Al,

"Anonymous" wrote in message
...
I have a feeling that the TinyTrak3 hasn't kept up with the times and if it
expects to survive it has to be updated to allow operation with the latest
NMEA protocol version and the new USB units.

Unfortunately, whereas "RS-232 and NMEA" are very much a standard, the newer
GPS receivers with USB ports neither all show up as a "standard serial-type
device" nor do they encode NMEA the same way. :-( Updating the TinyTrak to
support USB receivers is a _major_ undertaking... whereas you can talk RS-232
with any old microcontroller (especially at the 4800bps that NMEA typically
uses), I believe that the commercial USB receivers are running full speed
(12Mbps) and there is simply no way to build a full speed USB master (what you
need to talk to one of these receivers) in software alone. I.e., the TinyTrak
would have to change to incorporate a microcontroller containing a USB _host_
(and these are few and far between -- Cypress has one), or it would have to
add a separate chip to perform this function.

OEM GPS modules that spit out RS-232 won't be going away any time soon; even
in 2010 you'll still have no problem getting them.

---Joel Kolstad