Gpios in Yocto QT Embedded

ChrisG

Hey Guys,

First of all sorry for my English its not my native language. Im kind of a newbie in the Embedded Linux / Qt World so I hope my questions are not to stupid.

Im using an embedded Board with an IMX287 CPU and I have a custom designed Yocto(Poky) with Kernel version 3.17 running on it. I used core-image-sato as Image recipe and have also included qt4-embedded on it. I can compile now own QT Programms with bitbake and run them on my yocto build.

Now my question is : Is there an way to control the GPIOs of the IMX287 within my QT Programm(Maybe an library or something similar)? I've read there is an Qt function called "Qprocess" where I can send console commands to control my GPIOs , but this looks like a strange solution for me.

Thx in advance for your help!

greetings Chris

SGaist

Hi,

It depends a bit on how the GPIOs are seen by your OS e.g. are they accessible through a device in /dev ?

ChrisG

Hi SGaist,
Thx for the fast reply.
Right now I can change the direction of the gpios with commands like this:
example:
echo "139" > /sys/class/gpio/export
echo "in" > /sys/class/gpio/gpio139/direction

When i look in my /dev folder i cant see something like gpio

My /dev folder looks like this:
link text

Sorry again if this answer is not accurate enough, Im a hardware guy ^^

SGaist

sys ? Even better !

You can use QFile to write to export and direction and voila nothing more complicated.

Nop, very good answer :) You can be both guys ;)

ChrisG

Im far away from beeing both guys ^^ Thanks for your Help !
Finally got an LED to blink (YAY!). Had some Issues with the Opening Mode of the Qfile . Its only working with OpenMode "WriteOnly" right now.

SGaist

There's always a beginning ;)

IIRC sysfs can provide write-only files