How CMOS Works: MOSFETs, JFETs, IGFETS And More

CMOS opened the door for many if not most of the properties needed for today’s highly integrated circuits and low power portable and mobile devices. This really couldn’t happen until the speeds and current drive capabilities of CMOS caught up to the other technologies, but catch up they did.

Nowadays CMOS Small Scale Integration (SSI) logic families, I.E. the gates used in external logic, offer very fast speeds and high current drive capability as well as supporting the low voltages found in modern designs. Likewise the Very Large Scale Integration (VLSI) designs, or Very Very Large Scale if you like counting the letter V when talking, are possible due to low power dissipation as well as other factors.

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The Right Way To Do A Hacker Conference

DEFCON is huge. Last year attendance tipped at about 16k, and we’d wager this year will be even bigger. [Brian] and I will both be among those attending (more on that below) but I wanted to take this time to show you the right way to do a Hacker Conference.

Build Your Own Badge

We met a ton of people at DEFCON 22 last year, but the Whiskey Pirates made a lasting impression. I first ran across two of their crew walking the hallways of the con with this awesome badge. How can you not stop and strike up a conversation about that? Turns out this group of friends have been meeting up here for years. This year they went all out, designing one badge to rule them all. And like any good hacker project, they weren’t able to finish it before getting to the hotel.

Set Up Your Electronics Lab

So, you didn’t stuff your boards before leaving home? For the Whiskey Pirates this is not even remotely a problem. They just brought the electronics lab to their suite in the Rio Hotel.

On the bathroom vanity you find the binocular microscope which was good for troubleshooting an LED swap on the official conference badge. An entire cart with hot-air, multiple solder stations, oscilloscopes, and more was on hand. I populated the surface mount LEDs on the badge the crew gave to me. When I was having trouble seeing my work they called the front desk for an additional lamp. You should have seen the look on the bellhop’s face when he walked in!

A bit of marathon assembly and everyone from the Whiskey Pirates (plus me) had a working badge, demonstrated in the video below. But this isn’t where the fun stops.

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Hacking The Digital And Social System

When you live in a totalitarian, controlled and “happy” society, and you want to be a hacker, you have to hack the social system first. Being just an engineer doesn’t cut it, you have to be a hypocrite, dissident and a smuggler at the same time. That’s the motto of my personal story, which starts in Yugoslavia, and ends in Serbia. No, I didn’t move, I’m still in Belgrade, only the political borders have changed.

Half a century ago, when I was in elementary school, I discovered the magical world of HAM radio. I became a member of two amateur radio clubs, passed all exams and got my licence and callsign, which was YU1OPC. I was delighted, but after five years, the party was over. What happened? Well, one day the police paid a visit to all registered owners of CB Band equipment and simply took that equipment away. No one knows why they did it, but it was probably off the books, as we never got any written confirmation, and no one ever saw their equipment again.

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Virtual Physical Rehab With Kinect

Web sites have figured out that “gamifying” things increases participation. For example, you’ve probably boosted your postings on a forum just to get a senior contributor badge (that isn’t even really a badge, but a picture of one). Now [Yash Soni] has brought the same idea to physical therapy.

[Yash]’s father had to go through boring physical therapy to treat a slipped disk, and it prompted him into developing KinectoTherapy which aims to make therapy more like a video game. They claim it can be used to help many types of patients ranging from stroke victims to those with cerebral palsy.

Patients can see their onscreen avatar duplicate their motions and can provide audio and visual feedback when the player makes a move correctly or incorrectly. Statistical data is also available to the patient’s health care professionals.

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How To Rescue Your Quadcopter From A Tree

Whether it’s a new rocket, your latest quadcopter, or [Charlie Brown]’s kite, it always seems like there’s a tree waiting to catch and eat airborne projects. Sometimes you get lucky and find a way to climb up the tree to retrieve your wayward build, but most times you’re reduced to looking for rocks or sticks to fling up there in an attempt to shake it loose. But if you want to improve your chances of getting your stuff back, [U.S. Water Rockets] has a build for a retrieval tool made mostly from scrap bin parts that will help.

All you need is some PVC tubing, an old fishing reel and line, some latex surgical tubing, and a few dowels for projectiles. You can tell everything about the build from the BOM and stills, but the video after the break gives detailed instructions and shows it in action. Adding some fins to the dart or even substituting a cheap arrow from the sporting goods department of your favorite retailer might help with your aim. Even without fletching, the accuracy of the launcher is pretty good, and the range isn’t half bad either. Once the fishing line is over the branch that ate your quad it can be used to haul up successively stouter ropes, and pretty soon you’ll be shaking the tree like a boss.

Even if getting stuff out of trees isn’t on your immediate to-do list, this little hack could be put to other uses. Hams will use it to loft antennas up into trees, and tag-line placement for tree removal could be simplified with this tool. But if you still find yourself needing to retrieve stuff, you might want to be proactive and make your aerial robot tree-proof. That still won’t eliminate the need for drone-on-drone rooftop rescues.

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Hackaday Prize Entry: The Internet Of Plants

The theme of this year’s Hackaday Prize is ‘build something that matters.’ Acrobotic Industries is in beautiful Southern California, where it won’t rain an appreciable amount until the mudslides come. For a little bit of help during this unprecedented drought, they’ve created Clouden, a system of irrigation that only waters yards and parks when the plants need it. This is apparently a novel concept for Southern California, and is most certainly something that matters.

The Clouden system has two parts. The first is a node with an array of soil water sensors and a Particle WiFi module. This node connects to the controller which alters watering schedules in response to actual conditions and predicted rainfall from the WeatherUnderground API.

There’s more to just listening to sensors – the Clouden controller also has the hardware to control 24VAC water valves and a web interface for scheduling irrigation times. With this many sensors – and the ability to not water when there’s a ban in place – it’s a great watering system, and something Southern California desperately needs.

The 2015 Hackaday Prize is sponsored by:

Saving An Alarm System Remote And $100

[Simon] has been using his home alarm system for over six years now. The system originally came with a small RF remote control, but after years of use and abuse it was finally falling apart. After searching for replacement parts online, he found that his alarm system is the “old” model and remotes are no longer available for purchase. The new system had similar RF remotes, but supposedly they were not compatible. He decided to dig in and fix his remote himself.

He cracked open the remote’s case and found an 8-pin chip labeled HCS300. This chip handles all of the remote’s functions, including reading the buttons, flashing the LED, and providing encoded output to the 433MHz transmitter. The HCS300 also uses KeeLoq technology to protect the data transmission with a rolling code. [Simon] did some research online and found the thew new alarm system’s remotes also use the same KeeLoq technology. On a hunch, he went ahead and ordered two of the newer model remotes.

He tried pairing them up with his receiver but of course it couldn’t be that simple. After opening up the new remote he found that it also used the HCS300 chip. That was a good sign. The manufacturer states that each remote is programmed with a secret 64-bit manufacturer’s code. This acts as the encryption key, so [Simon] would have to somehow crack the key on his original chip and re-program the new chip with the old key. Or he could take the simpler path and swap chips.

A hot air gun made short work of the de-soldering and soon enough the chips were in place. Unfortunately, the chips have different pinouts, so [Simon] had to cut a few traces and fix them with jumper wire. With the case back together and the buttons in place, he gave it a test. It worked. Who needs to upgrade their entire alarm system when you can just hack the remote?