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

[Visti Andresen]

Hi

I have seemingly successfully created a firmware that sends a continuous carrier wave using radio_test.c from nRF5_SDK_12.1.0_0d23e2a/examples/peripheral/radio_test/

And it seems to work great as long as I don't start the BLE stack (the current draw is in the expected rang for the radio running)

As sort for icing on the cake I would however like to enter the radio test mode using a BLE characteristic. Which would also allow the transmit power, frequency and duration of the test to be specified.

When I receive the command to enter test mode I call:

sd_ble_gap_disconnect(service_.conn_handle, BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION) To disconnect the current connection.

I then call sd_ble_gap_adv_stop() To stop the BLE stack from advertising

I even tried to adding some timer based delays, NRF_RADIO->TASKS_DISABLE and calling softdevice_handler_sd_disable()

However the chip reboots whenever I call radio_tx_carrier(power_, 3, frequency_)

As it is possible to coexist with the BLE stack sharing the radio if you time it correctly it should be possible use the radio even after the BLE stack has been activated.

I just seems to be missing some steps in politely asking the BLE stack to deactivate and allow me to enter radio test mode.

Does anyone know what I'm overlooking?

Kind Regards Visti Andresen

[endnode]

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;).

[Hung Bui]

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.