Native read GPIO pin function.
lazarus / 32-Linux

----------------------------------------------------------------------
pascalbythree · 2023-09-04 14:53

Hey everybody, does anyody know how to convert this procedure to a
read PIN function;

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i     { Swith
SoC pin 17 on: }    gReturnCode := fpsystem('echo "1" >
/sys/class/gpio/gpio17/value');   
LogMemo.Lines.Add(IntToStr(gReturnCode));
as seen in this wiki:

https://wiki.freepascal.org/Lazarus_on_Raspberry_Pi#Native_hardware_ac
cess

i want to use the fpsystem procedure and if you will take a closer
look at te website, it is only described to use by a fpopen

Please reply without using hwiringpi, PX,L etc. I would like to use
native code.


Greets, Wouter van Wegen

To get more response, this is the project photo:



It is because PXL does not compile on my brand new RPI4, and i want to
shift over to native code from here to control upcomming problems...

----------------------------------------------------------------------
ojz0r · 2023-09-04 17:20

Why do you want to use fpsystem call instead of a concrete working
example with fpopen?

----------------------------------------------------------------------
ccrause · 2023-09-04 18:48

I've recently started testing the IOCTL native interface, see e.g.
this discussion on why it is supposed to be a "better" alternative.  A
simple demo using gpio.pas.

----------------------------------------------------------------------
MarkMLl · 2023-09-05 06:22

Quote from: ccrause on September 04, 2023, 08:48:45 pmI've recently
started testing the IOCTL native interface, see e.g. this discussion
on why it is supposed to be a "better" alternative.  A simple demo
using gpio.pas.

Thread at https://forum.lazarus.freepascal.org/index.php/topic,56063.m
sg416733.html#msg416733 applies.

It's better than going through the /sys/class etc. tree, but when I
looked at it the API was far from stable.

*HOWEVER* it's applicable to more than just RPi, and I consider that
to be an important consideration.

MarkMLl