Hacklet 73 – Parallax Propeller Projects

In 2006, Parallax, Inc wasn’t new to the electronics business. They’d been around since 1987. Still, for a relatively small company, jumping into custom chips is a big leap. Parallax didn’t just jump into some cookie cutter ASIC, they made their own parallel multi-core microcontroller. Designed by [Chip Gracey], the Parallax Propeller has 8 cores, called cogs. Cogs are connected to I/O pins and other resources by a hub. The Propeller saw commercial success, and continues to have a loyal following. This week’s Hacklet is about some of the best Propeller projects on Hackaday.io!

wozWe start with retrocomputing prop star [Jac Goudsmit] and L-Star: Minimal Propeller/6502 Computer. [Jac] loves the classic 6502 processor. Inspired by [Ben Heckendorn’s] recent Apple I build, [Jac] wanted to see if he could replicate an Apple I with minimal parts. He built upon the success of his Software-Defined 6502 Computer project and created L-Star. The whole thing fits on a Propeller proto board with room to spare. The project uses a 6502, with a Propeller handling just about everything else. The system takes input from a PS-2 keyboard, and outputs via composite video, just like the original Apple I. As you can see from the photo, it’s quite capable of displaying Woz in ASCII. [Jac] has expanded the L-Star to support the Ohio Scientific C1P and CompuKit UK101, both early 6502 based computers.


bbotNext up is [Mike H] with B-BOT. B-BOT is a balancing robot. [Mike] used B-BOT to learn about designing with the Propeller and programming in SPIN, the Prop’s built-in interpreted language. While slower than assembler, SPIN was plenty fast enough to solve the classic inverted pendulum problem. B-BOT’s primary sensor is a Pololu AltIMU-10. This module contains a gyro, accelerometer, compass, and altimeter all on one tiny board. Locomotion comes in the form of two stepper motors. Command and control is via X-Bee radio modules. All the parts live on a custom PCB [Mike] milled using his CNC router.


xynq[Antti.lukats] created Soft Propeller, his entry in the 2015 Hackaday Prize. Soft Propeller doesn’t use a hardware Propeller at all. The core of the system is a Xilinx Zynq-7 chip, which contains an FPGA and a Dual Core ARM A9+ processor. Back in 2014, Parallax released the Verilog HDL code for the Propeller core. [Antti] has taken this code and ported it over the Zynq-7. With 256Kb of RAM, 16 MB of Flash and an LED, the entire system fits in a DIP package smaller than a stick of gum.


pipmanFinally, we have [Christian] with Pipman GPS Watch. There’s just something about the Pip-boy from the Fallout video game series. This Personal Information Processor (PIP) has spawned hundreds of projects from cosplayers and electronics hobbyists alike. [Christian’s] version uses a 4D systems TFT LCD to display those awesome graphics. Input comes through a 5 way navigation switch. A GPS and compass module provide all the navigation data Pipman needs. At the center of it all is a Parallax Propeller programmed in SPIN. [Christian] has a working prototype on his bench. He’s now working on modeling a 3D printed case with Blender.

There are a ton of Propeller projects on Hackaday.io. If you want to see more, check out our Propeller Project list! Did I miss your project? Don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet, As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

The Making Of The Hackaday Prize Video

As you’re probably aware, there’s a video announcing the launch of The Hackaday Prize blocking the front page of Hackaday right now. This is by design, and surprisingly we haven’t gotten any complaints saying, ‘not a hack’ yet. I’m proud of you. Yes, all of you.

Making this video wasn’t easy. The initial plans for it were something along the lines of the new Star Wars trailer. Then we realized we could do something cooler. The idea still had Star Wars in it, but we were going for the classics, and not the prequels. As much as we love spending two hours watching a movie about trade disputes, we needed to go to Tatooine.

QV4A4035I just wanted to go to Toshi station

This meant building a prop. We decided on the moisture vaporators from Uncle Owen’s farm. It’s a simple enough structure to build at the Hackaspace in a weekend, and could be broken down relatively easily for transport to the shooting site. I’ve created a hackaday.io project for the actual build, but the basic idea is a few pieces of plywood, an iron pipe for the structural support, and some Coroplast and spray paint to make everything look like it’s been sitting underneath two suns for several decades.

Oh, I was the only person at the hackaspace that knew what greebles were. That’s not pertinent in any way, I’d just like to point that out.

The Suit

The vaporator is the star of the show, but we also rented a space suit. No one expected teflon-covered beta cloth when we were calling up costume rental places, but the suit can really only be described as a space-suit shaped piece of clothing. The inlet and outlet ports are resin, and the backpack is a block of foam. If anyone knows where we can get an Orlan spacesuit, or even a NASA IVA or Air Force high altitude suit, let us know.


[Matt Berggren] led the prop build and starred in the assembly footage. [Aleksandar Braic] and [Rich Hogben] rented a ridiculous amount of camera equipment. On set for the hijinks was [Aleksandar “Bilke” Bilanovic], [Brian Benchoff] (me), [Jasmine Bracket], [Sophi Kravitz], and [Mike Szczys].

Retrotechtacular: The Construction of Wooden Propellers

During World War I, the United States felt they were lagging behind Europe in terms of airplane technology. Not to be outdone, Congress created the National Advisory Committee for Aeronautics [NACA]. They needed to have some very large propellers built for wind tunnel testing. Well, they had no bids, so they set up shop and trained men to build the propellers themselves in a fantastic display of coordination and teamwork. This week’s film is a silent journey into [NACA]’s all-human assembly line process for creating these propellers.

Each blade starts with edge-grained Sitka spruce boards that are carefully planed to some top-secret exact thickness. Several boards are glued together on their long edges and dried to about 7% moisture content in the span of five or so days. Once dry, the propeller contours are penciled on from a template and cut out with a band saw.

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3D printed arc reactor replica


[James] just keeps cranking on the idea of the perfect arc reactor replica. This time around he’s made most of the parts using a 3D printer. His write-up covers the basics of the build, but he also used this opportunity to make some tutorial videos on designing the parts using Autodesk 123D.

This is definitely an improvement on his last prop, which was built out of dollar store parts. When designing the components he tried to be as true to the original movie design as possible, while keeping in mind the limitations of using a home 3D printer; he printed them on a Lolzbot AO-101.

The videos below give you a good idea of what it’s like to model parts using 123D. The tool set is pretty simple compared to something like Blender 3D. But [James] uses them in such a way that the components get complex fairly quickly. The second video includes some footage of the parts being printed, as well as the assembly process that adds wrapped wire for looks, and LEDs for illumination.

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Building Han Solo’s blaster



It’s no secret that [Adam Savage] of Mythbusters fame is a huge fan of replica props, going so far as to make a Maltese Falcon out of Sculpey. This time, though, he’s doing one better for the nerds in the crowd by building the most accurate replica of Han Solo’s blaster ever.

Replica prop gurus already know [Lucas]’ original prop department based Han Solo’s BlasTech DL-44 blaster off an existing gun – the Mauser C96. Along with this gun, there were a few extra bits and bobs tacked onto this gun, including an old German scope, a flash hider from an aircraft machine gun, and even a few bits of metal from a model airplane.

All these extra parts and greeblies are very hard, if not impossible to find. Thankfully, there are a bunch of very skilled replica prop makers reproducing these parts for anyone who wants a very accurate DL-44 Blaster. [Norm] from Tested and [Adam] assembled these parts into an incredibly accurate replica of the ‘hero’ blaster – by far the most identifiable of Solo’s many iterations of blaster seen in Star Wars ep. IV.

Beautiful replica Team Fortress 2 weapons


We’ve seen our share of replica props, but [Nathan]’s replica of the spy’s sidearm from Team Fortress 2 is the bee’s knees.

The build began as an off-the-shelf Airsoft gun. After removing the barrel and cylinder, [Nathan] used Apoxie Sculpt and a whole lot of sanding to turn a stock piece of metal and plastic into something that came straight from the Mann Co. store. The in-game version of the Ambassador also includes an engraving of the object of the spy’s affection, replicated by [Nathan] with some very careful Dremel work. Once the prop was done, [Nathan] built a mold box out of plywood and filled it with silicone rubber. This allowed him to make several castings of his prop weapon

This isn’t [Nathan]’s only TF2 replica prop; he also made a replica of the stock sniper gun and scout’s scattergun and a megaphone from Borderlands. In an effort to out do himself, [Nathan] is gearing to build a gun that fires two hundred-dollar, custom-tooled cartridges at ten thousand rounds per minute. He has yet to craft any hats.

A wearable Pipboy 3000

[Zachariah Perry] builds a lot of replica props, and judging from the first few offerings on his blog he’s quite good at it. We enjoyed looking in on the Captain America shield and Zelda treasure chest (complete with music, lights, and floating heart container). But his most recent offering is the wearable and (kind of) working Pipboy 3000 from the Fallout series.

From his description in the video after the break it sounds like the case itself came as a promotional item that was part of a special edition of the game. He’s done a lot to make it functional though. The first thing to notice is the screen. It’s domed like the surface of a CRT, but there’s obviously not enough room for that kind of thing. The dome is made from the lens taken out of a slide viewer. It sits atop the screen of a digital picture frame. [Zachariah] loaded still images from the game into the frame’s memory, routing its buttons to those on the Pipboy. He also added a 12 position rotary switch which toggles between the lights at the bottom of the screen.

A little over a year ago we saw a more or less fully functional Pipboy. But that included so many added parts it was no longer wearable.

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