Console Echo

RE: Console Echo

Kenneth — Tue, 07 May 2024 09:48:15 GMT

Hello,

I can confirm I see the same as you, I must admit I have not used the console. I did try to dig around a bit, but I could not really find how this actually "works" either, I did at the end ask chatgpt if it could provide any insight, and it kind of confirmed what we already see: "When using `console_getline()` in Zephyr, characters are displayed as you type because this function is designed to provide real-time input feedback. It's particularly useful for interactive command-line interfaces where users need immediate feedback as they type their input. This behavior allows users to see what they are typing and correct any mistakes before submitting the input."

Kenneth

RE: Console Echo

David Ormand — Mon, 06 May 2024 16:15:48 GMT

I took the hello_world sample and modified it to use console_getline():

prj.conf:

CONFIG_CONSOLE=y
CONFIG_UART_CONSOLE=y
CONFIG_CONSOLE_SUBSYS=y
CONFIG_CONSOLE_GETLINE=y

(I don't know that the first two lines are necessary; the program works identically without them).

main.c:

#include <stdio.h>
#include <string.h>
#include <zephyr/kernel.h>
#include <zephyr/sys/printk.h>
#include <zephyr/console/console.h>

int main(void)
{
        char *p;
        console_getline_init();
        printf("Hello World! %s\n", CONFIG_BOARD);
        while(1) {
                p = console_getline();
                printf("orig: >%s<\n", p);
        }
        return 0;
}

When I flash the program and attach a terminal, I get output and can enter text and get it back.

But if I set the terminal for "local echo", I get:

So it's clear that Console, or at least console_getline(), is doing remote echo.

RE: Console Echo

Kenneth — Mon, 06 May 2024 15:41:53 GMT

Hello,

Do you have an example project I can try to recreate this? Looking at the code (as you do) I can't seem to find any either, it seems it's for instance through console_putchar(), so can't imagine what else may be doing this.

Kenneth