[Scott] Made A Single-chip Hellschreiber On Earth

August 8, 2011 by Mike Szczys 38 Comments

[Scott Harden] is drilling teeth by day and designing radios that send secret messages by night. He’s set his sights on the Hellschreiber protocol which was used by the Germans in World War II along with their Enigma encryption system. The protocol is a viable alternative for transmitting and receiving code in environments with too much background noise for other communication systems.

His goal was to develop his own transmitter using just one microcontroller. He picked an ATmega48 and coupled it with a 40 MHz crystal oscillator. [Scott] mentions that there is no other hardware necessary, but static messages stored in an array so you’d need some other hardware to push your own characters through via the chip’s UART or otherwise. The AVR sends messages by converting the data into audio using PWM. That signal is fed into the crystal oscillator, which produces an amplitude modulated signal (AM) that can then be transmitted.

Check out his video after the break for a demonstration. He’s decoding the transmitted data using a free program called Ham Radio Deluxe.

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Noise Generator Ported To Run On Small AVR, Also Arduino Compatible

August 8, 2011 by Mike Szczys 12 Comments

Feeling a bit left out because he didn’t have a PICAXE on hand, [Rob Miles] decided to port the Luna Mod code so that it would work on an AVR chip. He chose to build his around an ATtiny45, but also mentions that this is Arduino compatible.

This case layout is a bit different from the original Make version, but we like this look just a bit better. It might not satisfy your need for that hipster looking enclosure, but the repurposed macadamia nut box looks seems it was built for this purpose. Take a look as the video after the break to see the final product and hear it spewing newly composed cacophony. [Rob] is sharing the sketch as a dropbox file but we’ve also included our own hosted link after the break in case is stops working.

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Portable Gets A Proper Home In An Arcade Controller

August 7, 2011 by Mike Szczys 16 Comments

[Luke] wanted an arcade-style controller that he could use for some gaming at home. He decided to use a portable game emulator as a base and then added his own joystick and buttons along with a custom case.

The donor hardware is a Dingo A320. It’s a nice little handheld with a 2.8″ screen, and plenty of potential to emulate games like Donkey Kong seen above, or to play homebrew. It’s even been the target of some RAM upgrades we looked in on in the past. The best part for [Luke’s] project is that it includes a video out port.

In the clip after the break you can see that [Luke] now has a compact controller with a huge arcade joystick, four buttons on the top surface, and the rest of the controls all around the edges of the enclosure. The video out option is selected in the menu system, so he preserved the original LCD for use during configuration.

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Most Useless Machine Upgrade — Now With A Button!

August 7, 2011 by Mike Szczys 11 Comments

There’s a soft spot in our hearts for pointless projects, as long as they’re well executed. [Bertho] really hit the mark with his take on the most useless machine. We’ve seen several renditions of this concept, most of them hinging on a box that will turn a mechanical switch off whenever you turn it on. But this take uses a push button to activate a switch flipping mechanism on another part of the machine.

You can see the drive gears in the image above. The final gear has a small bar which flips a switch to one side or the other. The circuit does this without the need of a microcontroller. A 7400 series NAND gate chip, some passive components, and two mechanical relays are all it takes. At each push of the button, the logic chip trips one of the relays to trigger the appropriate motor direction based on the current state of that switch. You can press the button during movement, but all that will do is delay the inevitable flip of the switch.

RC Car Hack Saves Lives In War Zone

August 7, 2011 by Mike Szczys 59 Comments

R.I.P sand-colored radio-controlled truck. Your life ended with a bang and in doing so, saved some lives. This little work-horse is a hack that [Ernie Fessenden] put together and sent to his brother [Sergeant Chris Fessenden] who is on a tour of duty in Afghanistan.

[Chris’] team is trained to be on the lookout for roadside bombs, but [Ernie] wanted to sent him something cool that could also keep him safe. By adding a camera to the hood of the Traxxis Stampede and using a gun-mountable LCD screen, the soldiers now have a way to see what’s on the road ahead from their armored Humvee. Sounds like it would work just fine right? Well the hack just got a big endorsement when it tripped an IED made of around 500 pounds of explosives. [Chris] and five other soldiers on patrol were unharmed in the event, and [Ernie] already has a replacement model on the way.

[Thanks Rioexxo and Alex]

More proof that battlefield hacks deserve a place next to some of the high-ticket items you’d usually associate with weapons of war.

Dead-bug Arduino Is Still Breadboard Ready

August 6, 2011 by Mike Szczys 28 Comments

Here’s a no-PCB Arduino that doesn’t obscure the DIP footprint of the AVR chip. It’s built on an ATmega88 chip, and includes a programming header, reset button, a couple of filtering caps, and an LED. This is modeled after the Lilypad hardware, and fits nicely on top of the plastic case of the microcontroller, allowing it to be used in a breadboard or DIP socket. You can see a walk through of the components in the clip after the break.

We don’t really need most of the components on top of the chip (especially the status LED on the SCK line), but there are several things that we like about this. First off, the programming header is extremely nice. We could see this coming in handy for prototyping where you don’t want to add a header to your final design. Just use a chip socket, and this chip while you’re developing firmware. Once everything is dialed in, program a naked chip and swap the two. The same goes for the reset button, which is nice when working on firmware but may not be necessary in your final design.

This is quite an old project, and we’ve actually seen a successor to it. This is Rev. 2 and we looked in on Rev. 7 back in March. That one is a full Arduino, but the circuit board has no substrate.

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RepRap Voyeurism

August 3, 2011 by Mike Szczys 13 Comments

Hey everybody, [Nbitwonder] is building his own RepRap 3D printer. What’s special about that? Well, not much and and lot all at the same time. The art of building a self-replicating 3d printer still has a lot to do with luck and forum-crawling to make all of the decisions that go into this complicated project.

Back in March [Nbitwonder] did a collaborative project over at Thingiverse and scored himself a set of printed parts from a guy who already has one of these printers. He then order a set of the non-printable hardware and has since been assembling it. If you’re interested but haven’t already taken the plunge, there’s enough pictures and information in this set of posts to satisfy your craving… for now.

We say this build is an art because it goes beyond just plunking the pieces together. Take the print head, for instance. Instead of going with the extruder that is considered the default for a Mendel build, [Nbitwonder] is working on a variation called Greg’s Hinged Accessible Extruder. We can’t wait until the hardware assembly is done, because it’s the calibration that really interests us.