Can't find corresponding pins of gpiochip groups

[joseph 0]

I am trying to communicate between the tinker edge r and another 3d printer board (Duet) via SPI. to do that, one of the steps is to set the GPIO Transfer Ready Pin.

on the Raspberry Pi, In order to identify the GPIO device and pin number,  I can use gpioinfo command  and will show a list of available pins.
the output will provide something like:

gpiochip0 - 58 lines:
...
        line  23:     "GPIO23"       unused   input  active-high
        line  24:     "GPIO24"       unused   input  active-high
        line  25:     "GPIO25"       unused   input  active-high
        line  26:     "GPIO26"       unused   input  active-high
        line  27:     "GPIO27"       unused   input  active-high
...

on the tinker edge doesn't give me any output. and if I try to use for example the command     gpioget gpiochip0 <pin_number>    I get an error message like:   gpioget: error reading GPIO values: No such file or directory

I checked with all the gpio groups that are present in the directory   /sys/class/gpio     and nothing worked.

I would really appreciate your help

BR

 

 

 

[tooz 52]

hello @joseph,

libgpio requires gpio charcter device structure and it's only in kernel 5.0+ releases 

it's not supported on tinker edge r as its kernel version is 4.4

libgpiod - C library and tools for interacting with the linux GPIO character device (gpiod stands for GPIO device) 

Since linux 4.8 the GPIO sysfs interface is deprecated. User space should use the character device instead. This library encapsulates the ioctl calls and data structures behind a straightforward API.

to build communications between tinker edge r and the 3d printer board, please refer to the '40 pin mapping table', sudo vim /boot/config.txt set the pin to =on, save, and reboot