UART communication issue thread

[pavan]

Hi All,

We are trying to interface nRF52840 based custom board, manufactured using Config 6 schematic as the reference, with R-Pi to work as NCP. Please refer to the attached schematic .

 

We found that the RPi was not able to communicate with the custom board, so when we tried to trace UART signal between R-Pi and our custom board as well as nRF-DK (nRF52840-DK 1.0.0), we found following results:

 

S. No.	Test	Result with nRF-DK	Debug mode Result with nRF-DK	Result with Custom board	Debug mode Result with Custom board
1	R-Pi Thread NCP Connectivity.	NCP  Connected	Device Running.	NCP  Not-Connected	Device Running.
2	UART TX Trace On J-Tag Reset without R-Pi connection.	Hex data : 7E 80 06 00 72 FC 57 7E	Device Running.	No data	Device Running.
3	UART TX Trace On Switch Reset without R-Pi connection.	Hex data : 7E 80 06 00 71 67 65 7E	Device Running.	No data	Device Running.
4	UART TX Trace On Power-Reset without R-Pi connection.	Hex data : 7E 80 06 00 70 EE 74 7E	Device Running.	Hex data : 7E 80 06 00 70 EE 74 7E	Device Running.

 

Note: --

    1) NCP firmware PATH:  SDK_DIR\examples\thread\ncp\ftd\uart\pca10056\blank\ses

    2) To verify if UART TX and RX is working, we used: SDK_DIR\examples\peripheral\uart\pca10056\blank\ses, and were able to verify that UART communication was working fine.

    3) UART TX and RX is checked on PIN P0.06 and P0.08 respectively of nRF-DK and custom board.

please suggest 

Thank you

PNordic_nRF52840.pdfavan S K

[pavan]

Hi Hung,

I have updated the details below , waiting for reply. and i am not getting REPLY option to my latest post..

thanks in advance

pavan s k

[Edvin]

pavan said:

and i am not getting REPLY option to my latest post..

 DevZone has this issue sometimes. Just reload the site a couple of times, and it should appear after a while. 

So you have a pullup on RX on the nRF, is that correct?

 

pavan said:

PINs P0.04 and P0.26 are going to 3.3 to 1.8 Voltage level converter.

 Have you tried to analyse the 1.8V part of the UART? Are you sure there are no data there?

Are you using HW Flow Control on the UART? If you are not sure, please let me know.

From your original post. Are you saying that it always works on the custom board when you are running debug mode?

Have you monitored the logging on the NCP application running on your custom board? What does it look like compared to when you run it on the DK?