Unable to connect with the device on jumping to bootloader, thus no DFU.

[RohanKadam]

Hello,

I got two device with DFU-OTA service enabled (included device manager and dfu related handlers/files; merged the application, dual-bank bootloader, s130, app_valid_setting hex together)

i) nrf51422-DK

ii) Custom board with nrf51822

The DFU-OTA works on DK, but when same code is flashed in my custom board with nrf51822 device fails to begin DFU service.

From Log in nrfConnect app,

• [DFU]Jump to bootloader sent (OpCode = 1, Upload Mode = 4)

• Device disconnects
• [DFU] DFU service started
• [DFU] opening files
• [DFU] connecting to DFU target
• [DFU] gatt=device.connectGatt(autoConnect=false)

At this point the DK gets connected in bootloader mode and DFU starts, whereas my custom board is unable to reconnect which is in bootloader mode.

Is it because custom board nrf51822 has 16kB RAM and nrf51422 has 32kB RAM , thus not enough RAM to begin dual-bank bootloader ?

I have tried changing iRAM1 Size from 0x5F80 to 0x4000 (i.e. 16kB) in application code, should I make the same changes somewhere else also?

[Hung Bui]

Hi Roshan,

Have you tried to run the bootloader only ? Were you able to update your application via DFU OTA ?

Do you have the 32kHz crystal on your board ?

Have you reduced RAM size on the bootloader code also ?

[RohanKadam]

Hello sorry for late reply. I was out of town.

[RohanKadam]

• I tried bootloader only, the device doesn't works.

• Yes I have a 32kHz crystal

• I have reduced application code's and softdevice's RAM size but not bootloader, as I'm directly using hex provided.

[Hung Bui]

@Rohan: Could you explain more detail how did you test the bootloader, which SDK version was that ?

Have you tried to debug the bootloader and step into the code to see where it crahes ? Note that you need to disable code optimization to be able to debug the bootloader ?

I assume you flash the softdevice before you flash the bootloader. Make sure you erase the chip before you test.

[RohanKadam]

Hi, The problem is solved (check link given below for solution).

Thanks for your help.

Link: devzone.nordicsemi.com/.../

I changed the RAM settings for my bootloader and it worked.