Hot Hacks, Mods & Circuitry Posts

How To: Build a Cheap Arduino Tachometer to Measure the RPMs of Spinning Fans (And More)

A tachometer, or RPM counter, is a device that measures the speed of something that's rotating. In a car with a manual transmission, the tachometer can be helpful in determining when to release the clutch and how much gas to give when you're taking off. This DIY Arduino Tachometer by Chris on PyroElectro uses an infrared transmitter and receiver break-beam pair to measure the RPM of a computer fan. When the fan blade passes between the transmitter and receiver, the IR beam counts the interrup...

How To: Disguise Your Gaming Addiction with This DIY Coffee Table Arcade Machine

Love old-school games like Pac-Man and Space Invaders, but don't have the extra space for an arcade machine? Get the best of both worlds (and save some cash) with this DIY Arcade Coffee Table built by Sam Wang. He started with just an ordinary IKEA table and drawers, then cut out a space for an LCD monitor. The controls (including joysticks!) are mounted on the drawers so that when they close, it just looks like a normal coffee table. Once everything was in place, he added a glass table top, ...

DIY Portable Power Pack: Turn Your Backpack into a Solar-Powered Gadget Charger

A smartphone is pretty much useless with a dead battery. When you're out and about, it can be hard to find a place to plug in (if you remembered your charger, that is). But this DIY solar panel backpack made by electrical engineer Theodore Protasiewicz will help you use the scorching sun to your advantage and make sure that your gadgets are always ready to go. Theodore started with just a normal backpack, some solar panels, 18 gauge wire, and a USB port and hacked it into a traveling solar ch...

News: Artist Uses 300 Apples to Power 30 LEDs for 1 Electrified Fruit Battery Science Experiment

You've probably seen the classic fruit battery science experiment a thousand times, but I doubt you've ever seen it turned into an art project! Photographer Caleb Charland uses everyday objects like apples, coins and vinegar to create makeshift batteries, then takes these gorgeous long exposure photos. For the apple tree photo, Charland got about 5 volts for every 10 apples, so he had to wire 300 apples to power the lamp for several hours. He used a zinc-coated galvanized nail and copper wire...

How To: Geekify Your Business Card with This Custom PCB Résumé Flash Drive

Whether you're job searching, networking, or just giving your information out to someone you just met at a bar, this circuit board business card made by Brian Carrigan will make sure no one ever forgets meeting you! Sure, you could buy a customized USB business card on some online shop, but if you're trying to emphasize your geek cred, why wouldn't you make your own PCB card from scratch? Carrigan used a USB controller and added an Atmel AT45DB series flash chip so that it could store his res...

How To: This DIY Baby Monitor Uses Lasers and a Wiimote to Detect Your Child's Breathing

Proud new papa Gjoci wanted to make sure he never had to worry about whether or not his baby girl was breathing, so he built this amazing breath-detecting baby monitor using a Wii remote, a printed circuit, and a laser. First, he opened up the Wiimote and took out the camera, then used an Atmel Atmega88 microcontroller to make a printed circuit. Low-power infrared lasers shine on the baby's clothing and the Wii camera detects the motion of the baby's breath, activating an alarm if the motion ...

How To: Ditch Your Doorbell for This Front Door RFID Lock That Lets Whoever You Want In (Whenever You Want)

Hate answering the door, but don't trust your friends with a set of keys? This RFID front door lock made by Steve Pomeroy will solve all your party-hosting problems. It reads the RFID tags in his friends' public transit cards and decides who's allowed in based on "groups" that Steve defines. And I have to say, it's also rather stylish. It's controlled by an Arduino serial console and a custom Android app to add and remove cards. The reader can store 50 or 100 tags at a time and allows 7 diffe...

How To: Turn a Playing Card into a Super Simple Solar-Powered Battery Charger

You can do a lot more with playing cards than you'd think, like turn them into gift boxes, fling them like throwing stars, and make them levitate or disappear. You can even make them recharge your batteries. Instructables user Shawn Frayne was sick of having a bunch of dead batteries lying around, so he developed a cheap and easy way to always have a charged one within arm's reach by turning a normal playing card into a super simple solar-powered battery charger for rechargeable AA and AAA ba...

How To: Make Your Own Propane-Fueled Cotton Candy Machine at Home

Cotton candy is a treat generally reserved for carnivals, fairs, and other events that don't come around often enough. Through some clever construction and about $45 in materials though, you can have all the sugary substance you could ever want with this awesome DIY cotton candy machine. All you'll need to construct your own are two dollar store stainless steel bowls, a fan motor, a few odd screws and bolts, a drill, and a propane torch. Check out the tutorial video below. As an added bonus, ...

How To: DIY Pulsating Light Rod Speakers That Dance to Your Music

If you've found your speakers to be lacking in the visuals department, this is just the mod for you. Using 3" PVC, you can turn your speakers into light-up glow rods that pulse to the beat of your music. You'll need some electrical skills and experience soldering to get this one together, but otherwise it's not all that complicated. The main components you are going to need are speaker drivers, PVC pipes, LEDs, and the necessary cabling for those devices. The device works best with higher vol...

How To: Customize Your USB Keyboard with a DIY Illuminated Base with Built-In Phone Stand

I've never really liked to type on a flat or low keyboard. Even the small flip-up stands underneath most keyboards were not good enough for me, as those little legs aren't usually more than 2 or 3 centimeters high. I'd like a minimum of 5 cm, so I decided to make this keyboard base for myself. Aside from giving me the right height and angle, this DIY keyboard base also features LEDs that light up my monitor, the table, and gives a nice background to my desktop. It's even got a built-in stand ...

News: Unencrypted Air Traffic Communications Allow Hackers to Track & Possibly Redirect Flights

Considering how often many of us fly on commercial airlines, the idea that a hacker could somehow interfere with the plane is a very scary thought. It doesn't help to learn that at Defcon, a researcher found that the Automatic Dependent Surveillance Broadcast (ADS-B), transmissions that planes use to communicate with airport towers are both unencrypted and unauthenticated.

How To: Turn an Old Scanner into a Keyboard Light

Do-it-yourselfer Kipkay salvaged parts from an old parallel port scanner and made a flexible, super-bright light in this how-to video. The modification is done by extracting the lamp and running it through clear tubing. He mounted the new lamp above his keyboard for night typing. Watch this video tutorial and learn how to turn an old scanner into a keyboard light.

How To: Hack a toy radar gun into a real one

Turn a 'toy' radar gun into the real thing! Cops don't even have one like this! While this is a completely new and different design, the inspiration for this video is from an article by Ken Delahoussaye in MAKE Magazine. Just watch this video tutorial on how to hack a toy radar gun into a real one.

How To: Secretly record people with your own spy sunglasses

Hack a pair of sunglasses to secretly record audio and video and spend less than $40 in the process with this how-to video. To replicate this hack for yourself, you will need a spy camera and black solar shield sunglasses. For detailed, step-by-step instructions on building your own spy recorder sunglasses, watch this hacking how-to from Kip Kay of Make Magazine.

How To: Turn a flashlight into a laser

Kipkay demonstrates how to extract the laser from a DVD burner and mount it in a small flashlight to create a handheld laser burner that can light matches and burst balloons, all in this how-to video. All you need is a 16x DVD burner, a laser housing, and a flashlight. Watch this video tutorial and learn how to modify a flashlight into a relatively strong laser.

How To: Make a Blu-Ray Laser Phaser

Build your very own Trek-style Blu-Ray laser phaser with this hacker's how-to video from Kip Kay of Make Magazine. To replicate this hack at home, you'll need the following materials: (1) a PS3 Blu-Ray laser assembly (which can be had on eBay for roughly $45), (2) an original series-style Star Trek phaser gun (a good quality replica of which can be found for roughly $30), (3) a 9-volt battery, (4) a 9-volt battery snap, (5) a 150 Ohm resistor, and (5) a new switch to replace the phaser trigge...

How To: Make a motion triggered spy camera

Kip "Kipkay" Kedersha is known for his intriguing and clever how-to and prank videos, even when he teams up with MAKE Magazine. He will show you how to tweak, hack, mod, and bend any technology to your hacking needs. No electronic device, gadget, or household item can stand the test of Kipkay's hacks and mods.

How To: Make an infrared home alarm system

Kip "Kipkay" Kedersha is known for his intriguing and clever how-to and prank videos, even when he teams up with MAKE Magazine. He will show you how to tweak, hack, mod, and bend any technology to your hacking needs. No electronic device, gadget, or household item can stand the test of Kipkay's hacks and mods.

How To: Measure current, voltage, resistance, and continuity using a multimeter

If you own or have access to an auto-ranging or manual-ranging multimeter you can measure several different aspects of circuits, resistors, and the like. For example, you can determine the resistance, voltage, continuity, and current with the multimeter to help you determine the precision of a resistor. This guide will help you learn how to use a multimeter to perform these tasks.