RF Noise during connection to NRF54L15 from windows?

RE: RF Noise during connection to NRF54L15 from windows?

Dairlab — Wed, 09 Jul 2025 07:00:46 GMT

Dear all, sorry for the late reply. We did extensive tests and we think we arrived to a solution.

We installed a brand new NCS setup and managed to have the communication stable with the exact same code. It seems the nrf54l15 is not yet compatible with a pure Zephyr setup (tried even the last stable branch 4.1) and gives the errors aforementioned even using the samples included in the repository (for instance, peripheral_hr). We emphasise, even if strange, that the behaviour is ONLY happening when connecting from Windows. Besides, the "RF noise" we also noticed HCI error 0x23 (“Transaction Collision”) if that could help someone in the debugging.

Thanks everyone for their help.

RE: RF Noise during connection to NRF54L15 from windows?

Simonr — Wed, 04 Jun 2025 11:35:37 GMT

Please follow the nRF Sniffer user guide available here in order to use an nRF DK and Wireshark to do sniffing of BLE packets. The firmware is downloadable here: https://www.nordicsemi.com/Products/Development-tools/nRF-Sniffer-for-Bluetooth-LE

Best regards,

Simon

RE: RF Noise during connection to NRF54L15 from windows?

Dairlab — Tue, 03 Jun 2025 09:57:54 GMT

We are using the exact same code, using main branch of zephyr, only changing the board files.
regarding sniffing the packets, unfortunately we have never done that. If you could kindly point us to some references on how to do it, we will be happy to share the results.

RE: RF Noise during connection to NRF54L15 from windows?

Susheel Nuguru — Tue, 03 Jun 2025 09:21:26 GMT

Just pitching in with my 2 cents here.

[quote user="Dairlab"]1) we tried on NRF52811, Ublox BMD 360 Evaluation board and we don't have any issues (20/20 successful connection from both mobile and windows pc)[/quote]

Are you compiling other SoCs with the same project settings just changing the board files or are you compiling them completely under different SDKs and setups? If you are compiling all these with different SDKs then you are not comparing apples to apples.

The configuration with nRF54L might be different like using different connection parameters, different PHY and probably even using extended adv etc where the other two which are working might not be using.

I would sniff air packets for working and not working setup and try to figure out what is different between the two. I would also suggest you to use some conservative (slow) advertising and connection parameters on nRF54L for tests.

CONFIG_BT_CTLR_PHY_2M=n
CONFIG_BT_CTLR_PHY_CODED=n
CONFIG_BT_CTLR_PHY_LE_1M=y
CONFIG_BT_EXT_ADV=n

But the above are just some examples, more should be revealed when you compare the air packets sniffs.

RE: RF Noise during connection to NRF54L15 from windows?

Dairlab — Mon, 02 Jun 2025 09:50:53 GMT

Dear Simonr, thank you for the reply.

Some details:

1) we tried on NRF52811, Ublox BMD 360 Evaluation board and we don't have any issues (20/20 successful connection from both mobile and windows pc)

2) we tried on NRF54L15DK evaluation board, and we have random RF noise problems, 6 times in 20 connections attempts from two windows PC, 0/20 issues from mobile.

Regarding the fw, we are using a custom one (which we are happy to share privately) but also using NCS sample "peripheral_hr" the behaviour is the same.

Thank you in advance.

RE: RF Noise during connection to NRF54L15 from windows?

Simonr — Tue, 27 May 2025 11:04:38 GMT

Hmm, okay. And this behavior is seen with both the LE explorer and Web Bluetooth apps, correct? Can you try setting up a phone with the nRF Connect app as advertiser/peripheral and see if you see the same kind of connection issues with other peripherals connecting to the Windows PC as well? Potentially if you have I.E. an nRF52 or 53 series DK to test with as well.

Also, can you share what application you've flashed onto the nRF54L15 DK when you're able to reproduce this. Are you using either of the Bluetooth samples in NCS or a custom application?

Best regards,

Simon

RE: RF Noise during connection to NRF54L15 from windows?

Dairlab — Mon, 26 May 2025 15:29:11 GMT

Yes, before posting we tried different PCs and few mobiles. Regarding the range, less than 1 meter in all cases.

RE: RF Noise during connection to NRF54L15 from windows?

Simonr — Mon, 26 May 2025 12:56:48 GMT

What laptop(s) or desktop(s) are you using for testing here exactly? Can you confirm you've tested on more than one specific laptop when reproducing this issue? I don't see a specific reason you should see connection issues with Windows, unless the BLE antenna design on the Windows devices isn't the best. Also, at what range and in what kind of environment are you testing here? Do you see the same range working fine when using Android, iOS or Mac to connect?

Best regards,

Simon