Crank-arm Style Hexapod

The latest robot out of Nolebotic is Al.I.S.E, or Aluminum, Infrared Scanning Entity. Don’t let the name fool you, its a pretty simple take on the classic hexapod walking platform using a crank arm and leavers made into the legs.

The body of the robot is made out of aluminum which is pretty easy to work with at home, lightweight, and sturdy. Bolted to the body are a pair of beefy gear head motors, a 9.6 volt rechargeable battery pack, along with a basic stamp 2 and its own 9 volt supply, and a Solarbotics 1198 CMD driver board.

Obstacles are handled right now with rudimentary infrared detectors and emitters, but it seems to work pretty good avoiding some library books in the demo. Combine that with clean mechanics and a pretty good stride and this thing can get up and move pretty quick.

Quick and easy DIY kegerator

diy_kegerator

I think we can all agree, there are few things that go better with hacking everything than beer. [Tom] has taken his love for beer and building things, fusing them together in a DIY kegerator. Using an off the shelf mini fridge and some easy to find beer serving components, he walks us through the conversion step by step. When everything is said and done, the kegerator should hold two 5-gallon kegs along with the CO2 tank required to serve the beer.

The process is admittedly pretty easy, but it’s probably the quickest way to go from zero to kegerator. [Tom] has this down to a science, knowing exactly what needs to be altered and removed, so following his tutorial should save you time and headaches, should you attempt this conversion yourself.

It would be great to see this project expanded to include precision temperature controls, a method of determining how much beer remains in the kegs.

Santa-pede contest winners

We received several fantastic entries. We laughed, we cried, we stared at our monitors in confusion, it was fantastic. Now we’re here to announce the winners of the Santa-Pede contest.

If you recall, the rules were pretty simple. Aquire a dancing santa (or other holiday dancing annoying toy thingy in the same fashion), tear it apart, build something that walks out of the pieces. We were aware that most of these have a very similar setup with one or two servos and a bit of plastic. That way everyone has a similar starting point.  We were amazed at what was done with so little.

Keep reading to find out who one each of the three categories: Most over-done,  best walker with no extra parts, and best presentation.

[Read more...]

A trio of last-minute 555 timer projects

555_timer_secret_knock_circuit.jpg

[Bob] has been busy lately putting the finishing touches on three different projects that he plans on entering into the 555 Design Contest.

His first entry is a low-power H-bridge, which can be used to drive small servos. While he admits that it is a bit odd to build use a 555 timer to construct an H-bridge, they are cheap and plentiful enough to justify their use. Check out the video below to see the simple H-bridge controlling a servo.

[Bob's] second entry is quite a bit more complex than his H-bridge. His secret knock detector listens for a pattern of knocks, triggering a relay if the proper cadence is detected. If a knock is heard, the first 555 timer starts, listening for another knock within a specific time range. If a knock is heard during this period, the next timer is triggered, and the process is repeated. Subsequent knocks must be timed correctly, or the circuit halts, waiting for a reset timer to expire before listening is resumed. It’s a bit hard to get the knocks just right, but that should be fixable with a few small tweaks.

The third entry he sent us is a project that is pretty common, though with a somewhat uncommon implementation. Class D amplifiers are often built as low-power headphone amps for personal audio applications. He liked the idea of a Class D amplifier, but wanted to build something with enough power to listen to his music in a small room. To accomplish this task, he looked over the internal block schematics of a 555 timer and constructed a pair of high-power 555 timers himself, using discrete components to mimic those usually found in the 555 package. His results were decent, though admittedly not of the highest quality, and could be tweaked a bit to provide better sound fidelity.

Continue reading to see videos of each project in action.

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Alien life form synth toy

space_bug_in_a_bottle

We were sent [Dr. Offset’s] most recent project, a kid’s toy that is half sculpture/half noisemaker, but 100% cool. The device uses several 555 Timers and is his entry into the 555 Design Contest, which wraps up in just a few days. To really enjoy his creation, you need to suspend disbelief for a moment, and indulge the space fantasy he creates. In other words, let yourself be a kid again, if only for a few minutes.

What he has built is a containment unit for an alien life form found during an outer space exploratory mission. The creature has fused its organic bits with electronic components in order to survive in the stark, empty world it used to call home. The containment unit allows you to zap the “bug” with various frequencies to see how it reacts. The “bug” is light sensitive, so it always offers a varying experience, day or night.

It’s definitely one of the most artistically creative entries into the 555 Design Contest we have seen yet. Continue reading to see a thorough walkthrough and demonstration of his project.

[Thanks Rich Decibels]

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2-bit full adder using just thirty six 555 timers

This 2-bit adder was a lot of work to build. It uses a total of thirty-six 555 timers and it does have the option of adding or subtracting numbers. It’s a rather unorthodox use of the part, depending more on the chip as an inverter and taking advantage of the fact that there’s an NPN transistor built into it. [cpu86] did use some PNP transistors to give him the ability to turn off some of the 555’s to get everything working correctly.

He explains the use of two’s complement in the subtracting feature but the process is just touched on very quickly. Luckily there’s a huge eagle schematic available with his project writeup so that you can follow along and really grasp how this thing works. We’ve generated a PNG and embedded it after the break for your convenience. You’ll find it just after the two videos of the device in action.

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Reverse engineering shopping cart security

All this talk about 555 timers is causing projects to pop out of the woodwork like this one that reverse engineers a shopping cart security mechanism. The wheel seen above listens for a particular magnetic signal and when encountered it locks down the yellow cowl, preventing the wheel from touching the ground and making the cart very hard to move.

[Nolan Blender] acquired one of these wheels for testing purposes and he’s posted some details about the hardware inside. But the first thing he did was to put together some test equipment to help find out details about the signal that trips the mechanism. He connected a coil to an audio amplifier and walked around the market looking for strong signals. Once he found a few strong bursts with that equipment he grabbed an oscilloscope, hooked it to the coil, and made some measurements. He found an 8 kHz signal at a 50% duty cycle at 30 ms intervals (it would be hard to make a better case for why you need an oscilloscope).

With the specs in hand, [Nolan] grabbed two 555 timers, an audio amplifier, and a 200 turn antenna around a ferrite core to build his own locking mechanism. If you’re ever stopped short in the middle of the market, just look for the hacker at the end of the aisle holding the homemade electronics.

[Photo source]

[Thanks Colin]

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