NRF52832 (3406) in the exact same application for several months with no issues.

The issue is as follows: the boards when connected by USB can be programmed and function normally when any sketch is loaded. However when power is removed (i.e. USB disconnected), and then power re-applied (USB or battery), the boards always enter DFU mode and the program doesn’t run. This makes the boards unusable since the program is lost every time power is lost.
I tried everything, factory reset of the NRF52 module, loading different Bootloaders, latest version (5.0) and also reverting to older Bootloaders (3.2); none of this has any effect.

I’m very frustrated, I spent a lot of money over the years on adafruit products and this is the first time I genuinely believe the product is at fault. I have spent many days trying to resolve the issue, searching the Adafruit and Nordic forums, trying out different solutions.

I would like to request replacements, and I’m happy to send back the boards that are faulty.

Ashfox
 
Posts: 6
Joined: Fri Jun 19, 2020 5:27 am

Please be positive and constructive with your questions and comments.