UART comms. with nRF51-DK

[Ehsan]

I have been developing a program for the nRF51-DK that reads an input value from an analogue input pin and displays this on PuTTY(terminal emulator software) using the UART. Now, I want to design a PCB with the nRF51422 chip on it. If I connect this PCB to the nRF51-DK through P20 to program the chip, will it also be possible to display the analogue input pin values from the PCB on PuTTY via UART? Would I need to make any changes or consider additional connections when I design my PCB? Or would it be done automatically?

Regards, Ehsan.

[Jørgen Holmefjord]

Hi Ehsan,

If you want to send data on the UART interface from your custom board to your computer, you will need a UART connection from your board to the computer. The programming interface does not provide any UART connection. On the nRF5x DK, the interface MCU emulates a USB to UART interface and relays data between nRF5x chip and USB interface.

Another alternative is to use RTT for sending data to the computer. RTT runs over the SWD interface (same interface used to program the chip), and can be used without additional wiring. NRF_LOG module support RTT as the backend for logging data.

Best regards,

Jørgen

[Jørgen Holmefjord]

I'm not aware of any examples in the SDK that use RTT, but it should be sufficient to set the defines in sdk_config.h:

#define NRF_LOG_BACKEND_SERIAL_USES_UART 0
#define NRF_LOG_BACKEND_SERIAL_USES_RTT 1