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Topic: /dev/ttyUSB0 permission and phpSerial (Read 7471 times) previous topic - next topic

adalgisio

I have issue with phpSerial class and Arduino 10k.

Every time I connect Arduino usb to my pc, I have to set up 777 permission to /dev/ttyUSB0

chmod 777 /dev/ttyUSB0

Otherwhise phpSerial can't access to device.

Is there a way to make permanent this chmod?

Thanks in advamce


peter.vizi

Hi,

Look at the output of ls -l /dev/ttyUSB0, and add the user running your web server to the group who owns this device.

For example on my machine:
 $ ls -l /dev/ttyUSB0
 crw-rw---- 1 root dialout 188, 0 2009-01-23 16:29 /dev/ttyUSB0

owner group: dialout. So now I look at:
 $ ps aux | grep apache
 www-data   803  0.0  0.2 204220  4244 ?        S    Jan21   0:00 /usr/sbin/apache2 -k start

the user www-data runs my Apache:
 $ adduser www-data dialout

Regards, Peter.

adalgisio

done, nothing to do got a bunch of error:

Warning: Specified serial port is not valid in /home/frank/public_html/php_serial.class.php on line 111

Warning: The device must be set before to be open in /home/frank/public_html/php_serial.class.php on line 137

Warning: Device must be opened in /home/frank/public_html/php_serial.class.php on line 541

Warning: Device must be opened to read it in /home/frank/public_html/php_serial.class.php on line 474
0

Warning: Device must be opened in /home/frank/public_html/php_serial.class.php on line 541

Warning: Device must be opened to read it in /home/frank/public_html/php_serial.class.php on line 474
0

Warning: Device must be opened in /home/frank/public_html/php_serial.class.php on line 541

Warning: Device must be opened to read it in /home/frank/public_html/php_serial.class.php on line 474
0

Warning: Device must be opened in /home/frank/public_html/php_serial.class.php on line 541

Warning: Device must be opened to read it in /home/frank/public_html/php_serial.class.php on line 474
0

Warning: Device must be opened in /home/frank/public_html/php_serial.class.php on line 541

Warning: Device must be opened to read it in /home/frank/public_html/php_serial.class.php on line 474

mrmeval

#3
Jan 25, 2009, 01:23 am Last Edit: Jan 25, 2009, 01:24 am by mrmeval Reason: 1
Variation on a theme
http://www.cyberciti.biz/faq/howto-linux-add-user-to-group/

usermod -a -G groupiwant usertoadditto

usermod -a -G dialout www-data

Change the permissions back to something appropriate. The script may need permissions and ownership set as well. I do not recall if Apache sets a scripts permissions to what the script has (within limits) or what  Apache runs at.


adalgisio

it works! tnks...

still remains issue of first null samples..but i think it's caused by autoreset that I have to disable...(DTR to off or hardware mod)

thanks again ;)

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