Unable to build project that includes JetsonGPIO using cmake

[fouriearmandt]

Hi All!

I’m working on a simple PID control program for my Jetson Nano 2GB. Using the JetsonGPIO library for C++ from this link, I was able to control my motor using PWM by writing my own makefile and compiling the program.

However, I really want to be able to build and run this project in CLion, which only uses cmake as far as I know. The problem is that I simply can’t get cmake to compile the GPIO library. My CMakeLists.txt file looks like this:

cmake_minimum_required(VERSION 3.10)
project(Motor)

set(THREADS_PREFER_PTHREAD_FLAG ON)
find_package(Threads REQUIRED)
add_compile_options(-pthread -lJetsonGPIO)

set(CMAKE_CXX_STANDARD 14)

add_executable(Motor main.cpp PID/PID.cpp PID/PID.h)

(The reason I really want to use CLion is so that I can debug and step through my code easily).

Any help would be greatly appreciated.

[JerryChang]

hello fouriearmandt ,

may I know what’s the compile error shows?
I’ve never use CLion before, however, Jetson.GPIO is a python library for 40 pin header configuration. for an alternative ways, you may use some general APIs to access the pin.

[fouriearmandt]

Hi Jerry. The error looks like this:

[ 33%] Building CXX object CMakeFiles/Motor.dir/main.cpp.o
[ 66%] Building CXX object CMakeFiles/Motor.dir/PID/PID.cpp.o
[100%] Linking CXX executable Motor
CMakeFiles/Motor.dir/main.cpp.o: In function `main':
main.cpp:(.text+0x250): undefined reference to `GPIO::setwarnings(bool)'
main.cpp:(.text+0x274): undefined reference to `GPIO::cleanup(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
main.cpp:(.text+0x340): undefined reference to `GPIO::setup(int, GPIO::Directions, int)'
main.cpp:(.text+0x350): undefined reference to `GPIO::setup(int, GPIO::Directions, int)'
main.cpp:(.text+0x36c): undefined reference to `GPIO::add_event_detect(int, GPIO::Edge, void (*)(int), unsigned long)'
CMakeFiles/Motor.dir/PID/PID.cpp.o: In function `PID::PID()':
PID.cpp:(.text+0xf0): undefined reference to `GPIO::PWM::PWM(int, int)'
CMakeFiles/Motor.dir/PID/PID.cpp.o: In function `PID::setupPins(bool)':
PID.cpp:(.text+0x1b0): undefined reference to `GPIO::setmode(GPIO::NumberingModes)'
PID.cpp:(.text+0x1c4): undefined reference to `GPIO::setup(int, GPIO::Directions, int)'
PID.cpp:(.text+0x1d8): undefined reference to `GPIO::setup(int, GPIO::Directions, int)'
PID.cpp:(.text+0x1ec): undefined reference to `GPIO::setup(int, GPIO::Directions, int)'
PID.cpp:(.text+0x200): undefined reference to `GPIO::setup(int, GPIO::Directions, int)'
PID.cpp:(.text+0x21c): undefined reference to `GPIO::output(int, int)'
PID.cpp:(.text+0x22c): undefined reference to `GPIO::output(int, int)'
PID.cpp:(.text+0x240): undefined reference to `GPIO::output(int, int)'
PID.cpp:(.text+0x250): undefined reference to `GPIO::output(int, int)'
PID.cpp:(.text+0x260): undefined reference to `GPIO::output(int, int)'
PID.cpp:(.text+0x274): undefined reference to `GPIO::setup(int, GPIO::Directions, int)'
CMakeFiles/Motor.dir/PID/PID.cpp.o: In function `PID::ChangeDutyCycle(float)':
PID.cpp:(.text+0x38c): undefined reference to `GPIO::PWM::ChangeDutyCycle(double)'
CMakeFiles/Motor.dir/PID/PID.cpp.o: In function `PID::setDirection(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)':
PID.cpp:(.text+0x5b0): undefined reference to `GPIO::output(int, int)'
PID.cpp:(.text+0x5c0): undefined reference to `GPIO::output(int, int)'
PID.cpp:(.text+0x5f4): undefined reference to `GPIO::output(int, int)'
PID.cpp:(.text+0x604): undefined reference to `GPIO::output(int, int)'
CMakeFiles/Motor.dir/PID/PID.cpp.o: In function `PID::start(float)':
PID.cpp:(.text+0x6e0): undefined reference to `GPIO::PWM::start(double)'
CMakeFiles/Motor.dir/PID/PID.cpp.o: In function `PID::~PID()':
PID.cpp:(.text+0x1210): undefined reference to `GPIO::cleanup(int)'
PID.cpp:(.text+0x121c): undefined reference to `GPIO::cleanup(int)'
PID.cpp:(.text+0x1228): undefined reference to `GPIO::cleanup(int)'
PID.cpp:(.text+0x1234): undefined reference to `GPIO::cleanup(int)'
PID.cpp:(.text+0x1240): undefined reference to `GPIO::cleanup(int)'
collect2: error: ld returned 1 exit status
CMakeFiles/Motor.dir/build.make:120: recipe for target 'Motor' failed
make[2]: *** [Motor] Error 1
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/Motor.dir/all' failed
make[1]: *** [CMakeFiles/Motor.dir/all] Error 2
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2

This gets generated every time I try to compile the program using CMake. I can compile it just fine with g++ by simply adding the -lJetsonGPIO flag, but for some reason CMake just can’t deal with it. Also I’m aware the JetsonGPIO also exists in python, but I need to use C++ so that version of the library is not an option for me.

[JerryChang]

hello fouriearmandt,

there’re lots of error report undefined reference, this should due to mismatch header file for the function definition.

[fouriearmandt]

Hi Jerry. That’s the problem, yes. I have built and installed the JetsonGPIO library from source. I am able to compile my porgram by writing a simple makefile and compiling with g++. In my main.cpp, all I have to do is add #include <JetsonGPIO.h> and add the -IJetsonGPIO flag when compiling. When using cmake, I get the errors shown above.

[kayccc]

As we updated that we never used CLion, don’t know how to get it work.
May other developers help to share experienecs.

Thanks

[fouriearmandt]

Eventually I figured out how to handle it, though the solution felt really messy. I ended up adding all of the JetsonGPIO files to the project itself and compiling it that way.