the program just stopped working

[bbbbear]

As I use the api you provided, the program is stopped working after running for a while(15-20 mins.).
I still have no idea how to fix it. As I tried to track the code it shows that it was stopped on this line.
receivedBytes += self.mindwaveMobileSocket.recv(missingBytes)
in _readBytesFromMindwaveMobile of MindwaveMobileRawReader.py
I am using rasberry pi 3 B, the bluetooth is already embeded on the board.

Thank you

[robintibor]

Hmm can you somehow get the error message?

[bbbbear]

There is no error message, the program is not crashing but it seems can not receive or waiting for the bytes from the mindwave. As I tried to set the timed out for receiving, the time out is raised instead.
I don't sure if it was the hardware problem or software problem but I've already tried 2 mindwave, the results still the same. I have not try to change the raspberry pi yet.

[robintibor]

Hm in that case I also don't know what to do besides setting timeout and maybe then reconnecting or sth if timeout error is raised.... but no idea if that would help :/

[bbbbear]

I've already tried to disconnect and re-connect when timed out.
After reconnect, it'll be timed out again in less than a minute.
So I'm thinking if it was a hardware problem.
Which version of RaspberryPi do you use, and did you use an external bluetooth receiver?

[robintibor]

I did not use any RasperryPi, I used my normal laptop with a usb bluetooth dongle/adapter.

[macheteluc]

@robintibor Thanks for your code so much, it helps a lot. @bbbbear We are using RaspberryPi to connect the mindwave mobile, also via the embedded bluetooth. Our previous engineer had a similar disconnecting problem, but he coded with C# with official API and used the usb dongle to connect a desktop. In my memory, he said it's an event loop monitoring, one can add a piece of blocking code or something to keep it stay in.

Before we using Raspberry, we used a STM32 board and a HC05 bluetooth model to connect mindwave mobile, which coded in C, looks like this:

And it worked well.

Currently, we can connect the mindwave mobile by using raspberry pi 3, but the attention and meditation data are all zero. I think we might face the disconnecting problem in the future. So, @bbbbear have you ever had this problem about zero attention and meditation?

[bbbbear]

@macheteluc No, I had never face the problem about the zero attention and meditation problem
It works well as it should except the timed out problem.

[AdairValdivia]

@bbbbear hi men can you giveme a hand? im trying to conect the mindwave mobile mw003 to my raspberry pi 3b but i have an error that says
Could not connect:  (52, 'Invalid exchange') ; Retrying in 5s...
Could not connect:  (77, 'File descriptor in bad state') ; Retrying in 5s...
Could not connect:  (77, 'File descriptor in bad state') ; Retrying in 5s...

And when i try to do in terminal
pi@raspberrypi:~ $ sudo rfcomm connect rfcomm0 20:68:9D:91:DA:9D
Can't connect RFCOMM socket: Invalid Exchange

Pls help that i have trying for long time and dont foun the error

[bbbbear]

@AdairValdivia Umm, it's already long time ago that I can't remember and I don't have raspberry pi now.
Did you try to connect by UI?
As I remember, I can't connect the bluetooth via PyBluez and terminal on UI when it works.
But I can't connect on UI when the terminal and PyBluez works. There might me some conflict that I might accidentally fixed.
I think that I'm familiar with bluetoothctl command when I try to make it works.

[gabe-sr]

@bbbbear Did you solve the problem? I am facing it right now. I was using the same config. as you (mindwave mobile + raspberry pi 3 B). After a while, the console does not refresh as if no data is being streamed. After reconnecting the issue rises in less than a minute (approx. 30 seconds).

[bbbbear]

@gabe-sr
I did roughly solve the problem by modifying the receiving code in MindwaveMobileRawReader.py.

• I set a receive timeout
  original
  def _connectToAddress(self, mindwaveMobileAddress): self.mindwaveMobileSocket = bluetooth.BluetoothSocket(bluetooth.RFCOMM) while (not self._isConnected): try: self.mindwaveMobileSocket.connect( (mindwaveMobileAddress, 1)) self._isConnected = True except bluetooth.btcommon.BluetoothError as error: print "Could not connect: ", error, "; Retrying in 5s..." time.sleep(5)
  modified to
  def _connectToAddress(self, mindwaveMobileAddress): err_count = 0 #self.mindwaveMobileSocket = bluetooth.BluetoothSocket(bluetooth.RFCOMM) while (not self._isConnected): try: self.mindwaveMobileSocket = bluetooth.BluetoothSocket(bluetooth.RFCOMM) self.mindwaveMobileSocket.connect( (mindwaveMobileAddress, 1)) self._isConnected = True self.mindwaveMobileSocket.settimeout(1) except bluetooth.btcommon.BluetoothError as error: err_count += 1 if err_count == 10: print ("Attempt",err_count,"of 10: Could not connect:", error, ";") return False else: print ("Attempt",err_count,"of 10: Could not connect:", error, "; Retrying in 5s...") time.sleep(5) return True
• after the timeout was raised, disconnect and reconnect
  original
  def _readBytesFromMindwaveMobile(self, amountOfBytes): missingBytes = amountOfBytes receivedBytes = "" # Sometimes the socket will not send all the requested bytes # on the first request, therefore a loop is necessary... while(missingBytes > 0): receivedBytes += self.mindwaveMobileSocket.recv(missingBytes) missingBytes = amountOfBytes - len(receivedBytes) return receivedBytes;
  modified to
  def _readBytesFromMindwaveMobile(self, amountOfBytes): missingBytes = amountOfBytes receivedBytes = "" # Sometimes the socket will not send all the requested bytes # on the first request, therefore a loop is necessary... #print('(read)',end='') while(missingBytes > 0): #print('\n(.REQ',missingBytes,')') try: receivedBytes += self.mindwaveMobileSocket.recv(missingBytes) except: print ("\n--- recev timed out! ---",datetime.now()) #receivedBytes += ['\n']*missingBytes print("--- exit time out code ---") print("--- Close connection ---") self.close() time.sleep(1) print("--- Trying to re-connect ---") if (self._connectToAddress(self._mindwaveMobileAddress)): print("--- Connected ---") else: print('Terminating process') os.kill(os.getpid(), signal.SIGKILL) return receivedBytes #time.sleep(10) return receivedBytes #return 170 missingBytes = amountOfBytes - len(receivedBytes) #print('--(GET',len(receivedBytes),',miss',missingBytes,')--',) #print('e-read',end='') return receivedBytes;
  I have no idea how to show you what did I try to change here, so you can read the edited version in the following url.
  My modified version is here https://github.com/bbbbear/Python-Russel-Circumflex/blob/master/mindwavemobile/MindwaveMobileRawReader.py
  I think my code is not good enough but aleast it can roughly overcome the problem, I hope there is a way to write a better code.