Easy-to-use C++ library for the new Linux GPIO API.
- OOP design
- Elegant event handling: automatic or manual
- Finds your desired pin by name (need DT/ACPI support)
- Not limited to a specific hardware platform
- Thread safe
- Doesn't look like Arduino APIs :P
- Linux kernel 4.8+ with new GPIO API (
/dev/gpiochipX) & epoll - Linux kernel 5.4+ to make pullup/pulldown actually working
And reasonably new versions of:
- C++17 compatible compiler
- CMake
Use of the CPM package manager is recommended.
include(cmake/CPM.cmake)
CPMAddPackage(
NAME GPIOPlusPlus
GITHUB_REPOSITORY YukiWorkshop/GPIOPlusPlus
VERSION 0.0.5
)
target_include_directories(your_project PUBLIC ${GPIOPlusPlus_SOURCE_DIR})
target_link_libraries(your_project GPIOPlusPlus pthread)#include <GPIO++.hpp>
using namespace YukiWorkshop;Get all available devices:
std::vector<GPIO::Device> devs = GPIO::all_devices();All operations should be surrounded by try and catch.
The exception type is std::system_error unless otherwise specified.
Open a device by number:
try {
auto d = GPIO::Device(0);
} catch (std::system_error& e) {
// Error handling here
std::cerr << "Oops! " << e.what() << "\n";
}...or by path:
auto d = GPIO::Device("/dev/gpiochip0");...or by label:
try {
auto d = GPIO::find_device_by_label("pinctrl-bcm2835");
} catch (std::logic_error &e) {
// No device with this label
}Basic line operations:
auto line0 = d.line(0, GPIO::LineMode::Input | GPIO::LineMode::PullUp);
printf("Line 0: %s\n", line0.read() ? "HIGH" : "LOW");
auto line1 = d.line(1, GPIO::LineMode::Output);
line1.write(1);Get a line by its name (won't work if it doesn't have one in device tree):
auto line0 = d.line(d.lines_by_name["SDA1"], GPIO::LineMode::Input);Add events:
int handle = d.add_event(2, GPIO::LineMode::Input, GPIO::EventMode::RisingEdge,
[](GPIO::EventType evtype, uint64_t evtime){
std::cout << "Hey man, your pin is HIGH at " << evtime << "\n";
}
);And remove them:
d.remove_event(handle);Automatic events handling:
std::thread t([&](){
d.run_eventlistener();
});And stop them:
d.stop_eventlistener();
t.join();Manual events handling:
int epfd = epoll_create(42);
epoll_event ev;
for (auto &it : d.event_fds()) {
ev.events = EPOLLIN;
ev.data.fd = it;
epoll_ctl(epfd, EPOLL_CTL_ADD, it, &ev);
}
int ep_rc;
epoll_event evs[16];
while ((ep_rc = epoll_wait(epfd, evs, 16, 1000)) != -1) {
if (ep_rc > 0) {
for (uint i=0; i<ep_rc; i++)
d.process_event(evs[i].data.fd);
}
// ...
}No more digitalWrites!! Hurray!!!!!!
LGPLv3