how to control beaglebone gpio pins

Question

I'm trying to make a program for beaglebone to let me control the gpio pins. I tried to use sprintf() but doesn't accept input as I know.

I have to re-write couple files in the beaglebone like

gpio export active the pin gpio gpio$pin/direction pin mode in/out gpio gpio$pin/value pin value 1/0

guys..!! just need a idea how to accomplish my goal.

I'm newbie in c++. any information or comment I'll appreciated thks guys for your time.

Solution

Here is a tutorial on using c++ to control the LEDs: http://derekmolloy.ie/beaglebone-controlling-the-on-board-leds-using-c/

Halfway down the page is the C++ code. Take this implementation, but instead of writing to the LED device files, write the appropriate information to the GPIO device files, like in this manual:

http://elinux.org/images/3/33/GPIO_Programming_on_the_Beaglebone.pdf

#include<iostream>
#include<fstream>
#include<string>
using namespace std;

int main(){
   std::fstream fs;

   fs.open("/sys/kernel/debug/omap_mux/gpmc_ad4");
   fs << "7";
   fs.close();
   fs.open("/sys/class/gpio/export");
   fs << "32";
   fs.close();
   fs.open("/sys/class/gpio/gpio32/direction");
   fs << "out";
   fs.close();
   fs.open("/sys/class/gpio/gpio32/value");
   fs << "1"; // "0" for off
   fs.close();
   // select whether it is on, off or flash

   return 0;
}

Comments

[Rufus]

As per here, current version of Beaglebone Black do not use omap_mux. This instruction will not work for newer BBBs

[Rufus]

Refer to this question for configuring pin modes