Developed on Hackaday: The Top PCB dilemna

The Hackaday community offline password keeper is slowly coming together. A few days ago we received the top PCB for Olivier’s design (shown above). If you look at the picture below, you may see the problem we discovered when opening our package: the soldermask was the wrong color! Given the board is meant to be placed behind a tinted acrylic panel, this was quite a problem…

After using some spray paint, we managed to get to the point shown in the bottom left of the picture. The next task was to find the best way to illuminate the input interface with reverse mount LEDs. Using a CNC mill we machined openings (top right PCB) but also removed some epoxy on both PCB’s sides, thinking it would provide a better light diffusion. We then wrote part of the Mooltipass PWM code and took these pictures:

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DIY Linear Actuators For A Flight Sim


[Roland] has already built a few very cool and extremely realistic flight sims, but his latest project will put his current rig to shame. He’s building a six degree of freedom simulator based on homebuilt linear actuators of his own design.

The actuator is powered by a large DC motor moving timing belts along the length of the enclosure. These timing belts are connected to a shaft that’s coupled to the frame with a few bungee cords. The bungee cords are important; without them, the timing belts would be carrying all the load of the sim – not a good thing if these actuators are moving an entire cockpit around a living room.

Also on [Roland]‘s list of awesome stuff he’s building for his flight sims is a vibration system based on the BFF Shaker. This board takes data in from sim software and turns it into vibrations produced by either unbalanced DC motors or one of those ‘bass kicker’ transducers.

It’s all very cool stuff, and with all the crazy upgrades [Roland] is doing to his sim rig, he’s doing much better than paying $300/hour to rent a Beechcraft Baron.

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ISPnub – A Stand-Alone AVR In-System-Programmer Module

[Thomas] tipped us about his latest project: a stand-alone AVR programmer module named ISPnub. As you can see in the picture above, it is a simple circuit board composed of a main microcontroller (ATmega1284p), one button and two LEDs. Programming a target is a simple as connecting the ISPnub and pressing the button. The flashing operation success status is then shown using the green/red LED.

ISPnub gets its power from the target circuit so no external power supply is needed. It works over a wide voltage range: 1.8V to 5.5V. The module also features a programming counter which can be used to limit the number of programming cycles. A multi-platform Java tool is in charge of embedding the target flash contents with the ISPnub main firmware. The complete project is open source so you may want to check out the official GitHub repository for the firmware and the project’s page for the schematics.

Developed on Hackaday: 2 Days Left to Submit your Design!

We’re sure that many of Hackaday readers already know that one of the two main components of the Mooltipass project is a smart card, containing (among others) the AES-256 encryption key. Two weeks ago we asked if you’d be interested coming up with a design that will be printed on the final card. As usual, many people were eager to contribute and recently sent us a few suggestions. If you missed the call and would like to join in, it’s not too late! You may still send your CMYK vector image at mathieu[at]hackaday[dot]com by sunday. More detailed specifications may be found here.

In a few days we’ll also publish on Hackaday a project update, as we recently received the top and bottom PCBs for Olivier’s design. The low level libraries will soon be finished and hopefully a few days later we’ll be able to ship a few devices to developers and beta testers. We’re also still looking for contributors that may be interested in helping us to develop browser plugins.

The Mooltipass team would also like to thank our dear readers that gave us a skull on Hackaday projects!

Fake Audiophile Opamps Revealed


The OPA627 is an old, popular, and very high-end opamp found in gear cherished by the most discerning audiophiles. This chip usually sells for at least $15, but when [Zeptobars] found a few of these expensive chips on ebay going for $2, his curiosity was piqued. Something just isn’t right here.

[Zeptobars] is well known for his decapsulating and high-resolution photography skills, so he cut the can off a real OPA627, and dissolved one of the improbably cheap ebay chips to reveal the die. Under the microscope, he found an amazing piece of engineering in the real chip – laser trimmed resistors, and even a nice bit of die art.

The ebay chip, if it were real, would look the same. It did not. The ebay chip only contained one laser trimmed resistor and looks to be a much simpler circuit. After a bit of research, [Zeptobars] found it was actually an AD774 opamp. The difference is small, but the AD774 still has much higher noise – something audiophiles could easily differentiate with their $300 oxygen-free volume knobs.

This isn’t the first instance of component counterfeiting [Zeptobars] has come across. He’s found fake FTDI chips before, and we’re counting the days until he gets around to putting a few obviously fake ebay 6581 SID chips under the microscope.

Using SIMMs to Add Some Extra RAM on your Arduino UNO


A Single In-line Memory Module (SIMM) is a type of memory module containing Random Access Memory (RAM) which was used in computers from the early 1980s to the late 1990s (think 386, 486, Macintoshs, Atari STE…). [Rafael] just made a little library that allows you to interface these modules to the Atmega328p-based Arduino UNO in order to gain some memory space. His work was actually based on the great Linux on the 8bit ATMEGA168 hack from [Dmitry Grinberg] but some tweaks were required to make it work with [Rapfael]‘s SIMM but also to port it to the Arduino platform. The 30-pin SIMM shown above is capable of storing up to (hold on to your chairs…) 16MB but due to limited amount of available IOs on the Atmega328p only 256KB can be used. Our guess it that an SPI / I2C IO extender could lift this limitation. A quick (shaky) video is embedded after the break.

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Dirt Cheap Dirty Boards Offers Dirt Cheap PCB Fab

Dirt Cheap PCB


When your project is ready to build, it’s time to find a PCB manufacturer. There are tons of them out there, but for prototype purposes cheaper is usually better. [Ian] at Dangerous Prototypes has just announced Dirt Cheap Dirty Boards, a PCB fabrication service for times where quality doesn’t matter too much. [Ian] also discussed the service on the Dangerous Prototypes forum.

The boards are definitely cheap. $12 USD gets you ten 5 cm by 5 cm boards with 100% e-test and free worldwide shipping. You can even choose from a number of solder mask colors for no additional cost. [Ian] does warn the boards aren’t of the best quality, as you can tell in the Bus Pirate picture above. The silkscreen alignment has some issues, but for $1.2 a board, it’s hard to complain. After all, the site’s motto is “No bull, just crappy PCBs.”

The main downside of this service will be shipping time. While the Chinese fab house cranks out boards in two to four days, Hong Kong Post can take up to 30 days to deliver your boards. This isn’t ideal, but the price is right.