SerialException: Could not open port /dev/ttyS0 [Errno 13] Permission denied: '/dev/ttyS0'

[tompreston]

Picture of the issue: https://twitter.com/sezzyann72/status/739477225637052416

It looks like permissions on /dev/ttyS0 are not set up correctly. When you type:

ls -l /dev/ttyS0

You should get the following readout:

crw-rw---- 1 root dialout 4, 64 Jun  6 10:56 /dev/ttyS0

Also,

groups

should return:

pi adm dialout cdrom sudo audio video plugdev games users input netdev gpio i2c spi

The important group to have is dialout.

This error can usually be fixed with:

sudo apt-get update
sudo apt-get upgrade

I'm opening this issue for discussion.

[mahesh-sankaraiah]

I have updated and upgraded still it is showing
Traceback (most recent call last):
File "serial_read.py", line 11, in
timeout=1
File "/usr/lib/python2.7/dist-packages/serial/serialutil.py", line 261, in init
self.open()
File "/usr/lib/python2.7/dist-packages/serial/serialposix.py", line 278, in open
raise SerialException("could not open port %s: %s" % (self._port, msg))
serial.serialutil.SerialException: could not open port /dev/ttyS0: [Errno 2] No such file or directory: ' /dev/ttyS0'
this error what i need to do

[Alisa1989]

I had the same problem, make sure that serial port communication is enabled :)

sudo raspi-config
then

• 5 Interfacing Options
• P6 Serial.
  Select NO to Would you like a login console...
  Select YES to Would you like the serial port hardware ...
  It will then show
  The serial login shell is disabled
  The serial interface is enabled
• Ok
• Finish
• Reboot - Yes.

[mpendwavivi]

thank you alisa, it has worked for me