nRF52840 DTM Can not communicate with my custom device.

[paul0208]

Hi,

My custom board use nrf52840.
I first tested uart function by examples/peripheral/uart/*. It is good.
My board's uart ports are P1.9 for TX, P0.12 for RX.

And then, I modified the nRF5_SDK_17.1.0_ddde560\examples\dtm\direct_test_mode/main.c
But, it is not working with nRF Connect for desktop/Direct Test Mode.
I find " Can not communicate with my custom device." error.

And, I modify TX/RX port in main.c of dtm example to as follow

P0.05	RTS
P0.06	TXD
P0.07	CTS
P0.08	RXD

And compile and upload to nrf52840 DK board.
But, Direct test Mode appl do upgrade nrf52840 DK board firmware to some binary(maybe pre-compiled version by Nordic)
And DTM test is success by your binary.

Wha problem in my product?

BR
Paul

[paul0208]

For DTM, do I have to assign RTS/CTS pin?

[Jared]

Hi,

But, Direct test Mode appl do upgrade nrf52840 DK board firmware to some binary(maybe pre-compiled version by Nordic)
And DTM test is success by your binary.

What do you mean, it works when using the pre compiled binaries on your custom board but it doesn't work when you use your modified code?

paul0208 said:

For DTM, do I have to assign RTS/CTS pin?

Here:

regards

Jared

[paul0208]

Hi, Jared,

My custom board does not use P0.6 and P0.8.
That is way that I did not apply pre-compiled binary on my custom board.

Yes,
I modify this structure for my custom board.

BR
Paul

[paul0208]

When I apply my dtm code to DK board after modify UART config of main.c, it does not work.
"DTM tool" can not detect my DTM S/W on DK board,
DTM tool" try to update the DK with pre-compiled dtm binary. 

"DTM tool" think DK board's F/W is not DTM S/W, even though I program my dtm code to DK board.

[Jared]

Hi,

paul0208 said:

When I apply my dtm code to DK board after modify UART config of main.c, it does not work.

It won't work to switch pins on the DK since P0.06 and P0.08 is connected to the interface chip on the development kit via UART and the interface chip push the data to the USB port, it acts as a UART-to-USB bridge between the interface chip and the nRF52840. Switching pins will therefore not work on the DK. 

You switched the UART pins to the P0.12 and P1.9 and connected CTS and RTS on your custom board and it still didn't work?

Can you tell me how everything is connected to your custom board?

regards

Jared