CODEWITHSUNDEEP
c++linuxraspberry-piraspbiangpio
user2766296
user2766296

Reputation: 657

GPIO Pins RaspberryPi Using C++

I'm writing a program to control the GPIO pins on my raspberryPi with C++ and having difficulty I'm able to export with the following code:

char pathString[256];
sprintf(pathString, "%s/export", "/sys/class/gpio");
ofstream exporterFile(pathString);
exporterFile << pinNumber;
exporterFile.close()

This works an successfully exports the pin but this does not set the direction:

sprintf(pathString, "%sgpio%d/direction", "/sys/class/gpio", pinNumber);
ofstream directionFile(pathString);
directionFile << pinDirection;
directionFile.close();

For some reason I cannot write to the file, perhaps I do not have the right privileges. My question is, is that the problem and if so how do I solve it so I can write to the file.

Thanks in advance

Upvotes: 1

Views: 2342

Answers (1)

Sami Sallinen
Sami Sallinen

Reputation: 3496

You need to be root or run your program with sudo in order to use the GPIO pins. However, I'd recommend using the wiringpi library http://wiringpi.com/ to access GPIO from c/c++. It is easy to use and raises the abstraction level a bit. It also lets you do things like PWM. A program using wiringpi also needs to be run with sudo.

Upvotes: 3

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