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

These Gorgeous Robot Parts Are Hand-Made

April 7, 2018 by Donald Papp 12 Comments

[Dickel]’s robot MDi #4 has been in progress for several years, but what we wanted to draw your attention to is the way the parts have been fabricated and what kind of remarkable results are possible with careful design, measurement, cutting, and finishing. Much of MDi #4 was made by hand-cutting and drilling sheets of high impact polystyrene (HIPS) with a utility knife and layering them as needed. Epoxy and aluminum provide gap filling and reinforcement of key sections, and fiberglass took care of one of the larger sections.

The process [Dickel] follows is to prototype using cardboard first. Parts are then designed carefully in CAD, and printed out at a 1:1 scale and glued to sheets of polystyrene. Each sheet is cut and drilled by hand as necessary. Layers are stacked and epoxied, embedding any hardware needed in the process. Two examples of embedding hardware include sealing captive nuts into parts with epoxy, or using aluminum to add reinforcement. After some careful sanding, the pieces look amazing.

Scroll down a bit on that project page and you’ll see plenty of great photos of the process [Dickel] used. A video highlighting the head and a video showing the careful work that goes into making each part are embedded below.

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Retrofit Temperature Control To A Soldering Station

April 7, 2018 by Jenny List 1 Comment

We’ve probably all seen USB soldering irons advertised for very little money, and concluded that they might not necessarily be the most useful of tools. The cheapest of these lack any real temperature regulation. Enter [Paulo Bruckmann], who has attached a thermistor to his iron with Kapton tape, added an Arduino Uno clone with rotary encoder and Nokia LCD, and put the result in a 3D printed case for a tiny and low powered temperature controlled soldering station. The claimed cost is only $10, which seems credible given the low price of Arduino clones.

The software provides the expected PID control, with the advantage of very quick warm-up due to the tip’s tiny size. The power source is 9 V rather than a USB 5 V, so the combination gives an iron capable of working on much larger joints than when unmodified. He therefore seems to have created what appears to be a significantly more capable iron from this unpromising start, something we find quite impressive. Take a look at his video below the break.

We reviewed one of these little irons last year, and found it to be a toy, but not a joke. Meanwhile we’ve seen some other mods for them, including a pair of desoldering tweezers.

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Reviving An Electron Microscope With Arduino

April 7, 2018 by Tom Nardi 20 Comments

We don’t know about you, but when our friends ask us if we want to help them fix something, they’re usually talking about their computer, phone, or car. So far it’s never been about helping them rebuild an old electron microscope. But that’s exactly the request [Benjamin Blundell] got when a friend from a local hackerspace asked if he could take a look at a vintage Cambridge Stereoscan 200 they had found abandoned in a shed. Clearly we’re hanging out with the wrong group of people.

As you might imagine, the microscope was in desperate need of some love after spending time in considerably less than ideal conditions. While some of the hackerspace members started tackling the hardware side of the machine, [Benjamin] was tasked with finding a way to recover the contents of the scope’s ROM. While he’s still working on verification, the dumps he’s made so far of the various ROMs living inside the Stereoscan 200 have been promising and he believes he’s on the right track.

The microscope uses a mix of Texas Instruments 25L32 and 2516 chips, which [Benjamin] had to carefully pry out after making sure to document everything so he knew what went where. A few of the chips weren’t keen on being pulled from their home of 30-odd years, so there were a few broken pins, but on the whole the operation was a success.

Each chip was placed in a breadboard and wired up to an Arduino Mega, as it has enough digital pins to connect without needing a shift register. With the wiring fairly straightforward, [Benjamin] just needed to write up some code to read the contents of the chip, which he has graciously provided anyone else who might be working on a similar project. At this point he hasn’t found anything identifiable in his ROM dumps to prove that they’ve been made successfully, all he really knows right now is that he has something. At least it’s a start.

More and more of these older electron microscopes are getting a second lease on life thanks to dedicated hackers in their home labs. Makes you wonder if there’s ever going to be a piece of hardware the hacker community won’t bend to their will.

Circuit-Sword Delivers Retro Justice

April 6, 2018 by Kerry Scharfglass 13 Comments

You can’t search for “retro gaming” without hitting a plethora of single board computers attached to all manner of controls, batteries, etc. Often these projects have an emphasis on functionality above all else but [Kite]’s Circuit-Sword is different. The Circuit-Sword is the heart of a RaspberryPi-based retro gaming machine with an enviable level of fit and finish.

Fundamentally the Circuit-Sword is a single board computer built around a Raspberry Pi Compute Module 3. We don’t see many projects which use a Compute Module instead of the full Pi, but here it is a perfect choice allowing [Kite] to useful peripherals without carrying the baggage of those that don’t make sense for a portable handheld (we’re looking at you, Ethernet). The Circuit-Sword adds USB-C to quickly charge an onboard LiPo (rates up to 1.5A available) and the appropriate headers to connect a specific LCD. The Compute Module omits wireless connectivity so [Kite] added an SDIO WiFi/Bluetooth module. And if you look closely, you may notice an external ATMega mediating a familiar looking set of button and switches.

We think those buttons and switches are the most interesting thing going on here, because the whole board is designed to fit into an original GameBoy enclosure. It turns out replacement enclosures are available from China in surprising variety (try searching for “gameboy housing”) as are a variety of parts to facilitate the installation of different screen options and more. One layer deeper in the wiki there are instructions for case mods you may want to perform to make everything work optimally. The number of possible options the user can mod-in are wide. Extra X/Y buttons? Shoulder buttons on the back? Play Station Portable-style slide joysticks? All detailed. For even more examples, try searching the SudoMod forums. For example, here’s a very visual build log by user [DarrylUK].

The case mod instructions are worth a glance even if you have no intent to build a device. There are some clever techniques to facilitate careful alignment of buttons and accurate hole drilling. Predicting their buyers might want a variety of options, [Kite] added reference drill holes in the PCB for the builder to re-drill for mounting buttons or joysticks. To facilitate adding status LEDs externally there is a tiny PCB jig included. There are even instructions for adding a faux game cartridge for the complete look.

If you want to buy one (we certainly do!) [Kite] does group buys periodically. Check out the wiki for links to the right interest form.

Thanks [Speednut Dave] for the tip!