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GPIO access

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After reading several threads without success I need to ask again how I can get permission as a "normal" user to use the GPIO pins via my python script:

import time

PIN_NUM = 200

print "GPIO %s" % PIN_NUM

   # check to see if the pin is already exported
   # it isn't, so export it   
   open('/sys/class/gpio/export', 'w').write(str(PIN_NUM))

# set gpiochip198 to output
open(''.join(['/sys/class/gpio/gpio',str(PIN_NUM),'/direction']), 'w').write('out')

for i in range(1000):
   open(''.join(['/sys/class/gpio/gpio',str(PIN_NUM),'/value']), 'w').write("1")
   open(''.join(['/sys/class/gpio/gpio',str(PIN_NUM),'/value']), 'w').write("0")

# remove GPIO87 folder from file system
open('/sys/class/gpio/unexport', 'w').write(str(PIN_NUM))



I get this error:

Traceback (most recent call last):
  File "testGPIO.py", line 17, in <module>
    open(''.join(['/sys/class/gpio/gpio',str(PIN_NUM),'/direction']), 'w').write('out')
IOError: [Errno 13] Permission denied: '/sys/class/gpio/gpio200/direction'


So I tried to add:

SUBSYSTEM=="gpio", ACTION=="add", RUN="/bin/sh -c '\
        chown -R root:gpio /sys/class/gpio && chmod -R 770 /sys/class/gpio;\
        chown -R root:gpio /sys$DEVPATH && chmod -R 770 /sys$DEVPATH\

into /etc/udev/rules.d/90-gpiomem.rules


and yes my username is the GPIO group....


Can someone help me further...thx








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