Serial not working after DFU through BLE and nrfconnect

[Muhammad]

Good day,

I have done DFU using the secure bootloader example in sdk16 using the nrf connect app. The DFU process completes successfully and the controller runs the new application firmware on the device. But I have a strange issue after DFU the serial port stopped working. There is an RFID reader attached to the serial port and stopped working after DFU even we debug the RFID after erasing the controller's flash and bootloader memory then again the serial port did not respond.

My main concern here is:

Is there any impact of the DFU/bootloader on the serial of the controller(nrf52832 chip)?

What should I do to track the issue?

Also when we completed the DFU after the restart we had some prints RTT viewer.

it gives following prints on the RTT viewer.

<info> app: Inside main

00> <debug> app: In nrf_bootloader_init

00> <debug> nrf_dfu_settings: Calling nrf_dfu_settings_init()...

00> <debug> nrf_dfu_flash: Initializing nrf_fstorage_nvmc backend.

00> <debug> nrf_dfu_settings: Using settings page.

00> <debug> nrf_dfu_settings: Copying forbidden parts from backup page.

00> <debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.

00> <info> nrf_dfu_settings: Backing up settings page to address 0x7E000.

00> <debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.

00> <debug> app: Enter nrf_bootloader_fw_activate

00> <info> app: No firmware to activate. 

00> <debug> nrf_dfu_validation: CRC check of app failed. Return 1

00> <debug> app: App is valid

00> <info> nrf_dfu_settings: Backing up settings page to address 0x7E000.

00> <debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.

00> <debug> app: Running nrf_bootloader_app_start with address: 0x00001000

00> <debug> app: Disabling interrupts. NVIC->ICER[0]: 0x0

[Edvin]

Hello,

Is there any impact of the DFU/bootloader on the serial of the controller(nrf52832 chip)?

 There shouldn't be.

Are you completely sure that the application is actually is starting? I see that the log says it is, so I do believe you, but the line CRC check of app failed. Return 1 concerns me. Why did it return this? I see that this function is called from two different places. Can you please check the call stack of the execution of this? Where was it called from?

DFU the serial port stopped working. There is an RFID reader attached to the serial port and stopped working after DFU even we debug the RFID after erasing the controller's flash and bootloader memory then again the serial port did not respond

Have you tried to analyze the UART pins after adding the bootloader using a logic analyzer? Is there any data going on the pins? What GPIOS do you use for the UART?

How do you determine it isn't working? Do you debug? Have you dealt with bootloader settings when you debug? How do you generate the bootloader settings or the DFU image of your application?

Did you do any changes to the bootloader project? Or is it identical to the project in a new unmodified unzip of the SDK, other than the public and private key set? 

I get almost the same log, but in mine it doesn't have the "CRC check of app failed" : 

00> <info> app: Inside main
00> 
00> <debug> app: In nrf_bootloader_init
00> 
00> <debug> nrf_dfu_settings: Calling nrf_dfu_settings_init()...
00> 
00> <debug> nrf_dfu_flash: Initializing nrf_fstorage_nvmc backend.
00> 
00> <debug> nrf_dfu_settings: Using settings page.
00> 
00> <debug> nrf_dfu_settings: Copying forbidden parts from backup page.
00> 
00> <debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.
00> 
00> <info> nrf_dfu_settings: Backing up settings page to address 0x7E000.
00> 
00> <debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.
00> 
00> <debug> app: Enter nrf_bootloader_fw_activate
00> 
00> <info> app: No firmware to activate.
00> 
00> <debug> app: App is valid
00> 
00> <info> nrf_dfu_settings: Backing up settings page to address 0x7E000.
00> 
00> <debug> nrf_dfu_settings: Destination settings are identical to source, write not needed. Skipping.
00> 
00> <debug> app: Running nrf_bootloader_app_start with address: 0x00001000
00> 
00> <debug> app: Disabling interrupts. NVIC->ICER[0]: 0x0
00> 

Sorry, this was a bit messy. A short summary:

1: Any changes in the bootloader project?

2: Callstack to "CRC check of app failed. Return 1"?

3: Did you analyze the UART after adding the bootloader?

4: How do you upload your application? Have you tried to debug the application after adding the bootloader? If not, are you sure that it is the UART that doesn't work, and that there aren't any other bugs in the application causing it to stop before it reaches the UART part? Are you able to see any logging from the application?

Best regards,

Edvin

[Muhammad]

Hi,

I have connected an RFID reader to the microcontroller and my board is also custom. Like button 4 of the development kit is used for something else in my custom board. That's why I have changed the button to some other pin to go to DFU mode. and it is working. but the issue is that the UART is not responding when I transmit some data through RFID. 

Now my application performs the DFU successfully and runs the application But the only issue is that the RFID is notr responding.  Should I need to change some configuration for UART in bootloader? if yes what should it be? 

[Edvin]

Have you tried to debug?

Since you talk about RFID and UART as they are the same thing, does your RFID reader use UART to communicate with the nRF? Did you change the UART pins in the application? Did you change them in the bootloader as well?

[Muhammad]

Hi,

Yes the RFID reader uses UART to communicate with nrf.

I have defined the UART pins in my custom application but I think I have not changed it in bootloader, can you guide me how to change it in bootloader?

I mean please guide me what should be the procedure to change the uart pins.

Thank you. 

[Edvin]

Does your bootloader use UART at all? Do you use a serial or a BLE bootloader? If you use a BLE bootloader, then that doesn't affect it. If you use a serial bootloader, then you should look in your function uart_dfu_transport_init() in nrf_dfu_serial_uart.c.

Or do you mean that the UART doesn't work in your application? Have you tried to debug? Does it give any information on why it doesn't work? Does anything else work?