4 years, 2 months ago.

Bootloader image for nRF51822 without an external XC oscillator for FOTA

Hi everyone,

I tried using the Booloader + Softdevice default app (mKIT) found here (https://developer.mbed.org/teams/Bluetooth-Low-Energy/wiki/Firmware-Over-the-Air-FOTA-Updates#default-bootloader) to flash my nRF51822 but it seems to stop working once I do this. I was successfully able to load the bootloader and then load an application image on the device using FOTA for the mKIT itself.

I believe that the problem lies in the fact that the nRF51822 I am using does not have an external oscillator crystal but uses the internal RC oscillator. I was wondering if there is a bootloader dfu default app with the mentioned configuration set, or how I can create one myself.

Any response will be much appreciated.

Best, Anuraag

1 Answer

3 years, 8 months ago.

Did you ever find a solution to this Anuraag? We're seeing the same thing. Used to work fine but seems to no longer support LFCLKSRC of RC.

Hi Kevin, we were able to compile a Bootloader that used an internal LFCLKSRC using the Nordic SDK kit (https://developer.nordicsemi.com/nRF5_SDK/). In our case, we specifically needed Softdevice v7.1.0 therefore we used v7.x.x. In particular, we changed line 156 in /SDKv7.1.0/examples/dfu/bootloader/main.c to SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_SYNTH_250_PPM, true); and recompiled it. Using this bootloader, we were able to run our firmware. I hope this helps. If you are more specific with what your problem is, maybe I could be more useful.

Best, Anuraag

posted by Anuraag Shakya 19 Jul 2016