Freeing up the serial port

[Kjo]

Hi
I have a raspberry pi B and am trying to free up my serial port. I'm able to do what I need to in "sudo nano /boot/cmdline.txt". But when I try to do what I need to do in "sudo nano /etc/inittab" it says that it is a new file and has no content. I'm totally confused and could really do with some help, thanks.

[MarkHaysHarris777]

But when I try to do what I need to do in "sudo nano /etc/inittab" it says that it is a new file and has no content

Take a look here, then come back and ask if you still have questions.

[DirkS]

Hi
I have a raspberry pi B and am trying to free up my serial port. I'm able to do what I need to in "sudo nano /boot/cmdline.txt". But when I try to do what I need to do in "sudo nano /etc/inittab" it says that it is a new file and has no content. I'm totally confused and could really do with some help, thanks.

If you're running Raspbian then

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sudo raspi-config

Option Advanced / Serial / No should take care of that...

[driff]

This does remove the serial console, but if a python script tries to open the port it complains that the port is already open, I had to close the port before my code would work. I didn't need to do that before a recent reinstall and upgrade to kernel 4.4.8

Here is a snippet of my fixed code:

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import serial

ser = serial.Serial('/dev/ttyAMA0', 115200 , timeout=2) #, write_timeout=2) #blocking time out 2s
try:
  ser.open()
except serial.SerialException as err:
  print err
  print "closing port"
  try:
    ser.close()
    ser.open()
  except serial.SerialException as er2:
   print "failed twice " + er2
print "Opening serial port"

give this output:

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Port is already open.
closing port
Serial port opened

[Kjo]

Thank you so much to all those who haved helped