What are the requirements for going from an active BLE connection to sending a carrier wave?

RE: What are the requirements for going from an active BLE connection to sending a carrier wave?

Hung Bui — Fri, 03 Nov 2017 13:45:53 GMT

Hi Visti,

It's not allowed to access the RADIO when the softdevice is still enabled.

If you plan to use the radio for short periord of time (a few hundred milliseconds) and keep the BLE connection for example, You can think of using the Timeslot. Please look for Multiprotocol Support chapter in the Softdevice specification. Here is the tutorial for timeslot.

RE: What are the requirements for going from an active BLE connection to sending a carrier wave?

endnode — Fri, 03 Nov 2017 12:30:31 GMT

Also isolating the behavior into some smaller project where you could share full source code here would give opportunity to debug more efficiently, right now it's just shooting in the dark (over the internet;).

RE: What are the requirements for going from an active BLE connection to sending a carrier wave?

endnode — Fri, 03 Nov 2017 12:27:57 GMT

I believe this function just disables the event handler not SD itself. I was trying to get some example from latest SDK and the only thing I see is ble_stack_stop function in examples\multiprotocol\ble_app_gzll\ble_app_gzll_hr.c. However you have still two more options: look on other Q&S on this forum regarding SD disabling (by quick search it looks there are dozens or rather hundreds of those, just to filter the relevant pieces and finding some recent one which refers to some recent API) or wait if Nordic support team will come and answer this ticket;)

RE: What are the requirements for going from an active BLE connection to sending a carrier wave?

Visti Andresen — Fri, 03 Nov 2017 10:43:37 GMT

Calling softdevice_handler_sd_disable from an app time seems to trigger a reboot

RE: What are the requirements for going from an active BLE connection to sending a carrier wave?

Visti Andresen — Fri, 03 Nov 2017 09:28:59 GMT

I have actually considered using the NVRAM bits as well, we already use one for entering DFU mode and yes I would have to either reduce the complexity / entropy of the settings or store them in flash.

I do however get the feeling that I should be quite close to having the restrictions lifted on the radio.

RE: What are the requirements for going from an active BLE connection to sending a carrier wave?

endnode — Fri, 03 Nov 2017 09:21:25 GMT

If you decide to continue with your architecture then I believe problem is that you are not disabling the SD properly and so you get hard-fault when touching restricted HW block directly.

RE: What are the requirements for going from an active BLE connection to sending a carrier wave?

endnode — Fri, 03 Nov 2017 09:19:48 GMT

As entering radio test will terminate the connection anyway I would simply soft reset the chip and in boot-up procedure read some flag (there are 2 bytes of RAM registers on nRF52 which survive soft reset or alternatively store config in flash) which would say if your should start standard BLE stack and your profile or enter this one-purpose radio test mode. Once you are done with the test sequence according to parameters pushed previously you can again reset your MCU and during boot switch to BLE part.

This looks maybe like a hack on a first sight but I've actually seen this in several production FWs where DTM or radio test were bundled like this to "full" BLE FW functionality and switch was done during boot based on various conditions.