Buttonless DFU example : Can't put device to boot mode

[himanshu pande]

Hello Experts,

I am running the following examples to test the DFU bootloader in gcc and eclipse environment.

bootloader_secure/pca10040(Bootloader) and experimental_ble_app_buttonless_dfu(DFU template). My device is nrf52 and I am using nRF5_SDK_12.0.0_12f24da.

I transfer the soft device and the bootloader to the device using nrfgo studio application. Then the board lights up LED's 1 and 3 to indicate it is in bootmode. I transfer the zip for buttonless DFU application using nrf toolbox application on Android app. The image transfers successfully and then when I scan, the see the "Nordic_Template" device available.

So far, so good.

Now to put the device in boot mode, I need to write to the "experimental buttonless DFU service".

However, I dont find any option to do in the nrf Connect android app.

Also, I tried the zip and bootloader provided in this example

This works for me and I am able to put device in boot mode with this bootloader and DFU.zip. Screenshot with files in the above query

In case of SDK provided examples, I am only able to see that service has NOTIFY capability but not WRITE.

So, what is difference between the bootloader and DFU in SDK against the bootloader and DFU in that mentioned example? I also updated my linker file for DFU application as per this thread

Kindly let me know.

[EDIT] : I also added the line char_md.char_props.write = 1; to ble_dfu.c file. Now, I am able to see that Experimental Buttonless DFU service has properties "NOTIFY" and "WRITE" .When I press the arrow marked up in the nrf Connect, the value field changes to "Enter Bootloader" but the device doesn't enter the bootloader mode.

Regards, Himanshu.

[himanshu pande]

I am able to enter the bootloader mode now. I had not enabled the notifications for the service.

Just to sum up the steps:

1. Compile Secure Bootloader example.
2. Flash the softdevice
3. Flash the bootloader.
4. Compile the DFU Template application and transfer it to device using zip file.(I used android device) => Make sure to add

char_md.char_props.write = 1;

to your ble_dfu.c in the function rx_char_add()

5. Now, connect to the device "Nordic_Template" in nrf connect.
6. Enable characteristics and send the value 1 to control.

Voila, device enters bootloader mode without any button press. :)

[bjorn-spockeli]

Happy to hear that you're able to enter bootloader mode using the buttonless example. The known issues with the buttonless example is listed here.