# GPIO Enable Pull Up

**URL:** <https://forum.sierrawireless.com/t/gpio-enable-pull-up/13207>\
**Category:** FX30\
**Created:** [July 18, 2018, 7:06am UTC](https://forum.sierrawireless.com/t/gpio-enable-pull-up/13207 "2018-07-18T07:06:20Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![tdcxsun](https://avatars.discourse-cdn.com/v4/letter/t/b5e925/32.png) [@tdcxsun](https://forum.sierrawireless.com/u/tdcxsun)\
**Post date:** [July 18, 2018, 7:06am UTC](https://forum.sierrawireless.com/t/gpio-enable-pull-up/13207/1 "2018-07-18T07:06:20Z")

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Hello,

I am trying to configure a GPIO (#56 of FX30) via an application.  
Here are the steps of the configuration : (bindings in adef and cdef files are functional)  
`gpioVeronte_SetPushPullOutput(1, false);`  
`gpioVeronte_EnablePullUp();`

I get the following error :  
`Jan 6 00:36:37 | gpioService[572]/sysfsGpio T=main | gpioSysfsUtils.c WriteSysGpioSignalAttr() 173 | Failed to write up to GPIO config /sys/class/gpio/gpio56/pull. Error Operation not permitted`

Even setting it through ssh does not change anything:

```
root@fx30:~# echo up > /sys/class/gpio/gpio56/pull
sh: write error: Invalid argument
root@fx30:~# config set /sys/class/gpio/gpio56/pull up
root@fx30:~# cat /sys/class/gpio/gpio56/pull
down
root@fx30:~#

```

Is it a known issue of the FX30 ?  
Thank you

---

<div class="post-metadata">

**Author:** ![lotam](https://avatars.discourse-cdn.com/v4/letter/l/958977/32.png) [@lotam](https://forum.sierrawireless.com/u/lotam)\
**Post date:** [July 18, 2018, 1:09pm UTC](https://forum.sierrawireless.com/t/gpio-enable-pull-up/13207/2 "2018-07-18T13:09:49Z")

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Hi tdcxsun,

If refer to table 3-8 of FX30 user guide: [https://source.sierrawireless.com/resources/airlink/hardware\_reference\_docs/airlink\_fx30\_hw\_user\_guide/](https://source.sierrawireless.com/resources/airlink/hardware_reference_docs/airlink_fx30_hw_user_guide/)

GPIO56 (IO3) is digital output.  
To control IO3 internal pull, it should be GPIO54.

Thx