App note: Advanced LED rework procedure for video wall and signage applications

via Dangerous Prototypes


App note from OSRAM about LED rework on signages and their demand for more sophosticated tools. Link here (PDF)

SMT LEDs have became more and more popular in video wall and signage applications, replacing radial LEDs. This leads to more difficulties during the repair or replacement of failed LEDs on PCBs, especially for QFN (Quad Flat No-lead) packages, as there is no exposed lead. This application note provides basic information on how to rework the SMT LEDs in video wall and signage applications. To describe the rework process the DISPLIX Oval LED was chosen an example, as the rework of this LED is more challenging due to the lack of exposed lead and the oval lens on top. However, the procedure is also suitable for other LEDs. In this application note details on the materials used, examples of suitable equipment and the process are presented and described. Finally, the test results of the LED after the rework process are presented, showing that in this case the rework procedure did not cause any damage to the LED itself.

App note: Matrix LED and where they are used

via Dangerous Prototypes


White paper about matrix LED usage from Integrated Silicon Solution Inc. (ISSI). Link here (PDF)

People today come in contact with a wide range of consumer electronics (CE) devices in their daily lives. CE devices have become increasingly complex with added functionality enabled by MCU’s which provide the intelligence for automating functions. Control panels used in appliances and other equipment leverage MCUs and several integrated circuits to enable functions, such as sensing, process control and user interface (UI).

The user interface consists of input controls, visual and audio feedback used to configure the product to perform complex tasks. An aesthetically pleasing UI is a major differentiating feature for home appliances such as ovens, washing machines and refrigerators. Home appliance UIs commonly use capacitive or inductive touch sensing to provide an easy to clean interface unmatched by mechanical buttons. In addition to touch sensing, a UI has to provide audio and visual feedback in response to the user selection. The UI may not be the most important factor in determining the commercial success of CE devices. However, once parity is established on the major functions such as washing capacity, energy efficiency, etc, the UI becomes a key differentiator. Today, parity has been established on most of the important factors making the UI a product differentiating factor.

As the trend continues to move away from purely mechanical switches to a fully electronic interface expect to see demand for LEDs and drivers to continue increasing.

These Small PCBs are Made for Model Rocketry

via hardware – Hackaday

Model rocketry hobbyists are familiar with the need to roll their own solutions when putting high-tech features into rockets, and a desire to include a microcontroller in a rocket while still keeping things flexible and modular is what led [concretedog] to design a system using 22 mm diameter stackable PCBs designed to easily fit inside rocket bodies. The system uses a couple of 2 mm threaded rods for robust mounting and provides an ATTiny85 microcontroller, power control, and an optional small prototyping area. Making self-contained modular sleds that fit easily into rocket bodies (or any tube with a roughly one-inch inner diameter) is much easier as a result.

The original goal was to ease the prototyping of microcontroller-driven functions like delayed ignition or altimeter triggers in small Estes rockets, but [concretedog] felt there were probably other uses for the boards as well and made the design files available on GitHub. (Thanks!)

We have seen stackable PCBs for rocketry before with the amazingly polished M3 Avionics project, but [concretedog]’s design is much more accessible to some hobbyist-level tinkering; especially since the ATTiny85 can be programmed using the Arduino IDE and the boards themselves are just an order from OSH Park away.

[via Dangerous Prototypes Blog]


Philips Hue – control anything hack

via Dangerous Prototypes


Fred writes:

To be honest, my recent simple relay hack wasn’t really all that great. It just used the high power constant current output to drive a SSR. It wasn’t ideal, but it worked. I decided that it was worth the effort to track down some more useful outputs and properly detect the desired state of the bulb.
All it took was a little bit of poking around and probing the pins of the SAM R21 microcontroller with an oscilloscope. It wasn’t actually that hard. On the B22 bayonet fitting version of the bulb I found some.

More details on his blog here, 0xFRED.

You’ve Never Seen A Flipping Eyeball Like This One!

via hardware – Hackaday

Inspired by some impressive work on textile flip-bit displays, and with creative steampunk outfits to create for Christmas, [Richard Sewell] had the idea for a flippable magnetic eye in the manner of a flip-dot display. These devices are bistable mechanical displays in which a magnet is suspended above a coil of wire, and “flipped” in orientation under the influence of a magnetic field from the coil.

In [Richard]’s case the eyeball was provided by a magnetic bead with a suitable paint job, and the coil was a hand-wound affair with some extremely neat lacing to keep it all in place. The coil requires about 200 mA to ensure the eye flips, and the job of driving it is performed by a Digispark ATTiny85 board with an LM293 dual H-bridge driver upon which the two bridges are wired in parallel. The whole is mounted in the centre of a charity shop brooch that has been heat-treated to give a suitable aesthetic.

You can see the eyeball in all its glory in the two videos below the break, and should you be curious you can also read our write-up of the original pieces from [Irene Posch] that inspired it.

And here they eye is in close-up.

Stretched PC Case Turned GPU Cryptominer

via hardware – Hackaday

We don’t do financial planning here at Hackaday, so we won’t weigh in on the viability of making money mining cryptocurrency in such a volatile market. But we will say that if you’re going to build a machine to hammer away at generating Magical Internet Monies, you might as well make it cool. Even if you don’t turn a profit, at least you’ll have something interesting to look at while you weep over your electricity bill.

Sick of seeing the desktop machine he built a decade ago gathering dust, [plaggle24w5] decided to use it as the base for a cryptocurrency mining rig. Of course, none of the original internals would do him any good, but the case itself ended up being a useful base to expand on. With the addition of some 3D printed components, he stretched out the case and installed an array of video cards.

To start with, all the original plastic was ripped off, leaving just the bare steel case. He then jammed a second power supply into the original optical drive bays to provide the extra power those thirsty GPUs would soon be sucking down. He then designed some 3D printed arms which would push out the side panel of the case far enough that he could mount the video cards vertically alongside the case. Three case fans were then added to the bottom to blow air through the cards.

While [plaggle24w5] mentions this arrangement does work with the case standing up, there’s obviously not a lot of air getting to the fans on the bottom when they’re only an inch or so off the ground. Turning the case on its side, with the motherboard parallel to the floor, allows for much better airflow and results in a measurable dip in operating temperature. Just hope you never drop anything down onto the exposed motherboard…

Mining Bitcoin on desktop computers might be a distant memory, but the latest crop of cryptocurrencies are (for now) giving new players a chance to relive those heady early days.