nRF54L15-DK - how to connect to external MCU?

[Alex P]

Dear Team,

I have nRF54L15-DK and my firmware is running fine over there.

Now I want to use nRF54L15-DK to program & debug standalone NRF54L15 on a my custom board.

The custom MCU has SWDIO, SWDCLK, GND and 2V8 exposed in header, but I need to know to which pins on nRF54L15-DK board I should be connecting those outputs to, to allow me programming standalone MCU and debug the outputs via RTT console.

Unfortunately, the drawing at the back of the board is not very helpful as is not specifying where exactly SWDIO and SWDCLK pins are mapped to.

Thanks

[Simonr]

Hi

Like PJ says, P19 is the connector to use. Here is the page in the nRF54L15 DK user guide describing how to program external boards. https://docs.nordicsemi.com/bundle/ug_nrf54l15_dk/page/UG/nRF54L15_DK/program_debug/debug_out_ext_board.html 

Best regards,

Simon

[Alex P]

Hi Simon,

I was able to connect and program external board via P19.

However, when I try to open up J-Link RTT Viewer it is not showing any output on the debug console in SWD connection mode (but when the same firmware runs on DK board it shows output in the same SWD connection mode). 

Is it an expected behaviour and is there any way to obtain RTT console output from the external board?

Thanks

WBR,

Alex

[PjGlasso]

HI there,

So Short answer "YES" 

The TLDR version has a Thread on Seeed Studio Support forum https://forum.seeedstudio.com/t/use-rtt-no-console-required-logging-debugging-and-diagnostics/294544/1 where I use the nRF54L15_DK and P19 connected via the SWD to a nRF54L15 Xiao Sense (IMU) sitting on the Xiao Dev_board with the SWD connected.

I use the RTT viewer and the JLink Commander to connect, Halt, test and set registers of the Xiao and then HIT GO! and I can watch the RTT viewer output of Serial data from the Xiao (power-ON message & debug printF basically.

You got to love this Nordic Platform the stuff just works.

HTH

GL  PJ