Are the GPIOs SLOW?

nsmith

Hello,

Im porting a project from Arduino to Omega2. The code runs fine in Arduino.

As a test, I wrote a simple C code to toggle a couple GPIOs as shown for Omega2

 while(1) {
   digitalWrite(PWM_LEFT_PIN,0);
   digitalWrite(PWM_RIGHT_PIN,1);
   usleep(5);
   digitalWrite(PWM_LEFT_PIN,1);
   digitalWrite(PWM_RIGHT_PIN,0);
   usleep(5);
 }

The low level code im using to control the ports is here, called inside digitalWrite()

https://github.com/Patryk27/omega2-gpio

My test code should toggle the port every 5 micro seconds, however when i put it on the scope its closer to 75 microseconds.

Am I doing something wrong?

maybe the uSleep is causing it?

Anybody has Idea?

Thanks

DumTux

Can you profile digitalWrite function only?
Like this,

 while(1) {
   digitalWrite(PWM_LEFT_PIN,0);
   digitalWrite(PWM_LEFT_PIN,1);
 }

With this code, what's the wavelength of output signal on LEFT_PIN ?