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2 months ago, I configured my raspberry to use GPIO. I don't remember exactly what I did, but I do remember needing to configure something to enable GPIO. It worked great.

2 months later and multiple reboots, the code fails on the first 2 line. I'm at a loss to figure out why this is failing. I am suspecting the GPIO are no longer enabled.

I could use some pointer being that I'm a newbie.

var fs = require('fs'),
var valuefd = fs.openSync('/sys/class/gpio/gpio5/value', 'r'),

I run this code with sudo node xxxx and the following error is produced

ENOENT: no such file or directory, open 'sys/class/gpio/gpio5/value'

When I do a sudo ls /sys/class/gpio, I get the following:

export gpiochip0 unexport

I don't see gpio5

When i do a sudo ls /sys/class/gpio/gpio5, I get the following:

ls: cannot access /sys/class/gpio/gpio5: No such file or directory

Any help or suggestions where to poke next would be appreciated.

I'm running the OS that came with the raspberry pi. I believe this is Debian.

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While I am not using pi-gpio, I did experiment with pi-gpio. It would appear a side effect of using pi-gpio.open is to create an entry in /sys/class/gpio/gpio5

I ran sudo node

require('pi-gpio').open(29, 'input', function(err){console.log(err)})

then magically the entry appeared in /sys/class/gpio/gpio5 and my program started working.

  • Because pins manipulated via sysfs must be exported before they can be used: kernel.org/doc/Documentation/gpio/sysfs.txt I.e., you can accomplish the same thing by writing 5 (plus a newline) to /sys/class/gpio/export. – goldilocks Aug 22 '16 at 18:31
  • This question has been bumped to the homepage as its been inactive for a while without an answer being marked as correct. If what you outlined in your answer solved your problem, please mark it as correct. – Darth Vader Feb 5 '17 at 12:14

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