Bluetooth dongle freezes Raspi


5 posts
by zbicin » Sat Aug 18, 2012 12:05 pm
There are plenty of posts about RasPi hanging when used with a bluetooth dongle. I've also tried to use my Pi with a "famous" Cambridge Silicon Radio chip (this one from the dealextreme). It shows up in hcitool right after plugging in into the Pi, scans well and works generally fine untill I want to connect with my Nokia phone. Unfortunately my Pi is headless (no monitor plugged in, control over ssh), but I'm guessing it's a Kernell NULL pointer problem.

Has anyone fixed this problem yet?

Greets,
Chris
Posts: 7
Joined: Mon Jul 16, 2012 8:29 am
by Solenoid » Wed Feb 06, 2013 10:55 am
I can still confirm the instability with the very same dongle. I've successfully connected to this dongle and transferred data both ways, but it seems every time after closing the connection my Pi crashes.

I also have a headless system and it's very annoying to have to physically power cycle the system. I've enabled the watchdog that takes care of it in case of a serious crash so I can get up and working in 2 minutes... but it's obviously unacceptable and I have no idea on how to fix it.
Posts: 16
Joined: Fri Nov 30, 2012 2:41 pm
by Cloudcentric » Wed Feb 06, 2013 11:30 am
I use a BT USB Dongle plugged into a USB Mains Powered Hub and I have managed to connect my phone AOK

It is branded Sitecom but LSUSB states: Bus 002 Device 004: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)
I know everything about nothing"
Posts: 982
Joined: Fri Sep 14, 2012 9:13 am
by Solenoid » Wed Feb 06, 2013 1:12 pm
Seems like it's a power supply problem, I'll try to bridge the USB to the 5V supply. My RPi is powered by a lab supply at the moment that can give everything the RPi wants, so the only limiting factor can be the RPi USB current limitation (140mA if I'm not mistaken).

Still, having a complete crash because of an underpowered and unresponsive USB device seems like overkill.
Posts: 16
Joined: Fri Nov 30, 2012 2:41 pm
by Solenoid » Wed Feb 06, 2013 5:45 pm
So it wasn't the power supply, my Pi crashes systematically after the connection has been closed. I'm starting to think it's related to the drivers and software... can anybody confirm?

Here's my code in Python that I use to connect to a BT clock that has to be synced once in a day.
Code: Select all
#!/usr/bin/env python

import bluetooth, serial, string
from datetime import datetime

btaddr = "00:11:10:17:02:02"

# start bluetooth if it's not already started
clock = bluetooth.BluetoothSocket(bluetooth.RFCOMM)

# connect to the clock on channel 1
clock.connect((btaddr, 1))

now = datetime.now()

# set time
print "Setting time"
clock.send('s')
clock.send('{:%H%M%S}'.format(now))
clock.recv(64)

# set date (just in case)
print "Setting date"
clock.send('d')
clock.send('{:%d%m%y}'.format(now))
clock.recv(64)

# get the date
clock.send('t')
print clock.recv(64)

# close serial connection
clock.close()
I get the last printf from the clock, but then my Pi restarts. I intend to do a whole BT network with all sorts of stuff, but this just won't do.
Posts: 16
Joined: Fri Nov 30, 2012 2:41 pm