DFU problem with SDK 6.1

[Raghu GS]

Hi , I tried to upload the application firmware using OTA service through MCP, I successfully get connected and the transferring of application hex file also gets successfully initiated but at the end of 99 % of successful transfer, I get a error notification as shown in the below screenshot

ERROR - Disconnected from device, while waiting for response for VALIDATE FIRMWARE IMAGE

SDK used is 6.1 MCP version is 3.10.0.14 Softdevice S110 7.1.0

[Stefan Birnir Sverrisson]

Hi Raghu

Thanks for your question

This is expected. The MCP DFU function is not backward compatible futher than nRF51 SDK 7. The bootloader in SDK 6 does not expect an init packet to be sent with the application image, but the MCP does. You can use the nRFToolbox DFU app for either Android or IOS to transfer application hex file to the SDK 6.1 bootloader.

[GlennEngel]

I have the same problem using MCP 3.10.0.14, Softdevice S110 8.0.0 and what I think is SDK 9. Is this combination expected to work? How do I determine my SDK version? I found I needed the fix described here in order to use MCP to update the bootloader.

[GlennEngel]

I had the same problem with OTA MCP but with different versions of the SDK and Softdevice. The problem turned out to be a bug in the bootloader erase function when preparing a blank area to store the OTA update for a 256K flash device. The fix for this allowed me to use the MCP to update my app and bootloader via OTA once again (as well as fixing DFU update from Android).

See OTA DFU: CRC Error Fixed after re-program bootloader for details.

Even with the above fix, I also needed the fix mentioned in OTA DFU times out and is unreliable for MCP to work every time.

[Raghu GS]

So which version of MCP will not expect an init packet, so that I can upload my application using OTA Service.

[Stefan Birnir Sverrisson]

Im not sure if the early bootloader implementations were supported by MCP for Windows if I remember correctly. If you use Android or IOS nRFToolbox DFU app, it should be backwards compatible for non init packet DFUs