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GPIO access on zedboard

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cascade99's picture
cascade99
Junior(0)
GPIO access on zedboard

Hi
According to the following post, GPIO61 is the pin connect to LD6 on Zedboard, but when I try do "echo 61 < /sys/class/gpio/export", but I got error say "sh: write error: No such device", anybody knows which GPIO pin connecting a LED?
Thanks

http://zedboard.org/content/accessing-leds-and-switches-xillinux

TroutChaser's picture
TroutChaser
Moderator(18)
Hello Lynn,

Hello Lynn,
 
You do not link to the post you reference, so it is difficult to know what your ZedBoard design should be doing.
 
LD6 is connected to IO_0 of Bank 33 (pin U19) which is part of the PL (Programmable Logic) section of the Zynq device. It will not be connected to any GPIO until there is a bitstream loaded into the device and then it will depend on the design that generated the bitstream.
 
You also do not mention what version of Linux you are using. There are differing offsets to the GPIO IO depending on the flavor and version of Linux.
 
-Gary

cascade99's picture
cascade99
Junior(0)
Thanks, Gary. I just put the

Thanks, Gary. I just put the link on the first post. Since I don't have any .bit file available yet. Do you know is there GPIO pin which can be controlled by MCU directly? I can access GPIO138/137, but couldn't verify I read/write them correctly.(they are floating I guess).
I'm using petalinux 2014.4

TroutChaser's picture
TroutChaser
Moderator(18)
Hello Lynn,

Hello Lynn,
 
Take a look at the response to your other post here:
 
http://zedboard.org/content/which-gpio-connect-ld9-0
 
If you want a little more detail you might want to look at these forum threads as well:
 
http://microzed.org/content/gpio-offset
 
http://microzed.org/content/zedboard-problem-using-gpio-linux
 
-Gary

cascade99's picture
cascade99
Junior(0)
Hi, Gary

Hi, Gary
I'm still confusing about LD0...LD7, I'm using petalinux 2014.4, which GPIO pin# should I export for LD0?
Thanks

cascade99's picture
cascade99
Junior(0)
Hi, Gary

Hi, Gary
I looked at the link you posted, it looks like pin 65 to 72 is the SW/LED on petalinux?
Thanks