Using python with bluetooth to communicate

Question

I'm trying to write a simple program to communicate between the RPi and a bluetooth cellphone. I went with this tutorial: Bluetooth Python tutorial for RPi and was able to connect to the phone and they bounded correctly. Then I wrote this python script:

#! /usr/bin/python
import serial
from protocol import *
from MotorControllerP import *
def startBluetoothServer():
 bluetoothSerial = serial.Serial("/dev/rfcomm1",baudrate=9600)
 print("Bluetooth connected")
 try:
 while 1:
 data = bluetoothSerial.readLine()
 if not data: break
 data = data.decode()
 print("Data received: "+data)
 if data[:3] == Client.INIT_HEY:
 print("Initiallizing connection")
 bluetoothSerial.write((Server.INIT_OK+"\n").enc$
 print("Connection initiallized")
 elif data[:3] == Client.KTHXBYE:
 bluetoothSerial.write(Server.CLOSE.encode())
 exitAndClean()
 elif data[:3] == Client.CUSTOM_MOVE:
 data = str(data)
 formattedData = data.split(",")
 direction = formattedData[1]
 left = formattedData[2]
 right = formattedData[3]
 response = customSpeed(direction,left,right)
 print(direction+","+left+","+right)
 bluetoothSerial.write((str(response)+"\n").enco$
 else:
 print("Command not understood: "+data)
 bluetoothSerial.write(Server.CLOSE.encode())
 except KeyboardInterrupt:
 print("Rage Quit")
 except:
 print("Error happened:",sys.exc_info())
 finally:
 exitAndClean()

The code is supposed to read a command from the BT device and send it to a Motor controller. But I receive this error:

Traceback (most recent call last):
 File "/usr/lib/python2.7/multiprocessing/process.py", line 258, in _bootstrap
 self.run()
 File "/usr/lib/python2.7/multiprocessing/process.py", line 114, in run
 self._target(*self._args, **self._kwargs)
 File "/home/pi/Desktop/Car/RPiCar/BluetoothServer.py", line 7, in startBluetoothServer
 bluetoothSerial = serial.Serial("/dev/rfcomm1",baudrate=9600)
 File "/usr/lib/python2.7/dist-packages/serial/serialutil.py", line 260, in __init__
 self.open()
 File "/usr/lib/python2.7/dist-packages/serial/serialposix.py", line 280, in open
 self._reconfigurePort()
 File "/usr/lib/python2.7/dist-packages/serial/serialposix.py", line 409, in _reconfigurePort
 termios.tcsetattr(self.fd, TERMIOS.TCSANOW, [iflag, oflag, cflag, lflag, ispeed, ospeed, cc])
error: (5, 'Input/output error')

Any thoughts?

• rob: do you get the same message if you run it with "sudo" ?
• Javi: That's the message when I run it with sudo

Answer 1

Possibly you don't have /dev/rfcomm1. I suggest to use python-bluetooth library. Check this: example usage