nRF52-DK UART Communication with RN2903 module(UART Interface)

[npenny01]

RN2903 is LoraWAN module using ASCII Command Interface over UART.

RN2903 is connected with nRF52-DK.

I'm connected uart line tx, rx gnd.(cross connect...)

UART communication is only working well when connected to virtual com port.

When both the RN2903 module and the NRF52 development kit are connected, UART communication is not possible.

However, when the nRF52 development kit is connected to the virtual com port through the serial terminal program, communication works well.

After this communication is activated, communication continue even if the virtual com port is disconnected.

I'm even using pins 11 and 12 instead of TX and RX pins 6 and 8 (nRF52 development kit interface MCU UART line).

I'm using SDK 14.2 and serial example.

 The results are different depending on whether the nRF52 development kit is connected to a virtual com port.

Where is the problem?

hardware? firmware?(nRF52 programming) 

please give me a solution.

[Edvin]

Hello,

 

Do you have another DK that you can run an experiment on? 

With your firmware, try to use the pins 11 and 12, as you already have tried. 

On the other board, erase the board, and plug it into a computer connected to e.g. Termite, putty, or another UART terminal (to monitor traffic).

Then short pins 11 and 12 on the board with the project to pins 6 and 8 on the other, and see if you can see the uart messages, and if the board can detect messages coming in as well.

 

Best regards,

Edvin