Decoding the SpeedcamUpdates.spud file
 

I saw @PERRIN_Jeff's post on modifying the nav's startup screen and the "speedcam" folder and got curious. I was able to create a speed cam entry manually in the nav interface; it writes a "SpeedcamUpdates.spud" file to the SD card. But that's boring. It seemed like the kind of thing that should be hackable. And it is.

I found a post (partially) detailing the format of that file on the GpsPasSion forums. I'm fluent with Python, so I threw a little something together on GitHub. It's rough, only decoding the one point I put in (which isn't even a camera, it's a fixed "you're going too fast" sign). If you're into that sort of thing, you can play along, too!

Let me know what you think. :)

Is it possible to do this in reverse? Say you got a dump of speed camera locations from a place like http://www.poi-factory.com. Once you formatted them correctly, is it possible to create a new SpeedcamUpdates.spud that the nav unit will read?

Absolutely. I'll have to do a little more noodling to figure out what if anything changes in the header, but then it's just a matter of re-packing the source file into the binary "spud" format.

Seems that I heard that they're illegal in Massachusetts (yay!), but known speed traps could be used, too.

I'm curious as to what this functionality was even designed for. Insurance?

I guess you could call it that. With a list of speed cameras in the nav, it'll alert you when you're getting close to one (optionally only if you're speeding).

In some countries disclosure of speedcam locations is required by law. I think UK is one of them.

Being a global vehicle, they saved on one version of firmware for all regions. Apparently, US data is missing.

Keep up the good work! Simple py converter from poi-factory (e.g.csv) to spud format would be super useful! Make sure it runs on py 2.6.1 :)

I created a sample set of points last night with some combinations of the various types of alerts, directions, etc. I've now decoded most of the file (and found that the original format I found was only partly applicable), but there are still four bytes I don't know what to do with. They could be a checksum, or additional information that's not visible from the nav UI… Can't build a new file from scratch until that stuff can be decoded.

The GitHub project's been updated accordingly.

If that's true than a cop blatantly lied to me about being caught speeding on camera. I should've known he was bull$#!tting when I never got a ticket in the mail. I think he was just too lazy to run my license and reg, which was just as well!

Either way, this thread is very interesting! You could perhaps program known speed traps from here:

http://www.speedtrap.org/

I would love you forever.

According to this, tickets must be hand-delivered to the offender. Wow, that's like totally anti-nanny-state! Go Mass!

Yep. You're correct.

Any update on this?

Try using the waze app?

No. Haven't had time to work on it. If anyone else wanted to play with creating some sample files via the nav, however, that'd perhaps be helpful in figuring out what some of these mystery fields are.