Mini Library For Kids Gets Blinky Lights And Solar Upgrade

June 28, 2020 by 1 Comment

Reading is big in Québec, and [pepelepoisson]’s young children have access to a free mini library nook that had seen better days and was in dire need of maintenance and refurbishing. In the process of repairing and repainting the little outdoor book nook, he took the opportunity to install a few experimental upgrades (link in French, English translation here.)

The mini library pods are called Croque-Livres, part of a program of free little book nooks for children across Québec (the name is a bit tricky to translate into English, but think of it as “snack shack, but for books” because books are things to be happily devoured.)

After sanding and repairs and a few coats of new paint, the Croque-Livres was enhanced with a strip of WS2812B LEDs, rechargeable battery with solar panel, magnet and reed switch as door sensor, and a 3.3 V Arduino to drive it all. [pepelepoisson]’s GitHub repository for the project contains the code and CAD files for the 3D printed pieces.

The WS2812B LED strip technically requires 5 V, but as [pepelepoisson] found in his earlier project Stecchino, the LED strip works fine when driven directly from a 3.7 V lithium-polymer cell. It’s not until around 3 V that it starts to get unreliable, so a single 3.7 V cell powers everything nicely.

When the door is opened, the LED strip lights up with a brief animation, then displays the battery voltage as a bar graph. After that, the number of times the door as been opened is shown on the LED strip in binary. It’s highly visual, interactive, and there’s even a small cheat sheet explaining how binary works for anyone interested in translating the light pattern into a number. How well does it all hold up? So far so good, but it’s an experiment that doesn’t interfere at all with the operation of the little box, so it’s all good fun.

Reproduction 1960s Computer Trainer Really Pushes Our Buttons

June 28, 2020 by 13 Comments

If you were selling computers in the early 1960s you faced a few problems, chief among them was convincing people to buy the fantastically expensive machines. But you also needed to develop an engineering force to build and maintain said machines. And in a world where most of the electrical engineers had cut their teeth on analog circuits built with vacuum tubes, that was no easy feat.

To ease the transition and develop some talent, Digital Equipment Corporation went all out with devices like the DEC H-500 Computer Lab, which retrocomputing wizard [Michael Gardi] is currently building a reproduction of. DEC’s idea was to provide a selection of logic gates, flip flops, and other elements of digital electronics that could be hooked together into more complicated circuits. We can practically see the young engineers in their white short-sleeve shirts and skinny ties laboring over the H-500 in a lab somewhere.

[Mike] is fortunate enough to have have access to an original H-500, but he wants anyone to be able to build one. His project page and the Instructables post go into great detail on how he made everything from the front panel to the banana plug jacks; almost everything in the build aside from the wood frame is custom 3D printed to mimic the original as much as possible. But the pièce de résistance is those delicious, butterscotch-colored DEC rocker switches. Taking some cues from custom switches he had previously built, he used reed switches and magnets to outfit the 3D printed rockers and make them look and feel like the originals. We can’t wait for the full PDP build.

Hats off to [Mike] for another stunning reproduction from the early years of the computer age. Be sure to check out his MiniVac 601 trainer, the Digi-Comp 1 mechanical computer, and the paperclip computer. If you’d like to pick [Mike’s] brain about this or any of his other incredible projects, he’ll be joining us for a Hack Chat in August.

Thanks to [Granzeier] for the tip!

Calcuino Is An Arduino Calculator

June 28, 2020 by 4 Comments

All by itself, a calculator based on an Arduino isn’t necessarily very novel. However, [Danko Bertović] of Volos Projects has a nice board that, of course, looks like a calculator. There are 16 keys and an LED display. But it seems to us the real value would be using this as a base for other projects.

As an inexpensive development board, it’s handy to have a simple processor with a keyboard and a display. There’s some extra I/O pins and the first example in the video below shows using the setup as a simple organ, for example. We’d love to see an option to replace the LED with an LCD and maybe even some different CPU options, as well.

The board is essentially an Arduino with a standard USB to serial chip and a MAX7219 display driver. Of course, you could breadboard up all of these things, but it wouldn’t be as neat looking. One unusual thing about the keyboard is that it is not multiplexed. Each button has a label that indicates what Arduino pin it connects with. So key 6 connects to pin 6 and pin A2 connects to the key marked =/A2.

With the availability of inexpensive PC boards, we’re seeing many nice designs out there that would be easy to repurpose for other things. For example, we thought this board would easily run the Kim Uno, with some modifications to the I/O routines. Might even be able to work out a clone of an even older computer to fit on the board.

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A Dead Macbook GPU Shouldn’t Stop You, With This BGA Soldering Hack

June 28, 2020 by 42 Comments

On some 2011 Macbook Pro models, there is a tendency for the Radeon GPU to fail. This should mean game over for the computer, but surprisingly salvation is offered by its having not one but two GPUs on board. The Intel processor also has a GPU, and Apple use a pile of logic in an FPGA to switch at will between them. The community have produced fresh FPGA code to revive a dead Mac on its Intel GPU, but at the expense of losing brightness control. [Ayilm1] has brought back the brightness with a clever BGA reworking hack that gains access to a brightness control line present on the Intel BD82HM65 Platform Controller Hub chip but not used in the Macbook.

We’re used to impressive soldering work here at Hackaday, and we’ve seen our share of wiring direct to the balls on an upturned BGA chip. This is a similar idea but at another level, as a section of the top insulation on an in-place BGA is removed to expose the microvia above the ball carrying the required signal. A tiny wire is soldered to the exposed pad and taken to a piece of copper tape stuck down to provide mechanical strength, and a piece of enameled copper wire is run from that to the other side of the PCB where lies its destination. It comes with FPGA code to take advantage of it, but even for non-Macbook owners, it’s an extremely impressive piece of work. It’s not the first fine-soldering Macbook fix we’ve seen, either.

Thanks [lightpink784] for the tip.

Hacking A ThinkPad USB-C Adapter

June 28, 2020 by 29 Comments

USB-C has brought the world much more powerful charging options in a slimline connector. With laptop chargers and portable battery packs using the standard, many with older hardware are converting their devices over to work with USB-C. [victorc] was trying to do just that, purchasing an adapter cable to charge a ThinkPad. Things didn’t quite work out of the box, so some hacking was required.

The problem was the power rating of the adapter cable, versus the battery pack [victorc] was trying to use. In order to allow the fastest charging rates, the adapter cable features a resistor value which tells the attached Lenovo laptop it can draw up to 90 W. The battery pack in question could only deliver 45 W, so it would quickly shut down when the laptop tried to draw above this limit.

To rectify this, [victorc] looked up the standard, finding the correct resistor value to set the limit lower. Then, hacking open the cable, the original resistor on the Lenovo connector was removed, and replaced with the correct value. With this done, the cable works perfectly, and [victorc] is able to charge their laptop on the go.

For all the benefits USB-C has brought, there’s been plenty of consternation, too. Whether this clears up, only time will tell!

DIY Hand Mixer Whips Coffee Into Shape

June 27, 2020 by 13 Comments

Along with the substantial rise in bread baking over the last few months, many people have been whipped into a frenzy over this tasty-looking frothy coffee beverage called Dalgona. It’s like a caffeinated meringue made from instant coffee, sugar, boiling water, and a whole lot of air that is then spooned onto milk or milk and ice.

Sure, you can use a whisk to mix it up if you don’t mind doing so continuously and vigorously for at least a full three minutes. [HimanshuS8] quickly got tired of making his wife’s coffee this way, and designed a small electric hand mixer especially for this task. [HimanshuS8] happens to be a hardware design engineer, which is why it looks so minimalist and beautiful.

The inside is just as beautiful, mixing junk bin parts like the 6 V motor from a cassette deck with printed gears and beaters. At the risk of reviving an old debate, we hope [HimanshuS8] used food-safe filament for those. If you replicate this, you could try to design it around standard metal beaters instead. Check out the demo after the break while you wait for the water to boil.

Coffee makes everything better, including 3D prints — the high cellulose content in coffee waste has been shown to drastically improve print strength.

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433 On A Stick

June 27, 2020 by 15 Comments

Cheap 433 MHz wireless switches are a tempting way to enter the world of home automation, but without dedicated hardware, they can be less easy to control from a PC. That’s the position [TheStaticTurtle] was in, so the solution was obvious. Build a USB 433 MHz transceiver.

At the computer end is a CH340 USB-to-serial chip and the familiar ATmega328 making this a compact copy of the Arduino. At the RF end are a pair of modules for transmit and receive, unexpectedly with separate antennas. This device is a second revision, after initial experiments with a single antenna connector and an RF switch proved not to work. On the software side the Arduino uses the rc-switch library, while on the PC side there’s a Python library to make sense of it all. The code and hardware files are all on GitHub, should you wish to experiment.

The problem of making a single antenna transceiver is not for the faint-hearted RF engineer, as while diode switches seem on paper to deliver the goods, they can be extremely difficult to get right and preserve linearity. We’re curious that a transceiver module wasn’t used instead, but we’re guessing that cost played a significant part in the equation.

Over the years we’ve featured quite a few fascinating 433 MHz projects, like this TP-Link router conversion.