Using J-Link Virtual Com Port on 10028 DK w/ app_trace

RE: Using J-Link Virtual Com Port on 10028 DK w/ app_trace

Bret Foreman — Fri, 02 Oct 2015 21:47:13 GMT

The Keil RTT stuff is working like a champ. I had to turn off Device Manager logging, which looks to be on in the template app by default. Otherwise, the tutorial got me right up and going.

RE: Using J-Link Virtual Com Port on 10028 DK w/ app_trace

Bret Foreman — Thu, 01 Oct 2015 22:06:48 GMT

Anders,

Here's what happens in the init. This is in app_trace_init:

    const app_uart_comm_params_t comm_params =  
{
    RX_PIN_NUMBER, 
    TX_PIN_NUMBER, 
    RTS_PIN_NUMBER, 
    CTS_PIN_NUMBER, 
    APP_UART_FLOW_CONTROL_DISABLED, 
    false, 
    UART_BAUDRATE_BAUDRATE_Baud38400
}; 
    
APP_UART_FIFO_INIT(&comm_params, 
                   UART_RX_BUF_SIZE, 
                   UART_TX_BUF_SIZE, 
                   uart_error_handle, 
                   APP_IRQ_PRIORITY_LOW,
                   err_code);

Note that flow control appears to be disabled.

I'm basing my code on the BLE template project.

RE: Using J-Link Virtual Com Port on 10028 DK w/ app_trace

Alex — Thu, 01 Oct 2015 07:59:37 GMT

Did you hear about RTT?

RE: Using J-Link Virtual Com Port on 10028 DK w/ app_trace

Anders Strand — Thu, 01 Oct 2015 06:49:17 GMT

Flow control is on by default in most of our example projects. Are you basing your code on one of these? It is set inside uart_init() with the APP_UART_FLOW_CONTROL_ENABLED as the 5th parameter inside the app_uart_comm_params_t struct. This tutorial discussed flow control on the nRF51 DK, as well as various terminal applications.

RE: Using J-Link Virtual Com Port on 10028 DK w/ app_trace

Bret Foreman — Wed, 30 Sep 2015 22:56:52 GMT

If I run app_trace_log in a loop I get occasional random characters in the terminal session. This looks a lot like a baud rate issue but I can't find any mismatch.

RE: Using J-Link Virtual Com Port on 10028 DK w/ app_trace

Bret Foreman — Wed, 30 Sep 2015 22:19:55 GMT

Here are the pin settings for the UART (from pca10028.h):

#define RX_PIN_NUMBER  11
#define TX_PIN_NUMBER  9
#define CTS_PIN_NUMBER 10
#define RTS_PIN_NUMBER 8

I believe these are the correct pins for the UART to talk to the Segger.

RE: Using J-Link Virtual Com Port on 10028 DK w/ app_trace

Bret Foreman — Wed, 30 Sep 2015 22:08:31 GMT

Actually, I'm getting a few '[' characters from time to time, as if the baud rate was wrong. But I notice that app_trace_init is setting UART_BAUDRATE_BAUDRATE_Baud38400, which is the same baud I'm using in tera term.