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]

PCB & SCH document

[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

[awneil]

ovrebekk said:

the layout needs major rework

Ming78 again, see:

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

Seriously consider using a module - so that all this hard RF stuff is taken care of for you!

[Ming78]

1. How to quickly determine the point of the problem, whether there is a Calibration mode or a debug mode?
2. Debugging the antenna, I hope it can be mandatory to transmit all the time. How can I do this?
3. Bluetooth test, such as EVM, frequency error, power control, where can find the test tools for connecting spectrum analyser devices. and the test scripts？

[awneil]

You need to spend time studying the Product Specification to find what test modes are available on the radio.

Part of your design should have included consideration for how you will debug it, test it, tune it, etc.

Again, Seriously consider using a module !