UART DFU MBR example

[Dinkin Uri]

Hi,

I'm trying to use uart dfu mbr example and when I flush boot loader via jlink I see that it write mbr hex file at address 0x0. My main application also started from address 0, should I move it to address MBR_SIZE or this mbr hex file used only for debugging.

[Hung Bui]

Hi Uri, 

The MBR is needed for the bootloader to operate. If your application started from address 0, you would need to move it to MBR_SIZE (0x1000). You can refer to our blinky example made for MBR compatibility \examples\peripheral\blinky\pca10040\mbr. 

[Dinkin Uri]

Hi, I encountered in problem when I send fw image to boot loader, it is crushes after second write request, init packet sent ok, but when i start transfer fw image it boot loader is crushed. Do you know what can be a reason?

[Hung Bui]

Hi, 

Do you have any log from the bootloader and from nrfutil ? 

Have you done any modification to the bootloader ? Have you successfully tested with the stock bootloader example and managed to update for example the blinky example  ? 

[Dinkin Uri]

No I have not log from boot loader. I implemented protocol of boot loader in main processor that connected via uart with processor with boot loader. I send init packet and it is working fine, but when I start to send image boot loader crushes. I modified project to match it to 52805, because nordic does not provide boot loader for this processor, and modifications is not only for size, but I'm sure I implemented the protocol in right way. The problem in boot loader definitions. What can be a problem in boot loader writing firmware? What definitions in sdk_config.h I should to check?

[Hung Bui]

Hi Uri, 
Could you clarify that you are planning to send image from a nRF52 to another nRF52 ?
Which example did you base your DFU master on  ? Have you got a look at my example here ?
I would suggest to test doing DFU from PC or from my example with no modification , just to test and make sure the bootloader on the DFU target works fine. After that you can start to test on your own DFU master.

If it works with my example (or from PC) but not on your DFU master, you can try to record a logic trace on the UART pins and compare what is sent from my example or PC with what you send from your DFU master. 

[Dinkin Uri]

Yes, I try send from nrf52840 that is my master send to nrf52805 via uart. I used your sample to send package and I have the same behavior, your program is stuck after it starts to send image because your code is blocking on uart transfer bit, but init packet is sent ok.

[Hung Bui]

Hi Uri, 
Have you tried to use nRFutil application on PC  to send the same image ? 
Have you done any successful DFU update to your NRF52805 chip ? 

If you can do a DFU update using the nRFUtil you can capture a logic trace of the UART pins. And then do the same with your/my DFU bootloader and compare the two. 

Which error code was thrown after you sent the init packet ? 

[Dinkin Uri]

Hi, the problem is that 805 is not exposed to PC, the only way is via 840. Can I send you project and may be you discover the problem?

[Hung Bui]

Please try to setup a test bench, you can use a NRF52 DK to test receiving image.  

What you are trying to build is quite complex and requires good understanding of the bootloader and the DFU protocol. I don't see any way of achieving that without good debug setup. I would suggest to get very familiar with the UART DFU process, by first testing it with the nrfutil on PC.

[Dinkin Uri]

Ok, thank you. Where can I find uart dfu project for 805?