Function Generator Gets DIY Frequency Standard

April 8, 2018 by Tom Nardi 5 Comments

For those of us who like to wrangle electrons from time to time, there are some exceptional deals out there for low (or at least lower) cost imported test equipment. If you’re willing to part with a few hundred dollars US, you can get some serious hardware that a decade ago would have been effectively outside the reach of the hobbyist. Right now you can order a four channel oscilloscope for less than what a new Xbox costs; but which one you’ll rack up more hours staring at slack-jawed is up to you.

10 MHz output from DIY frequency standard

Of course, these “cheap” pieces of equipment aren’t always perfect. [Paul Lutus] was pretty happy with his relatively affordable Siglent SDG 1025 Arbitrary Function Generator, but found its accuracy to be a bit lacking. Fortunately, the function generator accepts an external clock which can be used to increase its accuracy, so he decided to build one.

[Paul] starts off by going over the different options he considered for this project, essentially boiling down to whether or not he wanted to jump through the extra hoops required for an oven-controlled crystal oscillator (OCXO). But the decision was effectively made for him when his first attempt at using a more simplistic temperature controlled oscillator failed due to an unfortunate misjudgment in terms of package size.

In the end, he decided to spring for the OCXO, and was able to use the USB port on the front panel of the SDG 1025 to provide the power necessary for the crystal to warm up and remain at operating temperature. After he got the oscillator powered, he just needed to put it in a suitable metal enclosure (to cut down external interference) and calibrate it. [Paul] cleverly used the NIST WWV broadcast and his ears to find when his frequency standard overlapped that of the source, therefore verifying it was at 10 MHz.

Hackers love accuracy, and accordingly, we’ve seen a number of frequency standard builds ranging from extremely cheap to luxuriously overkill.

DIY CNC Sandblaster Writes Large

April 8, 2018 by Jenny List 12 Comments

CNC machinery, once a piece of workshop exotica, has become such a staple of projects within our sphere as to have become relatively unremarkable. A decent 3D printer can be had without mortgaging a small country, and the honor roll of CNC router builders is long and distinguished. But there is still plenty to surprise us in CNC, and [Fabien Chouteau]’s project shows us this with surprising simplicity. He’s eschewed a router or extruder, and instead fit an off-the-shelf CNC machine kit with a sandblaster.

If you are used to a sandblaster as a means for removing rust from pieces of your motor vehicle, then it’s fair to say that this one isn’t of that ilk. Instead, it’s used in the manner of an engraver, to sandblast a pattern or text onto a surface. This is something he shows us in the video below the break, with a piece of metal and a sheet of glass.The sandblaster itself features a 1.5-litre soda bottle and is driven by an airline.

On the electronic side, he replaced the controller that came with the kit with an STM32F469 discovery board and an Arduino CNC shield. He has a G-code controller from a previous project, to which he’s added a board with a touch screen to create a simple control interface.

This is by no means the only sandblaster we’ve featured, if your interests lie in that direction we can show you everything from the simple to the extreme.

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Art Deco Radio Gets FM Reception

April 7, 2018 by Tom Nardi 12 Comments

Taking a vintage radio and cramming it full of modern, Internet-connected, guts has long been a staple of the hacking and making scene. While some might see it as a crime to take what’s arguably a legitimate piece of history and turn it into nothing more than a slipshod case for the Raspberry Pi, we have to admit there’s a certain appeal to the idea. Taking the beauty of classic design and pairing it with more modern capabilities is getting the best of both worlds.

But this project by [Nick Koumaris] is a somewhat unique take on the concept. Rather than sacrificing a real vintage piece of hardware to house the electronics, he’s designed a 3D printable case that looks like a classic 1936 AWA Radiolette. But what’s really interesting to us is that he then puts a basic FM radio inside of it.

That’s right, no Internet radio streaming or smartphone Bluetooth compatibility here. It’s just a regular FM radio, not entirely unlike the kind of hardware you’d expect to be inside of a classic radio. Of course, it’s much more modern, and [Nick] actually built it himself from a TEA5767 FM radio module and an Arduino Pro Mini.

While functionally it might not be terribly exciting, we do appreciate that he went through the trouble to make a vintage-looking user interface for the radio. While physical buttons would arguably have been more appropriate given the era, the art deco inspired font and graphics that show on the device’s Nokia 5110 LCD do look really slick.

Purists will surely be happy to see another project where a piece of vintage piece of audio equipment wasn’t sacrificed at the Altar of Hack, but we’ve also played host to many projects which weren’t nearly as concerned with historical preservation.

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You Can Build Anything Out Of What Is Holding Your 97 Eagle Talon Together

April 7, 2018 by Brian Benchoff 29 Comments

We all know it, we all love it, and the guy parked outside of the 7-11 covered his car in it. What is it? Polyester body filler, better known by the almost generic trademark, Bondo. There’s a lot more you can do with Bondo than fairing in that sweet body kit, bro, and [Eric Strebel] is here to show you how far you can push the mechanical properties of polyester body filler.

We didn’t always have polyester body filler. In the days before OSHA, auto body workers would use a torch, bricks of lead, and a grinder. You can check out a video of the era before OSHA here. Needless to say, vaporizing and grinding lead in your shop isn’t the greatest idea, and there had to be a better way. This led Robert ‘Bondo Bob’ Spink to invent a much less toxic auto body filler that we now know as Bondo.

For the beginning of the demonstration, [Eric] mixes up a cup of polyester body filler with a few special additions: he’s using printer ink to get his mixture to something other than that one shade of pink we all know. Although Bondo is a bit too thick to cast, he did manage to put a little bit of it in a square mold, a PVC pipe, and applied a little to foam and wood. It’s enough for a demonstration, but for the actual ins and outs of machining Bondo we’re going to have to wait until [Eric]’s next video. Until then, you can check out this introduction below, or look at his previous work on free-form sculpting of uncured Bondo.

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Using Moiré Patterns To Guide Ships

April 7, 2018 by Steven Dufresne 27 Comments

[Tom Scott] ran across an interesting visual effect created with Moiré patterns and used for guiding ships but we’re sure it can be adapted for hacks somewhere. Without the aid of any motors or LED animation, the image changes as the user views it from different angles. When viewed straight on, the user sees vertical lines, but from the left they see a right-pointing arrow and from the right, they see a left-pointing arrow. It’s used with shipping to guide ships. For example, one use would be to guide them to the center point of a bridge. When the pilots see straight, vertical lines then they know where to steer the ship.

US patent 4,629,325, Leading mark indicator, explains how it works and how to make one. Two screens are separated from each other. The one in front is vertical but the one behind is split in two and angled. It’s this angle which creates the slants of the arrows when viewed from the left or right. We had to convince ourselves that we understood it correctly and a quick test with two combs showed that we did. See below for the test in action as well as for [Tom’s] video of the real-world shipping one.

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The Better RetroPie Handheld

April 7, 2018 by Brian Benchoff 15 Comments

The Raspberry Pi has become the best video game console on the planet. With RetroPi, anyone can play Super Mario 3, Doctor Mario, and even Doki Doki Panic. Adafruit’s PiGRRL Zero and [Wermy]’s reconfabulation of an old brick Game Boy to house a Raspi Zero and display have made the Raspberry Pi portable, along with all those retro games we love so dearly.

There’s a problem with these builds, though. They only use the Raspberry Pi Zero, and with that the limitations on emulation performance, and the Raspi 3 is far too big for a portable console. What’s the solution? It’s the greatest homebrew console ever created. For this year’s Hackaday Prize, [DeanChu] is building the Retro-CM3. It’s a retro handheld with a 3D printed enclosure, that’s powered by the Raspberry Pi Compute Module 3. Stand back, folks. We have a winner that will top the Raspberry Pi and 3D printing subreddits.

The key feature for this build is, of course, the raw processing power of the Raspberry Pi Compute Module 3. This is a Raspberry Pi 3 with 4 GB of eMMC stuffed onto a board that fits into an SODIMM socket. The pins on this device give you access to the GPIOs and the DSI connector. All you really need to turn this into an amazing vintage emulation console is a breakout board with a few buttons, power supply, and a display.

The extra components for this build include a 3.2 inch LCD using the DPI interface. There’s a speaker, and a 2000mAh battery. The real tricky part here is the custom PCB, breaking out the DPI pins on the Compute Module, adding a small speaker, and throwing a small STM32 to read the buttons. It’s an entire system, ready to be housed in a 3D printed enclosure.

This is, simply, the best Raspberry Pi portable you’ll ever see, at least until we get a Rasberry Pi Zero with the capabilities of the Pi 3. It’s an excellent use of the very small Compute Module, and one of the most polished Hackaday Prize entries we’ve seen thus far.

Applications Open: Ada Lovelace Fellowships For 2018 Open Hardware Summit

April 7, 2018 by Christopher Wang 2 Comments

The Open Source Hardware Association is now accepting applications for the Ada Lovelace fellowship which provides free admission to the Open Hardware Summit and a $500 travel stipend. One of OSHWA’s goals is to foster a more diverse community within open source. As part of this, Ada Lovelace Fellowships are open to women, LGBTA+, and people of color. There are a total of 10 fellowships available and applications are due by April 30th. The Open Hardware Summit will be held on September 27th at MIT.

The fellowship program, founded by Addie Wagenknecht and Alicia Gibb in 2013, builds on the ideal that Open Hardware is one way to reduce the barriers associated in access to technology. Removing some of the financial barriers associated with attending the Summit will help to ensure more people of diverse backgrounds are involved in shaping the Open Hardware world. In addition to the talks shared at the gathering, over the last several year OSWHA has been evolving the Open Hardware definition and an Open Hardware certification.

Disclaimer: [Christopher Wang] is a board member of the Open Source Hardware Association