[kismac] Re: GPS Unit for a Powerbook with Airport wnic

  • From: Richard Smith <smith@xxxxxx>
  • To: kismac@xxxxxxxxxxxxx
  • Date: Sun, 27 Apr 2003 13:41:12 -0700

I purchased a Delorme Earthmate -- just released USB version 
(http://www.delorme.com/earthmate/). This was *not* a good idea. 
Although there are USB GPS units that will work with a Mac/OS X, this 
is not one of them.

The problem lies in the way that current software expects to "see" the 
GPS. Everything I have tried expects to see it as a serial device. 
There are no "native" USB implementations of the NMEA data that comes 
from the device, as far as I can tell. And the Delorme Earthmate, which 
uses a Cypress Semiconductor USB chipset, does not have Mac serial 
drivers. They do provide Windows serial drivers, and other GPS units, 
based on alternative USB chipsets, have a serial driver available. One 
of the driver/chipset makers (FDTI), even gives instructions on how to 
"spoof" the driver into believing that you have the device it was 
shipped for. Unfortunately, the Cypress chipset is not even close. [If 
anyone knows of a Cypress serial driver PLEASE let me know!)

Until I can locate an OS X serial driver for the Cypress Semiconductor 
USB chipset (has to be for the low-speed, "HID" chips, which is what 
the Delorme Earthmate uses), I can't get Kismac (or any other software, 
like MAPe or TrueNav) to see it. The alternative, I suppose, would be 
for someone to figure out how to talk to the GPS as a native USB 
device. The TrueNav person I corresponded with seemed interested in 
that possibility, but I don't think it will happen any time soon. (Are 
the Kismac developers interested in doing this?)

The USB GPS that *does* have Mac OS X serial drivers -- but I haven't 
tested it -- is the TripNav TN200 from Rayming. If you go to the bottom 
of the product page you can find a link to the Mac drivers on the FDTI 

The Rayming server doesn't seem to be responding, but here's a retailer 
with the product:


Here's the FTDI page:



Richard Smith, Associate Professor School of Communication
Director, Centre for Policy Research on Science and Technology
Simon Fraser University, 515 West Hastings Street, Vancouver, CANADA
Phone: 604 291 5116 Web: http://www.sfu.ca/~smith/

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