Update 7-13-11: I’ve posted an updated set of instructions on getting GPSd to compile on OS X here; this post will remain for archival purposes. For information on installing GPSDrive, see this post.

So I recently picked up a cheap GPS module on Amazon. It was about $30 with shipping, and I got a neat little dongle which connects over USB to my computer and communicates with software. It didn’t come with support for OS X (although interestingly enough it shipped with Mac OS 8 and 9 drivers), but it promised to send generic NMEA-0183, so I wasn’t too worried.

When it showed up, some quick software probing revealed that it houses a usb to serial adaptor (a Prolific PL-2303, which I’ll get to in a bit) and a gps module that’s configured to send NMEA strings through the virtual serial port. This sort of information is compatible with a host of software, but most of it is commericial, and only available at a considerable price.

Luckily, there’s a wonderful open source project called gpsd which provides support for a wide raft of devices and protocols, and talks to an even wider assortment of software. Primarily, I wanted to be able to get my gps to talk to the network scanner Kismac, and Randall Munroe’s cyborg.py script. Both of these were built to take information from gpsd, so I was in business. However, gpsd, which is designed to play nicely with Linux, takes some coaxing under OS X. This is meant to describe how I got it all running. Continue reading →