nRF52840-DK can't receive my product bluetooth broadcast signal

[Ming78]

nRF52840-DK  2pcs, one TX broadcast signal software, one RX software. RX can receive TX.

My nRF52840 product 2pcs, one TX broadcast signal software, one RX software. RX can receive TX.

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nRF52840-DK 1pcs， My nRF52840 product 1pcs，the same TX software and RX software.

if nRF52840-DK is TX broadcast signal software, my nRF52840 product can receive the signal.

if my nRF52840 product is TX broadcast signal software, the nRF52840-DK can not receive the signal.

why ? where is the matter ? how to debug ?

Thanks.

[ovrebekk]

Hi

Have you had the schematics and layout of your PCB reviewed by us?

It could be some issue with the hardware that prevents the radio from working properly, such as an incorrectly tuned antenna, or an issue with the crystal oscillator. 

Best regards
Torbjørn

[Ming78]

Hi,

I checked the crystal oscillator, it absolutely same with the 52840 DK.

Please check the attachment as my PCB and SCH document.

Any advice is welcome.

PCB.zip

[Ming78]

PCB & SCH document

[awneil]

Ming78 said:

how to debug

Software: used the debugger to step through your code and ensure that the Tx code is actually executing & working;

Hardware: use spectrum analyser and/or sniffer to very that your product is actually transmitting at all and, if so, what it is transmitting.

and see: https://devzone.nordicsemi.com/f/nordic-q-a/48284/nrf52832-wlcsp-ciaa-rf-do-not-work/191537#191537

[ovrebekk]

Thanks for sharing the files. 

I am not a hardware expert, but based on what I can see the layout needs major rework. 

First off you have moved the RF components far away from the chip, introducing a lot of inductance in the antenna network. Secondly the ground/VDD planes cover the entire matching network area, which will also impact performance.

I suggest you start by reading the following blog on PCB design:
https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/general-pcb-design-guidelines-for-nrf52

Based on that you should do a respin of the design and send the layout to us for review before you get new boards produced. 

Once you have the new design ready please open a new case and attach the Gerbers/schematics, and it will be assigned to one of the hardware experts in support. 

Best regards
Torbjørn