Hi, I am doing testing on GPIO of AR7550. By following this page: viewtopic.php?f=179&t=8351&p=34204&hilit=legato+gpio&sid=5a7904c1438f0e9e89724a437160b193#p34204 I can read the GPIO state via /sys/class/gpio/gpio10/value However, when i try to access this directory inside legato application, [code] LE_INFO(“Enter init_gpio”); if (le_dir_IsDir(“/sys/class/gpio/gpio10”)) { LE_DEBUG(“Gpio already initialized”); return; } int fd; int value; fd = open("/sys/class/gpio/gpio10/direction", O_WRONLY); if (fd < 0) { LE_DEBUG("Failed to open gpio10 direction\n"); return; } else { LE_DEBUG("gpio10 direction opened\n"); } write(fd, "in",2); close(fd); fd = open("/sys/class/gpio/gpio10/value", O_RDONLY); if (fd < 0) { LE_DEBUG("Failed to open gpio10 value\n"); return; } else { LE_DEBUG("gpio10 value opened\n"); } read(fd, &value,sizeof(int)); close(fd); LE_DEBUG("gpio10 value = %d\n",value);[/code] It always returns “Failed to open gpio10 value”. Do you know why?

Hiya, It’s been my experience that you need to be root to get access to the hardware. A Legato application runs sandboxed with a non-root user by default. Add the following line to your adef filesandboxed=falseand see if this helps. I’m not in the office now, but will check my settings when I get back. Ciao, Dave

Hiya, Just to confirm, I needed to run my application unsandboxed to get access to the hardware ports. Putsandboxed: falsein your ADEF file to allow this. ciao, Dave

Hi Dave, Thx for your help! It is working now! Thx!

Hiya, Good to hear that your code is running now. Thanks for letting us know you got it working. Ciao, Dave

Hello, I have problem with GPIO42, I am trying to export GPIO42 such way: echo 42 > /sys/class/gpio/export but Legato responds sh: write error: Device or resource busy I have already configured GPIO42 using AT command AT+WIOCFG=42,16,1,1,0,0,0 but i still receive this error, how can I unlock GPIO42?

I am also having this problem with “le_gpioPin42, oT0 - GPIO 1 (pin 24)”, both in code and at a simple command line interface: root@swi-mdm9x15:/sys/class/gpio# echo 42 > export sh: write error: Device or resource busy root@swi-mdm9x15:/sys/class/gpio# on WP7504: My firmware: Firmware: SWI9X15Y_07.11.09.00 r32989 CARMD-EV-FRMWR1 2016/08/11 18:03:20 Bootloader: SWI9X15Y_07.11.09.00 r32989 CARMD-EV-FRMWR1 2016/08/11 18:03:20 Any Thoughts?

read here [image] Problem exporting and accessing GPIO42 Legato Application Framework Hello, I have problem with GPIO42, I am trying to export GPIO42 such way: echo 42 > /sys/class/gpio/export but Legato responds sh: write error: Device or resource busy I have already configured GPIO42 using AT command AT+WIOCFG=42,16,1,1,0,0,0 but i still receive this error, how can I unlock GPIO42?

GPIO access via Legato application

Legato Application Framework

rio99 May 2, 2017, 7:27am 8

read here

Topic		Replies	Views
GPIO high from legato app Legato Application Framework	1	60	March 24, 2026
MangOH red GPIO access with legatoDeveloper studio wp77xx Legato Linux distribution (Yocto project)	9	949	January 10, 2019
Problem exporting and accessing GPIO42 Legato Application Framework	3	1330	January 27, 2017
GPIO available pins Legato Linux distribution (Yocto project)	3	1414	December 11, 2019
Application Faults Upon Adding GPIO Change Event Handler Legato Application Framework	2	1051	December 12, 2017

GPIO access via Legato application

Related topics