README.rst
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
