Command line tracing in Ubuntu

[Matts]

Hi again.

I'm using nRF52 DK board in Ubuntu. I can flash the device with the blinky example (I haven't yet tried the softdevice tough), but I cannot really get any traces out of the SW. I added simple printf to blinky main loop to keep things simple.

JLinkExe -device nrf52 -if swd -speed 4000

SEGGER J-Link Commander V5.10u (Compiled Mar 17 2016 19:06:22) DLL version V5.10u, compiled Mar 17 2016 19:06:19

Connecting to J-Link via USB...O.K. Firmware: J-Link OB-SAM3U128-V2-NordicSemi compiled Mar 15 2016 18:03:17 Hardware version: V1.00 S/N: 682343799 VTref = 3.300V

Type "connect" to establish a target connection, '?' for help J-Link>connect Device "NRF52" selected.

if I run tstart I get:

Trace could not be started, no trace clock.

What is still missing here?

[Matts]

Ok, lets reform the question.

What is the easiest way to try the tracing under linux? I noticed, that there's pretty much no printf:s in other examples than the uart.

I managed to get uart traces out (only to terminal, not via any j-link related tool) from putty-example by adding uart config to example:

const app_uart_comm_params_t comm_params =
{
  RX_PIN_NUMBER,
  TX_PIN_NUMBER,
  RTS_PIN_NUMBER,
  CTS_PIN_NUMBER,
  APP_UART_FLOW_CONTROL_ENABLED,
  false,
  UART_BAUDRATE_BAUDRATE_Baud38400
};
 // Initialize.

APP_UART_FIFO_INIT(&comm_params,
                 UART_RX_BUF_SIZE,
                 UART_TX_BUF_SIZE,
                 uart_error_handle,
                 APP_IRQ_PRIORITY_LOW,
                 err_code);

However when I tried this with any soft device example, no trace is outputted properly (some random characters appear to terminal occasionally). The app_trace_init seems to do same thign with higher bus clock, but that's it.

Is there something in the softdevice that re-routes the uart output? Or is this matter of some makefile setting?

[Matts]

Now it works. const app_uart_comm_params_t comm_params = { RX_PIN_NUMBER, TX_PIN_NUMBER, RTS_PIN_NUMBER, CTS_PIN_NUMBER, APP_UART_FLOW_CONTROL_ENABLED, false, UART_BAUDRATE_BAUDRATE_Baud115200 };

And the main thing was to change the tx buffer size in the file to 2k. apparently the whole system outputs so much trace that it overflows.