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?
Finally got the GPIOs to work. It was an iomuxc thing in the device tree. Thanks to all.
Hi Michael,
I get the same value (16). How did you solve in the device tree?
Regards and thanks,
Goiatz
maybe something wrong with cat?
try to open "value" like a document.
try:
nano value
or
vi value
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
or
echo 0 > /sys/class/gpio/gpio4/value
Regards,
weidong