This hack is an interesting twist that will allow you to get in or out of some parking garages when the attendant isn't looking. Using something metal to trip the parking lot's proximity sensor that is meant to let cars out automatically you can get into the garage or vice-versa without opening your wallet. A magnet from a hard drive might work a bit better because it is able to trip multiple types of sensors, but for this hack any kind of metal will work. This proximity sensor is a high–frequency oscillation type, so anything that attenuates, varies the frequency or stops the oscillation trips the sensor. When you can't find a place to park, this hack will certainly impress your friends more than this method, but your street credibility could quickly turn into never lived down stories, if you end up driving over tire strips and ruining your tires, get a huge parking or trespassing ticket, or worse yet get your vehicle towed!
Free parking garage access
This hack is an interesting twist that will allow you to get in or out of some parking garages when the attendant isn't looking. Using something metal to trip the parking lot's proximity sensor that is meant to let cars out automatically you can get into the garage or vice-versa without opening your wallet. A magnet from a hard drive might work a bit better because it is able to trip multiple types of sensors, but for this hack any kind of metal will work. This proximity sensor is a high–frequency oscillation type, so anything that attenuates, varies the frequency or stops the oscillation trips the sensor. When you can't find a place to park, this hack will certainly impress your friends more than this method, but your street credibility could quickly turn into never lived down stories, if you end up driving over tire strips and ruining your tires, get a huge parking or trespassing ticket, or worse yet get your vehicle towed!
Electric screwdriver robot hand

Here's an interesting grabber hand built for use on an ROV. This grabber is a novel use of a very common and extremely cheap electric screwdriver, that is probably found in everyone's toolbox. It is also a great way to reuse that small electric screwdriver you have kicking around that uses proprietary batteries that are not worth replacing. Many of the ROV's covered previously could benefit from such a powerful device built from very common materials off his parts list. Because the screwdriver was extremely cheap the designer chose not to completely seal the housing.
It seems like this simple design that could be used in many robotic projects and by simply changing the jaws could yield other creative uses. The first thing that comes to mind is to upsize this hack into something bigger and stronger. Either way, you might not want to get your fingers in there.
How-To: Etch a single sided PCB
Making a PCB is very simple; it does not consume a lot of time and the results look professional. After reading this How-To and watching the step by step video, you will be able to make your own PCB in your workshop using just a few inexpensive materials.
Many people use protoboard and point-to-point wire everything, but needing multiple copies of the same circuit is the reason that forces many away from using protoboard. After making your first circuit board, you might not point-to-point wire anything again!
How-To: Go green with lead free solder

We covered many of [Jason Rollette]'s personal projects in the past and are happy to welcome him as our newest Hack-A-Day contributor.
The electronics industry has shifted to lead free compliance, but most hobbyists haven't even considered the personal impact of using lead. Today's How-To will cover what it takes to switch from tin/lead solder to completely lead free. Our previous posts Introduction to soldering and the follow-up still apply to lead free. You may have never considered switching to lead free before, but we hope to help you make an informed decision.

