Now You Can Record Mermaids Singing

Buy stock in hot glue, this project corners the market on the stuff. [Leafcutter John] uses the hot goop as his water-proofer of choice when building an underwater microphone (also known as a hydrophone). By installing a couple of piezo elements on one lid of a tin can he is able to record some amazingly clear audio. This is aided by a pre-amp inside the metal enclosure. By cleaning off the clear coating from the inside of these steel can parts, he was able to solder the seams to keep the water out.  In the end, coins are added for ballast and any remaining space is completely filled with hot glue.

He’s got a handful of example recordings on his project page. Here’s an what a running faucet sounds like from under water:

Hacking The OnStar GPS V2

[Andy] has provided us with his new guide to hacking the OnStar GPS. Previously, we have covered a way to grab the GPS data from an unused OnStar system, however in recent years GM has added much more complex systems, which make it harder than swapping out a serial line. For the new version, [Andy] has figured out GM’s Controller Area Network (CAN), which they call GMLAN. He has also done most of the software snooping and sleuthing, and has mostly solved GMLAN’s method of announcing GPS data. There is sample code available to convert this information into generic latitude and longitude.

Unfortunately for the project, (and very fortunately for [Andy]), he has a child on the way and new job responsibilities, so he is offering up his results to the HaD community to finish up, double check, and provide a good how-to for everyone else. To anyone who decides to pick up this project and run with it, let us know!