# WP8548 GPIO34..37 sysfs/Legato

**URL:** <https://forum.sierrawireless.com/t/wp8548-gpio34-37-sysfs-legato/9686>\
**Category:** WP Series\
**Created:** [December 14, 2017, 8:50am UTC](https://forum.sierrawireless.com/t/wp8548-gpio34-37-sysfs-legato/9686 "2017-12-14T08:50:48Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![sdmarshall](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@sdmarshall](https://forum.sierrawireless.com/u/sdmarshall)\
**Post date:** [December 14, 2017, 8:50am UTC](https://forum.sierrawireless.com/t/wp8548-gpio34-37-sysfs-legato/9686/1 "2017-12-14T08:50:48Z")

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Hi,

I have designed a custom PCB housing a WP8548 / WP7603, and stupidly missed the caviat on GPIO34 thru 37 stating only accessible via sysfs/Legato. I have searched high 'n low to find out how I actually do that now that I have connected external inputs to these pins.

This might well be a no-brainer for a experienced linux programmer, but alas I am not…

Could somebody give me a code example that reads the state of these pins within an API please ?

Thank you in advance.

Steve

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<div class="post-metadata">

**Author:** ![sdmarshall](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@sdmarshall](https://forum.sierrawireless.com/u/sdmarshall)\
**Post date:** [December 15, 2017, 5:39am UTC](https://forum.sierrawireless.com/t/wp8548-gpio34-37-sysfs-legato/9686/2 "2017-12-15T05:39:14Z")

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Hi,

For those that have hit this before, here is what I did to solve the issue…

I noticed on the Mangoh forum a post not entirely relating to my issue :-

[forum.mangoh.io/t/controlling-wp … roblem/984](http://forum.mangoh.io/t/controlling-wp-gpio-1-gpio22-problem/984)

I had already for each GPIO I needed applied :-

AT+WIOCFG=\<GPIO#\>,16,0,0,1,0,0

In the AT Command console.

then within the main console I executed from /sys/class/gpio folder :-

echo \<GPIO#\> \> export

where \<GPIO#\> is the GPIO number.

Once I applied the above, I can now use the GPIO’s within my API.

I also tested this re-configure is non-volatile.

Thanks.