GPS mouse

Practically all GPS mouses are USB these days. How tough
would it be to connect such a device to a microcontroller?
Of course, the uC would only need to be able to handle
the communication with the GSP mouse.

-- 
Thanks, Frank.
(remove 'x' and 'invalid' when replying by email)

In article <41703bff$0$78279$e4fe514c@news.xs4all.nl>, 
f.bemelmanx@xs4all.invalid.nl says...
> Practically all GPS mouses are USB these days. How tough
> would it be to connect such a device to a microcontroller?
> Of course, the uC would only need to be able to handle
> the communication with the GSP mouse.
> 

Not very easy.  It requires implementing a USB host controller---
which is much more complex than implementing a device controller
like that in the GPS mouse.  It would probably be less costly
to buy a naked GPS module for $80 to $100,  add an antenna,
and work with the CMOS levels from the module.  All you would
have to do is then interpret the NMEA strings coming into
a serial port on your microcontroller.

Mark Borgerson

In article <41703bff$0$78279$e4fe514c@news.xs4all.nl>, "Frank Bemelman" <f.bemelmanx@xs4all.invalid.nl> wrote:
>Practically all GPS mouses are USB these days. How tough
>would it be to connect such a device to a microcontroller?
>Of course, the uC would only need to be able to handle
>the communication with the GSP mouse.

Every one of these devices that I've seen has some kind of serial-to-USB 
bridge inside of it, like the Prolific PL-2303 or some other equivalent. The 
GPS module itself outputs regular serial NMEA data and then this goes into the 
bridge chip. On the PC side you install a driver for the USB bridge chip that 
"emulates" a standard serial port under Windows. 

If you're willing to open up the plastic case then you should be able to get 
access at the serial Tx Rx and 1PPS lines. In this case interfacing to a 
microcontroller is pretty straightforward. If you want to do this without 
opening up the plastic case then the task becomes either very difficult or 
virtually impossible if you can't obtain the interface specification document 
for the given bridge chip.

--Tom.

Tom wrote:

> In article <41703bff$0$78279$e4fe514c@news.xs4all.nl>, "Frank Bemelman"
> <f.bemelmanx@xs4all.invalid.nl> wrote:
>>Practically all GPS mouses are USB these days. How tough
>>would it be to connect such a device to a microcontroller?
>>Of course, the uC would only need to be able to handle
>>the communication with the GSP mouse.
> 
> Every one of these devices that I've seen has some kind of serial-to-USB
> bridge inside of it, like the Prolific PL-2303 or some other equivalent.
> The GPS module itself outputs regular serial NMEA data and then this goes
> into the bridge chip. On the PC side you install a driver for the USB
> bridge chip that "emulates" a standard serial port under Windows.
> 
> If you're willing to open up the plastic case then you should be able to
> get access at the serial Tx Rx and 1PPS lines. In this case interfacing to
> a microcontroller is pretty straightforward. If you want to do this
> without opening up the plastic case then the task becomes either very
> difficult or virtually impossible if you can't obtain the interface
> specification document for the given bridge chip.


Some USB connected mice and keyboards I have seen, for PC's, have arrived 
with an adaptor that connects the USB device to a PS/2 input. Without going 
into the specifics of this adaptor I do not know if it of any help. Perhaps 
a search in RS, Farnell, Videk or similar places might locate a suitable 
adaptor for you.

-- 
********************************************************************
Paul E. Bennett ....................<email://peb@a...>
Forth based HIDECS Consultancy .....<http://www.amleth.demon.co.uk/>
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********************************************************************

On Sat, 16 Oct 2004 07:51:44 +0100, "Paul E. Bennett" <peb@amleth.demon.co.uk> wrote:

>Tom wrote:
>
>> In article <41703bff$0$78279$e4fe514c@news.xs4all.nl>, "Frank Bemelman"
>> <f.bemelmanx@xs4all.invalid.nl> wrote:
>>>Practically all GPS mouses are USB these days. How tough
>>>would it be to connect such a device to a microcontroller?
>>>Of course, the uC would only need to be able to handle
>>>the communication with the GSP mouse.
>> 
>> Every one of these devices that I've seen has some kind of serial-to-USB
>> bridge inside of it, like the Prolific PL-2303 or some other equivalent.
>> The GPS module itself outputs regular serial NMEA data and then this goes
>> into the bridge chip. On the PC side you install a driver for the USB
>> bridge chip that "emulates" a standard serial port under Windows.
>> 
>> If you're willing to open up the plastic case then you should be able to
>> get access at the serial Tx Rx and 1PPS lines. In this case interfacing to
>> a microcontroller is pretty straightforward. If you want to do this
>> without opening up the plastic case then the task becomes either very
>> difficult or virtually impossible if you can't obtain the interface
>> specification document for the given bridge chip.
>
>
>Some USB connected mice and keyboards I have seen, for PC's, have arrived 
>with an adaptor that connects the USB device to a PS/2 input. Without going 
>into the specifics of this adaptor I do not know if it of any help. Perhaps 
>a search in RS, Farnell, Videk or similar places might locate a suitable 
>adaptor for you.

These would not be useful - they are just pinout adaptors, and the devices they are supplied with
have firmware which knows how to speak both USB and PS2.

Now what would be interesting would be a USB-RS232 bridge chip that had a 'passthrough' mode to
allow use on RS232 with a suitable adaptor.....

"Tom" <tom8192@hotmail.com> schreef in bericht
news:af1cd.112460$a41.19761@pd7tw2no...
> In article <41703bff$0$78279$e4fe514c@news.xs4all.nl>, "Frank Bemelman"
<f.bemelmanx@xs4all.invalid.nl> wrote:
> >Practically all GPS mouses are USB these days. How tough
> >would it be to connect such a device to a microcontroller?
> >Of course, the uC would only need to be able to handle
> >the communication with the GSP mouse.
>
> Every one of these devices that I've seen has some kind of serial-to-USB
> bridge inside of it, like the Prolific PL-2303 or some other equivalent.
The
> GPS module itself outputs regular serial NMEA data and then this goes into
the
> bridge chip. On the PC side you install a driver for the USB bridge chip
that
> "emulates" a standard serial port under Windows.
>
> If you're willing to open up the plastic case then you should be able to
get
> access at the serial Tx Rx and 1PPS lines. In this case interfacing to a
> microcontroller is pretty straightforward. If you want to do this without
> opening up the plastic case then the task becomes either very difficult or
> virtually impossible if you can't obtain the interface specification
document
> for the given bridge chip.

That may be a reasonable alternative, to open the mouse and remove the
bridge
chip. Have to see if I can find one with screws, or otherwise easy to open.

-- 
Thanks, Frank.
(remove 'x' and 'invalid' when replying by email)

"Mike Harrison" <mike@whitewing.co.uk> schreef in bericht
news:blr1n09tsn0pdu6l5k2gv96kc58j8sn6es@4ax.com...
> On Sat, 16 Oct 2004 07:51:44 +0100, "Paul E. Bennett"
<peb@amleth.demon.co.uk> wrote:
>
> >Tom wrote:
> >
> >> In article <41703bff$0$78279$e4fe514c@news.xs4all.nl>, "Frank Bemelman"
> >> <f.bemelmanx@xs4all.invalid.nl> wrote:
> >>>Practically all GPS mouses are USB these days. How tough
> >>>would it be to connect such a device to a microcontroller?
> >>>Of course, the uC would only need to be able to handle
> >>>the communication with the GSP mouse.
> >>
> >> Every one of these devices that I've seen has some kind of
serial-to-USB
> >> bridge inside of it, like the Prolific PL-2303 or some other
equivalent.
> >> The GPS module itself outputs regular serial NMEA data and then this
goes
> >> into the bridge chip. On the PC side you install a driver for the USB
> >> bridge chip that "emulates" a standard serial port under Windows.
> >>
> >> If you're willing to open up the plastic case then you should be able
to
> >> get access at the serial Tx Rx and 1PPS lines. In this case interfacing
to
> >> a microcontroller is pretty straightforward. If you want to do this
> >> without opening up the plastic case then the task becomes either very
> >> difficult or virtually impossible if you can't obtain the interface
> >> specification document for the given bridge chip.
> >
> >
> >Some USB connected mice and keyboards I have seen, for PC's, have arrived
> >with an adaptor that connects the USB device to a PS/2 input. Without
going
> >into the specifics of this adaptor I do not know if it of any help.
Perhaps
> >a search in RS, Farnell, Videk or similar places might locate a suitable
> >adaptor for you.
>
> These would not be useful - they are just pinout adaptors, and the devices
they are supplied with
> have firmware which knows how to speak both USB and PS2.
>
> Now what would be interesting would be a USB-RS232 bridge chip that had a
'passthrough' mode to
> allow use on RS232 with a suitable adaptor.....

Yes, that would be nice for USB mouse-pointers too. For us poor embedded
guys
it's sort of a nightmare, all this USB stuff.

If these GSP mouses speak PS2 too, I'll look into that. I don't know
anything about PS2, but a 10-seconds google search revealed it's a clock
and bidirectional(?) data. That I can probably understand ;)


-- 
Thanks, Frank.
(remove 'x' and 'invalid' when replying by email)

>"Tom" <tom8192@hotmail.com> schreef in bericht
>news:af1cd.112460$a41.19761@pd7tw2no...
>> In article <41703bff$0$78279$e4fe514c@news.xs4all.nl>, "Frank Bemelman"
><f.bemelmanx@xs4all.invalid.nl> wrote:
>> >Practically all GPS mouses are USB these days. How tough
>> >would it be to connect such a device to a microcontroller?
>> >Of course, the uC would only need to be able to handle
>> >the communication with the GSP mouse.

A fullblown Garmin Etrex GPS receiver costs around $75 , and has RS232
NMEA out , and you can even use it "Standalone"

Carsten