Problem with Logitech Mx900 again

Maksim Yevmenkin maksim.yevmenkin at savvis.net
Mon Jun 20 21:41:43 GMT 2005


Darren,

>>>It does not work in bot WinXP and FreeBSD (works for both 
>>>before), but it still works with native cradle.
>>
>>what do you mean with native cradle? is it some sort of wired 
>>interface? bluetooth usb receiver? or bluetooth usb receiver
>>which os detects as usb mouse (i.e. bluetooth usb receiver with
>>hid proxy feature activated)?
> 
> He would be talking about the bluetooth receiver charging base that
> comes with the MX900.  It proxies Logitech bluetooth mice and keyboards
> as usb devices.

ah, ok. so it is bluetooth usb receiver with 'hid-proxy' feature activated.

>>from what i can see, it looks like the mouse does not like new host. 
>>most hid devices will "lock" on the first device that contacted it.
>>that is why you need to "reset" the mouse to make sure it "forgets"
>>about previous host.
> 
> I use my MX900 and Targus mice in both FreeBSD and Windows XP.
> Rebooting back an forth doesn't break the connection to either.  I would
> guess that the MX900 is sensitive only to the hardware address, since
> both OSes use my notebook's internal bluetooth receiver.

that is what i said, didn't i :) ? let me re-phrase it. bluetooth hid 
devices "remembers" the bd_addr of the first remote bluetooth device 
that contacted it. the subsequent connections will only be accepted from 
(or initiated to) "known" host.

> I have found, however, that something does get broken if use bthidd with
> Windows XP hibernated.  When I bring Windows XP back out of hibernation,
> I have to have the machine search for devices to clear the stale
> connection, then push the connect button on the mouse, search again and
> manually reconnect the mouse.

i think its fine. its probably because bluetooth receiver gets powered 
down and thus looses its state. the software however, does not reset its 
state and still thinks it has active connection.

>>another thing you could try to do is to force paring between 
>>the mouse and pc. you need to know default pin-code for the mouse.
>>check the manual to see if its there, if not - try "0000" - four
>>zeros.
> 
> The MX900 doesn't support pin-based pairing AFAIK.  It "auto-pairs" by
> remembering the last host to which it was connected and restores the
> connection whenever the host shows up.

actually, i'm pretty sure it does. here is the quote from the bluetooth 
hid spec

5.4 Link Level Requirements

5.4.1 Authentication, Pairing, Bonding

Support for authentication, pairing, and bonding routines in hosts and 
applications of Bluetooth Human Interface Devices is optional, although 
authentication is strongly encouraged and encryption is recommended for 
host application programs requiring users to enter sensitive information 
on a Bluetooth keyboard or keypad. It is normally the responsibility of 
the host to initiate security procedures, however HIDs are optionally 
allowed to initiate authentication (after initial pairing, initiated by 
the host, has been completed) to prevent host spoofing. Hosts shall by 
default try the zero PIN code first (0x00, one byte) when requesting 
authentication to a HID. If the device has not been preprogrammed to a 
zero PIN, the authentication will fail, at which time the host can 
prompt the user for the non-zero device PIN code.

thanks,
max


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