No bluetooth advertisement is found

RE: No bluetooth advertisement is found

Einar Thorsrud — Fri, 13 Dec 2024 14:42:49 GMT

Hi,

Thank you. We have looked at your design and are giving some feedback on that in the private ticket.

Regarding the issue of no advertising, given that all looks good in the log and advertising is started, I susepct issues with the HFXO. Could it be that it is not properly starting or is oscillatign with wrong frequency?

If you have a spectrum analyzer, you can use the radio test sample and set up a constant carrier. Is the carrier located in the correct channel/frequency?. If you do not have a spectrum analyzer, you can also use the nRF Connect for Dekstop RSSI viewer app to see which channel there is traffic. The outcome of this test woul be if we see any radio TX at all, and if so, if we see it at the right frequency.

If there is no radio Tx acticity, perhaps you can measure on the crystal with an oscilliscope when doing advertising or similar? That will affect the crystal making the frequency off, but we can see if the XO is starting or not.

RE: No bluetooth advertisement is found

danny0007 — Thu, 12 Dec 2024 18:31:45 GMT

Hi Einar,

gerber file is uploaded.

RE: No bluetooth advertisement is found

Einar Thorsrud — Thu, 12 Dec 2024 09:59:39 GMT

Hi,

Please upload the layout as gerber files in the private case as well so that we get a better understanding of your hardware.

RE: No bluetooth advertisement is found

danny0007 — Wed, 11 Dec 2024 16:37:36 GMT

Hi Einar,

our schematic is uploaded here: Nordic DevZone please check it out. Many thanks.

RE: No bluetooth advertisement is found

Einar Thorsrud — Mon, 09 Dec 2024 11:33:07 GMT

Hi,

It is difficult to read the value right of the XOSC32MCAPS registet (0x400045c4) as the calculation includes calibration values that vary from chip to chip, but the key was that if you see this change when you use different CONFIG_SOC_HFXO_CAP_INT_VALUE_X2 values you know you are setting it.

You could try to remove C20 and C30 and replace L6 with a 0 ohm resistor and see if that improves things? Other than that, I would recomend that you submit your design for a review.

PS: Even if the truning is bad, you would normally get something radatd, so that if you place a sniffer or a phone or similar right next to the device, you I would expect you should se something as long as it is advertising.

RE: No bluetooth advertisement is found

danny0007 — Sat, 07 Dec 2024 22:17:20 GMT

I copied the antenna match network from Thingy53, but I'm using a different ceramic antenna.

For the antenna on Thingy53, another 6.8pF cap is used, which doesnt exsit in my design.

This is the antenna I'm using: Johanson Technology 2.45 GHz RF Chip Antenna

because I'm using a different antenna, the match network needs to be changed accordingly.

I think the question now is: how to tuning the match network for my antenna?

RE: No bluetooth advertisement is found

danny0007 — Sat, 07 Dec 2024 13:18:18 GMT

Hi Einar Thorsrud

the naming is really misleading... Please correct me, if I'm wrong.

the code was built for "board_name", it's for non-secure.

When I try to compile it for "board_name_ns", I suppose it's for secure.

I tried these two configurations:

I suppose CL = 8pF, 2*8-4=12

CONFIG_SOC_HFXO_CAP_INTERNAL=y

CONFIG_SOC_HFXO_CAP_INT_VALUE_X2= 24

nrfjprog --memrd 0x400045c4
0x400045C4: 0000010B |....|

does it mean 11pF?

I suppose CL = 10pF(which I'm using), 2*10-4=16

CONFIG_SOC_HFXO_CAP_INTERNAL=y

CONFIG_SOC_HFXO_CAP_INT_VALUE_X2= 32

nrfjprog --memrd 0x400045c4
0x400045C4: 00000112 |....|

does it mean 18pF?

and I tried several other values, no one is working.

here is my RF related schematic

and layout

***********************************************

May I just solve the issue by replacing the crystalls with 32M, 8pF and 32.768K, 9pF? use the same crystalls as on thingy53 board?

Best regards

Danny

RE: No bluetooth advertisement is found

Einar Thorsrud — Fri, 06 Dec 2024 09:35:26 GMT

Hi Danny,

It looks like you are building for non-secure? That is no problem, but as the oscillator registers can only be controlled from secure, that means that they are set from TF-M in that case, so in your application you will see the missing dependency. It will be set from TF-M though, and you can experiment with it and read out the XOSC32MCAPS register using nrfjprog --memrd 0x400045c4 and see that you get a different value by setting it with your prj.conf settings than without it (you may need to power-cycle the device after chanign it to see the difference).

If this does not work, perhaps there are also other issues than the HFXO capacitors. Have you had your hardware (schematics and layout) reviewed by us at Nordic? If not, I suggest you sumitt your design for review so that we can see if it looks good from an RF perspective.

Einar

RE: No bluetooth advertisement is found

danny0007 — Wed, 04 Dec 2024 21:08:16 GMT

Hi Einar Thorsrud ketiljo

Thanks for the reply.

but the post confuses me more.

In the function is capacitance*2-14, but the calculation is talking about capacitance*2-4?

The CL of my 32M crystal is 10pF, so (2*10pF -4pF)= 16 pF

I put these in the prj.conf:

CONFIG_SOC_HFXO_CAP_INTERNAL=y

CONFIG_SOC_HFXO_CAP_INT_VALUE_X2= 32

it can be combiled and flashed, but the result is still the old same. any other comments?

and how can I fix this warning:

Many thanks

Danny

RE: No bluetooth advertisement is found

Einar Thorsrud — Tue, 03 Dec 2024 15:00:54 GMT

Hi,

The crystal should be fine, but you need to adjust the internal load capacitors in the nRF5340. Please see this post for details.

RE: No bluetooth advertisement is found

danny0007 — Mon, 02 Dec 2024 21:03:46 GMT

this is the 32MHz I'm using: ndk_08142018_NX2016SA-32M-EXS00A-CS06465_SS-1389053.pdf

according to the datasheet, CL=10pF.

this is the 32.768KHz c_NX2012SA_STD_MUB_1_e-1317508.pdf CL=12.5pF

shall I change them to other crystals?

RE: No bluetooth advertisement is found

ketiljo — Mon, 02 Dec 2024 12:57:39 GMT

What's the specification for the 32 MHz crystal you're uisng? Espesially the CL value is important. The default value for the internal load caps is set for a crystal with CL = 8pF and you need to adjust this if you're using a different crystal. Else the frequency of the carrier will be out of spec.