Very fun article, not on GPS units ability to be GPS units, but about their lack of interest in playing nice with 3rd party software / drivers, and the very clever workarounds that can be done to overcome their shortsightedness. Read this article!

That's some righteous hacking... backing out the vendor from the packet checksum & header... :-)

Was in Boston a few weekends ago, and our (decent Garmin) GPS system would lose it's signal with about 200 feet to go in each tunnel, and then would take 1-2 minutes to reconfigure itself which was typically too late to help us make the right exit. It was frustrating to say the least to have to memorize the route 4-5 steps ahead each and every time we entered a tunnel just in case it got confused (which is did early and often)

Why can't the unit 'remember' the route in case signal is lost or have some sort of 'tunnel' recognition mode to account for this? It's not like the 'Big Dig' is an obscure set of tunnels (or Boston an uncommon city) that just 'popped up' without warning.

/rant

I was surprised at how well my Garmin Nuvi has been working in the Boston tunnels actually. It also tended to recover pretty quickly.

By the way, that isn't what the article is talking about. It's quite an interesting read about how NMEA screwed up the GPS protocol.

Some of the Garmin units come with a wire that hooks into your car that allows for "dead reckoning" by watching your speed and braking pattern, so it can keep up with you when you're going through an area with no reception.

My in-dash unit does this. It works great for tunnels and parking garages.

The problem I always have with my GPS system is that it sucks if you know where you are actually going.

For example if I skip a step to take an exit(because I find it faster by using the next one), it'll spend the rest of the way trying to reroute me to go back to the step that I skipped. So I can be pulling into my driveway, and the system will be trying to send me back 50 miles to take that exit that it wanted me to take.

Granted I have the cheap $150 system, since I barely use it, so maybe the more expensive systems are smarter

Indeed, my mom's 2004 lexus's builtin GPS will automatically recalc the route as you do whatever you want.

There are very few features to differentiate GPS systems. The chipsets themselves have become pretty good, and the good ones aren't terribly expensive. Instead vendors have to find other ways to do it. Inevitably that's going to be finding really irritating ways to make people want a higher-up model.

On another note, I really should get her a new maps DVD..

I had a top of the line Garmin model which quickly noticed when you ignored a direction, and re-calculated the route in less then a second.

Until it got stolen.

Well, at least it knows where it is.

Ah yeah - someone on the Internet designed a wrong interface.