UART is not working on my custom board

[vg7190]

Hi,

I am working on nRF52840 board using Segger Embedded Studio for ARM 3.34a on windows 7 64 bit setup.

I am trying to bring up UART on my custom board.

So as a first step I tried running example UART code available in nRF5_SDK_15.0.0_a53641a

I flashed the code first on nRF52840 Development kit and it's working nicely.

But after changing the pins as per my custom board flashing the same code is giving me communication error.

  #define RX_PIN_NUMBER 31
  #define TX_PIN_NUMBER 5

and I am getting 8 on 40002480 adress.

e.g. 40002480 = 00000008.

Can anyone tell me what is causing this issue?

Let me know if this information is not enough and you want me to upload the UART application code in which I am facing this issues.

[Einar Thorsrud]

Hi,

The register at address 40002480 is ERRORSRC, so 8 is the BREAK flag indicating a break condition ("The serial data input is '0' for longer than the length of a data frame."). Do you have a floating RX pin?