Hollow State Receiver

[Netzener] received a Radio Shack P-Box one tube receiver as a gift. However, at the time, his construction skills were not up to the task and he never completed the project. Years later, he did complete a version of it with a few modern parts substitutions. The radio worked, but he was disappointed in its performance. Turns out, the original Radio Shack kit didn’t work so well, either. So [Netzener] did a redesign using some some old books from the 1920’s. The resulting radio–using parts you can easily buy today–works much better than the original design.

The most expensive part of the build was a 22.5V battery, which cost about $25. However, you can get away with using three 9V batteries in series if you want to save some money. The battery provides the plate voltage for the 1T4 vacuum tube. A more conventional AA battery drives the tube’s filament. Continue reading “Hollow State Receiver”

Primes In A Box

Lots of useful things come in boxes. Shoes, soldering irons and… prime numbers? This simple project from [WhiskyTangoHotel] puts a list of prime numbers in a handy box. Press a button, get a prime.

Sure, it isn’t brain surgery: all that it is happening is that a Raspberry Pi is reading a number from a text file, then showing it on an LCD screen. But it’s well-documented project that shows how to tie together a number of things on the Pi, like writing to an I2C display and using a button to trigger a clean shutdown.

It might be a good starting project for the younger hacker or if you have a Pi pining for something to do. If you’re looking for more easy Raspberry Pi projects, check out our Enlightened Pi Contest.

Neopixels Light the Way in Pressure-Sensitive Floor

It’s got a little “Saturday Night Fever” vibe to it, but this pressure-sensitive LED floor was made for gaming, not for dancing.

Either way, [creed_bratton_]’s build looks pretty good. The floor is a 5×6 grid of thick HDPE cutting boards raised up on a 2×4 lumber frame. Each cell has a Neopixel ring and a single force-sensitive resistor to detect pressure on the pad. Two 16-channel multiplexers were needed to consolidate the inputs for the Arduino that’s running the show, and a whole bunch of wall warts power everything. The video below shows a little of the build and a look under the tiles. It’s not clear exactly what game this floor is for, but you can easily imagine a maze or some other puzzle that needs to be solved with footsteps.

Light-up floors are nothing new here, what with this swimming pool dance floor. But this interactive dance floor comes close to the gaming aspect of [creed_bratton_]’s build.

Continue reading “Neopixels Light the Way in Pressure-Sensitive Floor”

Orange Pi Releases Two Boards

A few years ago, someone figured out small, cheap ARM Linux boards are really, really useful, extremely popular, sell very well, blink LEDs, and are able to open the doors of engineering and computer science to everyone. There is one giant manufacturer of these cheap ARM Linux boards whose mere mention guarantees us a few thousand extra clicks on this article. There are other manufacturers of these boards, though, and there is no benevolent monopoly; the smaller manufacturers of these boards should bring new features and better specs to the ARM Linux board ecosystem. A drop of water in a tide that lifts all boats. Something like that.

This week, Orange Pi, not the largest manufacturer of these small ARM Linux boards, has released two new boards. The Orange Pi Zero is an inexpensive, quad-core ARM Cortex A7 Linux board with 256 MB or 512 MB of RAM. The Orange Pi PC 2 is the slightly pricier quad-core ARM Cortex-A53 board with 1 GB of RAM and a layout that can only be described as cattywampus. We all know where the inspiration for these boards came from. The price for these boards, less shipping, is $6.99 USD and $19.98 USD, respectively.

The Orange Pi Zero uses the Allwinner H2 SoC, and courageously does not use the standard 40-pin header of another very popular line of single board computers, although the 26-pin bank of pins is compatible with the first version of the board you’re thinking about. Also on board the Orange Pi Zero is WiFi provided by an XR819 chipset, Ethernet, a Mali400MP2 GPU, USB 2.0, a microSD card slot, and a pin header for headphones, mic, TV out, and two more USB ports.

The significantly more powerful Orange Pi PC 2 sports a quad-core ARM Cortex-A53 SoC coupled to 1 GB of RAM. USB OTG, a trio of USB 2.0 ports, Ethernet, camera interface, and HDMI round out the rest of the board.

Both of Orange Pi’s recent offerings are Allwinner boards. This family of SoCs have famously terrible support in Linux, and the last Allwinner Cortex-A53, that we couldn’t really review, was terrible. Although the Orange Pi Zero and Orange Pi PC 2 are new boards and surely software is still being written, history indicates the patches written for this SoC will not be sent upstream, and these boards will be frozen in time.

If you’re looking for a cheap Linux board with a WiFi chipset that might work, The Orange Pi Zero is very interesting. The Orange Pi PC 2 does have slightly impressive specs for the price. When you buy a single board, though, you’re buying into a community dedicated to improving Linux support on the board. From what I’ve seen, that support probably won’t be coming but I will be happy to be proven wrong.

Tiny Game Boy (That Plays Witcher 3) and Other Things That Blew My Mind

For years Sprite_TM has been my favorite hacker, and yet he continues to have an uncanny ability to blow my mind with the hacks that he pulls off even though I’m ready for it. This weekend at the Hackaday SuperConference he threw down an amazing talk on his tiny, scratch-built, full-operational Game Boy. He stole the badge hacking show with a Rick Roll, disassembled the crypto challenge in one hour by cutting right to the final answer, and managed to be everywhere at once. You’re a wizard Harry Sprite!

Here’s what’s crazy: these are the antics of just one person of hundreds who I found equally amazing at the conference. It feels impossible to convey to you the absolute sincerity I have when I say that SuperCon was far and away the best conference I’ve ever been to or have even heard about. It managed to outpace any hyperbole I constructed leading up to the weekend. This morning felt like I was waking up from a dream and desperately wanted to fall asleep again.

Continue reading “Tiny Game Boy (That Plays Witcher 3) and Other Things That Blew My Mind”

Fictional Hacking: Michael Westen

I don’t know if it is true or not today, but in fiction, spies depend on lots of high-tech gadgets. I do know that during World War II, the various secret services like the OSS and the SOE did have gadgets like secret transmitters and concealed weapons. But, like [James Bond’s] grenade-launching ink pen, to [Maxwell Smart’s] shoe phone, those gadgets came from some organized lab. (When you watch the video below, remember that at that time, a personal phone going off in a theater was unknown as cell phones were years in the future.)

Continue reading “Fictional Hacking: Michael Westen”

A Car Stand made of Sand

When the guys at [Practical Engineering] say they have a dirty car stand, they really mean it! They made a block of dirt and sheets of fiberglass as reinforcement material, and the resistance was put to test by using it as a car stand. And yes, the block does the job without collapsing.

An exmple of MSE
A MSE structure. The lateral walls add no strength, they just look nice.

Soil is a naturally unstable material, it relies only on friction for structural stability, but it has a very low shear strength (the resistance of the material’s internal structure to slide against itself). Therefore, as soon as you put some weight, a soil structure fails. The trick is to form a composite by adding layers of a stiff material. Those layers increase the shear strength and you end up with an incredibly strong composite, or ‘mechanically stabilized earth‘ (MSE). You probably drive by some everyday, as in the picture at the right.

Even though the modern form of MSE was due to French engineer Sir Henri Vidal, reinforced soil has been used since the beginnings of human history, in fact, some sections of the Great Wall of China were made using this technique. [Practical Engineering] explanation and demonstration video is very well made, be sure to check it after the break. In case you don’t want to play with dirt next time you need to fix your car, you can always make a 3D printed jack.