Mapping Hacks

Build Your Own Car Navigation System with GpsDrive #63

Chapter 5, Mapping with Gadgets

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289

HACK

advance. If you drive off of the current map, GpsDrive stops showing your

current position. So when I pulled up at a stoplight in San Francisco, I con-

nected to a random open wireless network and downloaded a map. I

repeated this pattern through most of the city: stop at a light, try to con-

nect, download one or two maps, and then pull away.

There is something strangely compelling about seeing your track as it picks

its way across a map that you just downloaded while stopped at a light.

Installing and Using GpsDrive

GpsDrive is available at: http://www.gpsdrive.de. Under Linux, download the

appropriate RPM and then type:

$ rpm -ivh gpsdrive-2.09.i386.rpm.

Of course, you can also compile from source code. Under FreeBSD, use the

ports collection:

$ cd /usr/ports/astro/gpsdrive

$ sudo make install; make clean

$ rehash

And then start GpsDrive:

$ gpsdrive

GpsDrive supports various GPS options. I connected a Garmin III plus to

the serial port on a machine running Fedora Core 2. In GpsDrive, click on

Preferences

➝ Settings 2. I set my GPS to communicate in NMEA mode, and

so I selected “Use serial conn” to directly talk to the serial port. I set the

serial port to /dev/ttyS1, and then used chmod to set the permissions on /dev/

ttyS1. NMEA talks at 4800 by default, so leave that alone.

Clicking “Download map” brings ...