Add UARTE in DFU bootloader to update an STM32

[vonRollChristophe]

Hi,

I use the secure BLE Bootloader to update the nRF52840 (with S140).

Now I want to add a UARTE to update the STM32 connected to nRF52.

Do you have a solution to do that? All my tries have not worked.

Thanks for help.

Best regards.

[vonRollChristophe]

Hi,

I use SDK 17.1.0 and S140 7.2.0

Yes, I declare the module with NRF_LIBUARTE_ASYNC_DEFINE ().

I will check the configuration of the SDK, and the module initialization order, and debug in level 0 mode as you said.

Best regards.

Christophe

[vonRollChristophe]

Hi,

There were at least two problems:

1. The application timer should be initialized before the LibUarte

2. The priority of timers was not good regarding the LibUarte priority in sdk_cong.h file.

Now the libuarte is initialized but the problem is the softdevice enabling. It is done in the bootloader function "nrf_dfu_init", but this function is called during DFU process, but the external application update is called in "nrf_bootloader_fw_activate" function and it is called before DFU process.

[Simonr]

Is there a specific reason you use libuarte in your project? I think you could save yourself some trouble if you used the regular UARTE/APP_UART. If you're not doing DFU very often, so that the extra time the "regular UART" uses doesn't matter too much, I don't think libuarte has a lot of advantages here, and it is harder to use.

Also, can you clarify what the current issue is? Is it that the SoftDevice isn't enabled correctly within the DFU_INIT function on your end? What exactly is the error message you're seeing here?

Best regards,

Simon

[vonRollChristophe]

Hi,

Thanks for your help and time.

I use LibUarte because nRF52 communicates with two other microcontrollers, and I found the best solution with examples in the SDK.

The solution works for the application, so I thought that would work with the bootloader to update an STM32. Unfortunately not. After solving the implementation problem, I saw the data was not sent.
Indeed, we will not make DFU very often. So if you have an example of the UARTE/APP_UART integrated into the secure bootloader, I will be pleased to have it.
At the moment, I modified the firmware to test the STM32 update with the application. And that's work almost, but the problem is on the STM32 side.

To clarify the SoftDevice issue. I think the nRF52 event are managed by the SoftDevice, and as it is enable only in DFU part of the bootloader (after application activation), my implementation of the LibUarte in bootloader does not work. I have no error message only no data transmitted by UARTE.
I hope I am cleared because it is not easy to explain a problem.

Best regards.

Christophe

[Simonr]

Hi Christophe

I'm sorry, but we don't have a finished example for it, as the implementation will change based on what the external device here will be, so you're on your own in the implementation itself.

What event is it exactly that you're running into here? Does Libuarte require the SoftDevice to be enabled? If the issue is that the SoftDevice is enabled in the DFU and then trying to be enabled again when the application begins, you should disable it before moving to the application.

Best regards,

Simon