Mouse Mis-Clicking? We Got You.

A mouse with malfunctioning buttons can be a frustrating to deal with — and usually a short leap to percussive maintenance. Standard fixes may not always last due to inferior build quality of the components, or when the microswitch won’t close at all. But, for mice that double/triple-click, will release when dragging, or mis-click on release, this Arduino-based hack may be the good medicine you’re after.

Instructables user [themoreyouknow]’s method cancels click malfunctions by latching the mouse’s controller switch trace to ‘on’ when pressed, keeping it there until the button normally closed contact closes again completely. Due to the confined spaces, you’ll want to use the smallest Arduino you can find, some insulating tape to prevent any shorts, and care to prevent damaging the wires this process adds to the mouse when you cram it all back together.

Before you take [themoreyouknow]’s guide as dogma, the are a few caveats to this hack; they are quick to point out that this won’t work on mice that share two pins between three buttons — without doing it the extra hard way, and that this might be trickier on gaming or other high-end mice, so attempt at your own peril.

Speaking of gaming mice, we recently featured a way to add some extra functionality to your mouse — cheating optional — as well as how to stash a PC inside an old Logitech model.

A Diode by Any Other Name

As active devices go, it doesn’t get much simpler than a diode. Two terminals. Current flows in one direction and not in the other. Simple, right? Well, then there are examples with useful side effects like light emitting diodes. [GreatScott] points out that there are other useful diodes and, in particular, he posted a video covering Schottky and Zener diodes.

These special diodes have particular purposes. A Schottky diode has a very low voltage drop and fast switching speed. Zener diodes have application in simple voltage regulation.

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Floating Ants and Drops of Liquid with an Acoustic Levitator

Amuse your friends, amaze your enemies, and perplex ants and other insects, insofar as they are capable of perplexment. Accomplish all this and more with this handy dandy homebrew acoustic levitator.

Before anyone gets to thinking about using this technique to build a hoverboard that actually hovers, it’s best that you scale your expectations way, way down. Still, being able to float drops of liquid and small life forms is no mean feat, and looks like a ton of fun to boot. [Asier Marzo]’s Instructable’s post fulfills a promise he made when he first published results for what the popular press then breathlessly dubbed a “tractor beam,” which we covered back in January. This levitator clearly has roots in the earlier work, what with 3D-printed hemispherical sections bristling with ultrasonic transducers all wired in phase. A second section was added to create standing acoustic waves in the middle of the space, and as the video below shows, just about anything light enough and as least as cooperative as an ant can be manipulated in the Z-axis.

There’s plenty of room to expand on [Asier]’s design, and probably more practical applications than annoying bugs. Surface-mount devices are pretty tiny — perhaps an acoustic pick and place is possible?

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Control The Air Conditioning With Slack

[Raphael Baron] needed a better way to control his office’s air conditioning units. Sure, they have remotes, but that’s too easy. [Raphael] came up with a solution that uses an ESP8266, a computer, IR LEDs, and a bot that runs on Slack.

[Raphael] built a prototype of the ESP8266 hardware on protoboard and used it to read and record the IR signals from the remote. Once he’d figured out the issues he was having with the IR library he was using, he could use it to send the IR commands to the AC unit. Since their office has two AC units, [Raphael] built a second prototype which had two IR LEDs but didn’t have the IR receiver. Using this he could turn both AC units on and off and set their temperatures.

For the server, [Raphael] turned to Clojure, a dialect of Lisp, which provides easy access to the Java Framework, mainly to get practice working with the language. The server’s main responsibility is to use Slack’s real-time API to listen for messages from a Slack bot and forward them to the ESP. In this way, a user talking to the Slack bot can send it messages which the server forwards to the microcontroller which, in turn, parses the messages and send IR commands to the AC units.

[Raphael] admits that this isn’t the most advanced, professional stuff, but it doesn’t matter. The schematics for the ESP8266 board and the code for both the ESP board and the server are available on GitHub. There seems to be a lot of hacks using Slack, such as this NERF Turret controlled by a Slack bot.  Or this jukebox that users can interact with by talking to a Slack bot.

Fake Ram: Identifying a Counterfeit Chip

[Robert Baruch‏] had something strange on his hands. He had carefully decapped 74LS189 16×4 static RAM, only to find that it wasn’t a RAM at all. The silicon die inside the plastic package even had analog elements, which is not what one would expect to find in an SRAM. But what was it? A quick tweet brought in the cavalry, in the form of chip analysis expert [Ken Shirriff].

[Ken] immediately realized the part [Robert] had uncovered wasn’t a 74 series chip at all. The power and ground pins were in the wrong places. Even the transistors were small CMOS devices, where a 74 series part would use larger bipolar transistors. The most glaring difference between the mystery device and a real LS819 was the analog elements. The mystery chip had a resistor network, arranged as an R-2R ladder. This configuration is often used as a simple Digital to Analog Converter (DAC).

Further analysis of the part revealed that the DAC was driven by a mask ROM that was itself indexed using a linear feedback shift register. [Ken] used all this information to plot out the analog signal the chip would generate. It turned out to be a rather sorry looking sine wave.

The mystery part didn’t look like any function generator or audio chip of the era. [Ken] had to think about what sort of commodity part would use lookup tables to generate an audio waveform. The answer was as close as his telephone — a DTMF “touch tone” generator, specifically a knockoff of a Mostek MK5085.

Most investigators would have stopped there. Not [Ken] though. He delved into the construction and function of the DTMF generator. You can find the full analysis on his site. This isn’t [Ken’s] first rodeo with decapped chips. He’s previously examined the Intel 8008 and presented a talk on silicon reverse engineering at the 2016 Hackaday Superconference. [Robert] has also shown us how to pop the top of classic ceramic integrated circuits.


Horizontal Magnetic Levitation Experiments

Levitating chairs from the Jetsons still have a few years of becoming a commercial product though they are fun to think about. One such curious inventor, [Conor Patrick], took a deep dive into the world of maglev and came up with a plan to create a clock with levitating hands. He shares the first part of his journey to horizontal levitational control.

[Conor Patrick] bought an off-the-shelf levitation product that was capable of horizontal levitation. Upon dissecting it he found a large magnet, four electromagnet coils, and a hall effect sensor. These parts collectively form a closed-loop control to hold an object at a specific distance. He soon discovered that in fact, there were just two coils energized by H-bridges. His first attempt at replicating the circuit, he employed a breadboard which worked fine for a single axis model. Unfortunately, it did not work as expected with multiple coils.

After a few iteration and experiments with the PID control loop, he was able to remove unwanted sensor feedback as well as overshoot in control current. He finally moved to a Teensy with a digital PD loop. The system works, but only marginally. [Conor Patrick] is seeking help from the control loop experts out there and that is the essence of the OSHW world. The best part of this project is that it is a journey that involves solving one problem at a time. We hope to see some unique results in the future.

We have covered Acoustic Levitation in the past and the Levitating Clock on a similar beat. We’re certain a more refined approach is on the horizon since many of us are now looking at making one to experiment with on our workbench.

Hackaday Prize Entry: MappyDot, a Micro Smart LiDAR Sensor

[Blecky]’s entry to the Hackaday Prize is MappyDot, a tiny board less than a square inch in size that holds a VL53L0X time-of-flight distance sensor and can measure distances of up to 2 meters.

MappyDot is more than just a breakout board; the ATMega328PB microcontroller on each PCB provides filtering, an easy to use  I2C interface, and automatically handles up to 112 boards connected in a bus. The idea is that one or a few MappyDots can be used by themselves, but managing a large number is just as easy. By dotting a device with multiple MappyDots pointing in different directions, a device could combine the readings to gain a LiDAR-like understanding of its physical environment. Its big numbers of MappyDots [Blecky] is going for, too: he just received a few panels of bare PCBs that he’ll soon be laboriously populating. The good news is, there aren’t that many components on each board.

It’s great to see open sourced projects and tools in which it is clear some thought has gone into making them flexible and easy to use. This means they are easier to incorporate into other work and helps make them a great contestant for the Hackaday Prize.