AnsweredAssumed Answered

How To Use GPIO and CAN on i.MX8MM with Yocto

Question asked by Dave Nugent on Aug 7, 2019
Latest reply on Aug 22, 2019 by Dave Nugent

Hey,

 

I am having a bit of trouble trying to control GPIO pins and CAN on the i.MX8MM with Yocto. I can control pins using:

 

echo XX > /sys/class/gpio/export

 

echo "out" > /sys/class/gpio/gpioXX/direction
or
echo "in" > /sys/class/gpio/gpioXX/direction

 

echo 1 > /sys/class/gpio/gpioXX/value
or
echo 0 > /sys/class/gpio/gpioXX/value

 

echo XX > /sys/class/gpio/unexport

 

But I have not been able to find any information on how to actually set an exposed pin (like on the J1003 header). The only information I have seen is to make sure the DTS file is correct, but not how to actually set it, and to use i.MX Pins Tool v6. When I try to select my board in i.MX Pins Tool v6 I get the error

"Disk operation error. Check disk space and write permissions for data folder C:\ProgramData\NXP\mcu_data_v6"

Which does not make sense because I have over 200GB of free space in that disk and no weird write permissions. So I am really not sure where to go for the GPIO.

 

With the CAN I am able to get it all configured in the kernel, set up the CAN bitrate and start it, but I have no idea how to actually send a message. Any help or links to information would be greatly appreciated.

 

Thanks!

 

Dave

Outcomes