mirror of
https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git
synced 2026-10-28 13:55:08 +03:00
753c33142f
While () and (void) are synonymous in C++, we use () everywhere else so stick to that pattern in examples. Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
59 lines
1.6 KiB
C++
59 lines
1.6 KiB
C++
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
// SPDX-FileCopyrightText: 2023 Kent Gibson <warthog618@gmail.com>
|
|
|
|
/*
|
|
* Example of a bi-directional line requested as input and then switched
|
|
* to output.
|
|
*/
|
|
|
|
#include <cstdlib>
|
|
#include <filesystem>
|
|
#include <gpiod.hpp>
|
|
#include <iostream>
|
|
|
|
namespace {
|
|
|
|
/* Example configuration - customize to suit your situation */
|
|
const ::std::filesystem::path chip_path("/dev/gpiochip0");
|
|
const ::gpiod::line::offset line_offset = 5;
|
|
|
|
} /* namespace */
|
|
|
|
int main()
|
|
{
|
|
/* request the line initially as an input */
|
|
auto request = ::gpiod::chip(chip_path)
|
|
.prepare_request()
|
|
.set_consumer("reconfigure-input-to-output")
|
|
.add_line_settings(
|
|
line_offset,
|
|
::gpiod::line_settings().set_direction(
|
|
::gpiod::line::direction::INPUT))
|
|
.do_request();
|
|
|
|
/* read the current line value */
|
|
::std::cout << line_offset << "="
|
|
<< (request.get_value(line_offset) ==
|
|
::gpiod::line::value::ACTIVE ?
|
|
"Active" :
|
|
"Inactive")
|
|
<< " (input)" << ::std::endl;
|
|
|
|
/* switch the line to an output and drive it low */
|
|
request.reconfigure_lines(::gpiod::line_config().add_line_settings(
|
|
line_offset,
|
|
::gpiod::line_settings()
|
|
.set_direction(::gpiod::line::direction::OUTPUT)
|
|
.set_output_value(::gpiod::line::value::INACTIVE)));
|
|
|
|
/* report the current driven value */
|
|
::std::cout << line_offset << "="
|
|
<< (request.get_value(line_offset) ==
|
|
::gpiod::line::value::ACTIVE ?
|
|
"Active" :
|
|
"Inactive")
|
|
<< " (output)" << ::std::endl;
|
|
|
|
return EXIT_SUCCESS;
|
|
}
|