DFU OTA issue on NRF51822AA

[sidekick]

I'm trying to implement DFU-OTA (Bluetooth transport) for our custom board and currently i'm facing problems in flashing the different elements (softdevice, bootloader, application). I think It's mostly a setup problem.

configuration:

1. Hardware: NRF51822QFAA (256KB flash)
2. Softdevice version: s110, v7.1.0
3. nRFGo studio for flashing: v1.18.0.9
4. Bootloader sample code: From SDK v6.1.0 (nrf51_sdk_v6_1_0_b2ec2e6)
5. Custom application: total size of application (around 30kB)
6. IDE: Keil uVision 5.14

To build bootloader, I've used the sample bootloader (without any modification at the moment, except some include path changes for linking). The bootloader builds fine and I use nRFGo Studio to flash the three elements (softdevice, bootloader and the application). I'm able to successfully flash all the three but when i do the verification of our application using "verify" tab in nRFGo studio, it says "Verification failed". Our custom board also has a LED that turns "ON", when there is some issue with the NRF51822QFAA. I do not know the workings of this feature yet, but the point is that i'm very much sure that there is some problem (maybe one being overwritten or being only written only partially).while flashing these three components

I'm attaching the memory ranges snapshot below, which I see in the Keil uVision for bootloader and our application. Please suggest.

memory layout for bootloder:

memory layout for our application:

Thank you for your help.

[Pektusin]

If you're flashing all three parts using Jlink, it won't work as is. When starts, bootloader checks BANK_VALID_APP variable that is not set in your case. You have few options:

1. Flash SD and bootloader, and write your app over DFU - bootloader will handle BANK_VALID_APP for you.

2. After flashing SD, bootloader and the app, manually program BANK_VALID_APP to 0x01

3. Flash SD and your app only. Your app will start, but DFU obviously won't work without the bootloader.

More details: devzone.nordicsemi.com/.../

[sidekick]

Update: This time I Used ".bin" file (Used fromelf.exe which is part of ARM toolchain) to generate .bin file and also renamed the .bin and .dat file as application.bin and application.dat (nRF Toolbox app suggests naming them as application.(bin|hex|dat). My .dat file contents are (As seen in sublime 3 editor) is: "ffff ffff ffff ffff 0100 feff f109 ") and invoking crc.exe on application.bin generated following: (shown here CRC value for 0xffff seed only)

CRC-CCITT (0xffff) = 0x09F1 / 2545

Steps:

• Erased all (using nrfjprog.exe)
• Program SD using nRF Studio
• Flash bootloader. Using KEIL uVision, J-link and nrfjprog.exe
• Write 0x1 at the address 0x00003fc00 using nrfjprog.exe

Device is advertising as "Dfu Targ". Trying to flash application.bin using nRF Toobox app now gives DFU SERVICE ERROR (6) and a re-attempt gives DFU GATT INTERNAL ERROR(129) :(