BLE radio goes silent

RE: BLE radio goes silent

PB — Thu, 25 Aug 2022 11:48:44 GMT

Hello Bendik,

Testing with radio_test_pca_10040.hex the result is pretty much the same as with DTM firmware from the SDK, that is:

Boards which emit BLE will boot and work with DTM and radio_test hex
Board which have issues don't start with DTM and radio_test hex

Best regards

RE: BLE radio goes silent

Bendik Heiskel — Tue, 23 Aug 2022 11:18:12 GMT

Hi,

After downloading the nRF5 SDk you can find the precompiled radio test FW in <InstallFolder>\examples\peripheral\radio_test\hex\

radio_test_pca10040.hex is for the nRF52832 and radio_test_pca10056.hex is for the nRF52840

The usage of the FW is described here:

https://infocenter.nordicsemi.com/topic/sdk_nrf5_v17.1.0/nrf_radio_test_example.html?cp=8_1_4_6_31

Best regards,

Bendik

RE: BLE radio goes silent

PB — Tue, 23 Aug 2022 06:10:42 GMT

Hello Bendik,

These pins will work very well for us as we left UART pins compatible with nRF DK boards. Where could we find the builds? 🙂

RE: BLE radio goes silent

Bendik Heiskel — Fri, 12 Aug 2022 13:35:08 GMT

[quote user="PB"]Will give it a try but is there maybe a precompiled version? [/quote]

There are precompiled versions of the radio test FW in the nRF5 SDK, but these are meant for the development kits. UART is used to configure the radio output, and the precompiled versions are using the default UART pins for the development kits. For the nRF52840 DK and the nRF52DK(nrf52832) the UART TX and RX pins are P0.06 and P0.08 respectively. This may not work for your custom board if these pins are not available.

The nRF5 SDK can be downloaded here:

https://www.nordicsemi.com/Products/Development-software/nRF5-SDK/Download?lang=en#infotabs

RE: BLE radio goes silent

PB — Thu, 11 Aug 2022 13:06:52 GMT

Hello Bendik,

[quote userid="104202" url="~/f/nordic-q-a/90516/ble-radio-goes-silent/381202"]Have you check if the radio test firmware works?[/quote]

Will give it a try but is there maybe a precompiled version? 🙂

[quote userid="104202" url="~/f/nordic-q-a/90516/ble-radio-goes-silent/381202"]Could you try replacing the crystal of a failing device with the crystal from one that's working? It it still doesn't work the crystal is not the problem.[/quote]

We have tried swapping crystals and Cp capacitors and it still didn't work.

RE: BLE radio goes silent

Bendik Heiskel — Thu, 11 Aug 2022 12:49:26 GMT

Hi,

[quote user="PB"]This falling devices are not able to start with DTM Firmware so we're not able to check constant carrier. [/quote]

Have you check if the radio test firmware works?

https://github.com/nrfconnect/sdk-nrf/tree/main/samples/peripheral/radio_test

You can use it to start a constant carrier and measure the frequency accuracy of the 32MHz crystal by measuring the frequency offset from the selected channel of the carrier.

The frequency stability of the crystal is high, which means that the worst case frequency deviation from 32MHz could be 50ppm. The BLE specifications have a limit of 40ppm carrier offset, so a few devices with a bad crystal could be out of spec.

[quote user="PB"]Also we checked 32MHz quartz (along with its Cp capacitors) and replacing it didn't fix the issue.[/quote]

Could you try replacing the crystal of a failing device with the crystal from one that's working? It it still doesn't work the crystal is not the problem.

Best regards,

Bendik

RE: BLE radio goes silent

PB — Thu, 11 Aug 2022 11:14:04 GMT

Hello Bendik,

This falling devices are not able to start with DTM Firmware so we're not able to check constant carrier. They still start on our Firmware, but without any BLE. Also we checked 32MHz quartz (along with its Cp capacitors) and replacing it didn't fix the issue.

The crystal used is ECS (ECS-320-18-33-JGN-TR)

Best regards,
PB

RE: BLE radio goes silent

Bendik Heiskel — Fri, 29 Jul 2022 13:53:53 GMT

Hi,

Have you verified if these failing devices have any output from the radio at all? You can check this using the radio test sample to output a constant carrier signal from the radio, this can then be measured using a spectrum analyzer.

What are the part numbers for the 32MHz crystal used? Is the same part used for both the nRF52840 and the nRF52832?

Best regards,

Bendik