[Lazarus] Raspberry Pi Debug Digital I/O

Bo Berglund bo.berglund at gmail.com
Sun Jan 24 11:47:42 CET 2016


On Fri, 22 Jan 2016 20:55:59 -0500, Donald Ziesig <donald at ziesig.org>
wrote:

>The application itself must run as root to do digital I/O.  If you don't 
>want to debug using the IDE, you don't have to make the IDE run as root, 
>though, just the app.

I do not think this is necessary!

I am NOT running my RPi2B as any other user than pi and it works just
fine to access the GPIO pins. Both FPC and Lazarus run just fine as pi
user.

The trick is to make sure that pi belongs to the proper groups dealing
with the hardware. You can check this using the command:
cat /etc/group | grep pi

It will list the groups pi belongs to and you will find out if there
are missing groups here. This is what my Pi says:

pi at rpi2-jessie2:~/dev $ cat /etc/group | grep pi
adm:x:4:pi
dialout:x:20:pi
cdrom:x:24:pi
sudo:x:27:pi
audio:x:29:pi
video:x:44:pi
plugdev:x:46:pi
games:x:60:pi
users:x:100:pi
input:x:101:pi
netdev:x:108:pi
spi:x:999:pi
i2c:x:998:pi
gpio:x:997:pi  <== This for GPIO

I never use the NOOBS disk, I always create the start image from the
offiocial Raspbian Jessie image, currently I am on the Nov 2015
release. And the groups above were set from the start on that distro.

-- 
Bo Berglund
Developer in Sweden





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