1.. zephyr:code-sample:: console_echo
2   :name: Console echo
3   :relevant-api: console_api
4
5   Echo an input character back to the output using the Console API.
6
7Overview
8********
9
10This example shows how the :c:func:`console_getchar` and
11:c:func:`console_putchar` functions can be used to echo an input character
12back to the console.
13
14Requirements
15************
16
17UART console is required to run this sample.
18
19Building and Running
20********************
21
22Build and flash the sample as follows, changing ``nucleo_f401re`` for your
23board. Alternatively you can run this using QEMU, as described in
24:zephyr:code-sample:`console_getchar`.
25
26.. zephyr-app-commands::
27   :zephyr-app: samples/subsys/console/echo
28   :host-os: unix
29   :board: nucleo_f401re
30   :goals: build flash
31   :compact:
32
33Following the initial prompt given by the firmware, start pressing keys on a
34keyboard, and they will be echoed back to the terminal program you are using.
35
36Running on QEMU
37===============
38
39On QEMU you can use the VIRTIO console device. It is already configured in
40Zephyr. To use it, run:
41
42.. zephyr-app-commands::
43   :zephyr-app: samples/subsys/console/echo
44   :board: qemu_x86_64
45   :gen-args: -DDTC_OVERLAY_FILE=virtconsole.overlay -DEXTRA_CONF_FILE=overlay-virtconsole.conf
46   :goals: run
47   :compact:
48
49It is possible to use multiple inputs/outputs at once by configuring them
50in the ``overlay-virtconsole.conf`` file.
51
52* Add ``CONFIG_UART_VIRTIO_CONSOLE_F_MULTIPORT=y`` to enable the
53  multiport feature.
54* Configure more ports using the ``CONFIG_QEMU_EXTRA_FLAGS`` option.
55  Refer to the QEMU manual for details.
56
57Sample Output
58=============
59
60.. code-block:: console
61
62    You should see another line with instructions below. If not,
63    the (interrupt-driven) console device doesn't work as expected:
64    Start typing characters to see them echoed back
65