topic Re: imx6ul GPIO in i.MX Processors

imx6ul GPIO

michaelcarrier — Thu, 07 Jan 2016 16:55:39 GMT

I have the imx6ulevk which is running Linux. I need to toggle a gpio from user space but I am having difficulty. I am attempting to read GPIO1_IO04. Using DVM I can measure 3.2 V on this pin. I then go to linux and and do the following: "cd /sys/class/gpio", "echo 4 > export", "cd gpio4", "echo in > direction", cat value. Cat returns 16, huh?????? 16? Should be 1 or zero. Any thoughts?

Re: imx6ul GPIO

LuisCasado — Thu, 07 Jan 2016 17:57:01 GMT

Hello,

You can check this thread: https://community.freescale.com/thread/381277

Luis

Re: imx6ul GPIO

christophertele — Fri, 08 Jan 2016 05:58:19 GMT

maybe something wrong with cat?

try to open "value" like a document.

try:

nano value

vi value

Re: imx6ul GPIO

weidong_sun — Tue, 19 Jan 2016 05:25:29 GMT

Hi,

Try to use the following commands:

echo 4 > /sys/class/gpio/export

echo "out" > /sys/class/gpio/gpio4/direction

echo 1 > /sys/class/gpio/gpio4/value

echo 0 > /sys/class/gpio/gpio4/value

Regards,

weidong

Re: imx6ul GPIO

michaelcarrier — Tue, 19 Jan 2016 21:24:20 GMT

Finally got the GPIOs to work. It was an iomuxc thing in the device tree. Thanks to all.

Re: imx6ul GPIO

goiatzmaser — Mon, 25 Jan 2016 11:29:40 GMT

Hi Michael,

I get the same value (16). How did you solve in the device tree?

Regards and thanks,

Goiatz