Salty? Tip Canister To Rage Quit Games

July 5, 2019 by 42 Comments

Do you long for a more pronounced way to rage quit video games? Smashing buttons comes naturally, of course, but this hurts the controller or keyboard. You can quit your longing, because [Insert Controller Here] has an elegant solution that’s worth its salt.

The Salty Rage Quit Controller is simple. The cup is filled with distilled water. When you pour salt in it, the two bolt terminals tell the Arduino Micro that the resistance in the water has decreased. The Micro sends whatever keystrokes you want, so you could call out your deadbeat medic before quitting, or just plain leave. [Insert Controller Here] has example code on his site to get you started. Click calmly past the break to watch the demo and build videos, or we’ll have to ban you for aggro.

With the right tools, you can turn anything into a game controller. Check out this car controller that uses Python and CAN bus sniffing.

Continue reading “Salty? Tip Canister To Rage Quit Games” →

How Not To Get Paid For Open Source Work

July 5, 2019 by 47 Comments

[Avi Press] recently made a Medium post sharing his thoughts on a failed effort to allow for paid users of an open source project. [Avi] is the author of Toodles, a tool to help organize and manage TODO items in software development. Toodles enjoyed unexpected popularity, and some of its users were large organizations. It seemed that Toodles was of value to people who could afford to pay, and they might even be willing to do so if [Avi] provided a way for them to do it. It turned out that the monetizing process was far from simple, and he ultimately wasn’t successful.

Before he even started, [Avi] thought carefully about things and found that even basic and preliminary questions were difficult to answer, such as:

  • How many people were actually using the software on a regular basis? Were they gaining quantifiable value from it?
  • What exactly would someone be buying? How would they pay, and how would it get delivered to them?
  • How could companies be charged for the tool while still offering it freely to individuals?
  • Is it even ethical to accept money for a project to which others have contributed? How could money be shared with contributors? How to fairly decide who gets how much?

In short, [Avi] discovered that much of the data he felt he needed in order to make these decisions didn’t exist, wasn’t easily accessible, or couldn’t be reliably measured. His experiment in adding a license and payment system (which always seemed to need more work than it should) yielded no fruit, as there were zero paid users anyway.

Regardless of whether “difficulty in shoehorning a paid license system into an open source project” should be filed under “Feature, not Bug” [Avi] does thoughtfully present the issues he encountered. Open source and getting paid are not necessarily mutually exclusive. Octoprint is one example of an open source project that eventually navigated these waters, but that doesn’t mean it was easy, nor does it mean there are established tools and processes.

Raspberry Pi Catches The Early Bird

July 4, 2019 by 11 Comments

If you live in an area with high bird activity, setting up a bird feeder and watching some hungry little fellows visit you can be a nice and relaxing pastime. Throw in a Raspberry Pi with some sensors and it can also be the beginning of your next IoT project, as it was the case for [sbkirby] with his Bird Feeder Monitor project.

To track the arrival and departure times of his avian visitors, [sbkirby] attached a set of capacitive touch sensors to each side of his bird feeder, and hooked them up to a Raspberry Pi Zero W via a CAP1188 breakout board. The data is published via MQTT to another Raspberry Pi that serves as backend and stores the data, as well as to an optional additional camera-equipped Pi that will take a picture of each guest along the way. Taking into account that precipitation might affect the sensor readings, he also checks the current weather situation to re-calibrate the sensors if necessary, and also to observe a change in the birds’ presence and eating behavior based on weather conditions.

It seems that sensor-based animal feeding will always serve as inspiration for some new projects, whether feeding the animal itself is the goal, like most recently this fish feeder has shown, or whether the eating behavior is monitored and used for further research such as this squirrel-based weather forecast system.

Understanding Elliptic Curve Cryptography And Embedded Security

July 4, 2019 by 26 Comments

We all know the usual jokes about the ‘S’ in ‘IoT’ standing for ‘Security’. It’s hardly a secret that security in embedded, networked devices (‘IoT devices’) is all too often a last-minute task that gets left to whichever intern was unfortunate enough to walk first into the office that day. Inspired by this situation, All About Circuits is publishing a series of articles on embedded security, with a strong focus on network security.

In addition to the primer article, so far they have covered the Diffie-Hellman exchange (using prime numbers, exponentiation and modular arithmetic) and the evolution of this exchange using elliptic curve cryptography (ECC) which prevents anyone from brute-forcing the key. Barring any quantum computers, naturally. All three articles should be understandable by anyone, with a simple, step-by-step format.

The upcoming articles will cover implementing security on microcontrollers specifically.  For those who cannot wait to learn more, Wikipedia has a number of articles on the topic of Elliptic Curve Cryptography (comparing it to the more older and still very common RSA encryption) specifically, as well as the Elliptic-Curve Diffie-Hellman key agreement protocol as discussed in the All About Circuits article.

A detail of note here is that the hardest problem in secure communications isn’t to keep the communications going, but to securely exchange the keys in the first place. That’s why a much much computationally expensive key exchange scheme using an asymmetric (or public-key) cryptography scheme  is generally used to set up the second part of the communications, which would use a much faster symmetric-key cryptography scheme, where both parties have the means to decode and encode messages using the same private key.

All the math aside, one does have to wonder about how one might denote ‘secure’ IoT. Somehow ‘SIoT’ doesn’t feel very catchy.

Sprucing Up A Bell & Howell Model 34 Oscilloscope

July 4, 2019 by 20 Comments

We’ll admit it, in an era when you can get a four channel digital storage oscilloscope with protocol decoding for a few hundred bucks, it can be hard not to see the appeal of analog CRT scopes from decades past. Sure they’re heavy, harder to use, and less capable, but they just look so cool. Who could say no to having one of these classic pieces of gear on their bench?

[Cody Nybo] certainly couldn’t. Despite the fact that he already has a digital scope, he couldn’t pass up the chance to add a Bell & Howell Schools Model 34 from circa 1973 to his collection. It needed a bit of TLC before it could be brought back into service, but now it’s all fixed up and ready to put in some work. Not bad for a piece of gear with nearly a half-century on the clock.

The restoration of the Model 34 was aided by the fact that [Cody] got the original manual and schematics for the scope in the deal, which he was kind enough to scan and upload for the rest of the class to enjoy. Those of you who have worked on older electronics can already guess where the scope needed the most love: all the capacitors needed to be swapped out for fresh ones. He also found a few resistors that were out of spec, and the occasional bad solder joint here and there.

Even if you’re not looking to repair your own middle-aged oscilloscope, his pictures of the inside of Model 34 are fascinating. The scope was sold as a kit, so the construction is surprisingly simple and almost entirely point-to-point. Of course, there’s something of a trade-off at work: [Cody] says it won’t display much more than 2.5 MHz before things start getting wonky. But then again, that’s a more than reasonable frequency ceiling for audio work and most hobbyist projects.

Oscilloscopes have come a long way since the days when they had to draw out their readings on a piece of paper. While newer devices have all but buried the classic analog scope, a beauty like this would still have a place of honor in our lab.

MIDI-Gurdy, MIDI-Gurdy, MIDI-Gurdy Man

July 4, 2019 by 19 Comments

The hurdy gurdy is the perfect musical instrument. It’s an instrument with a crank, and a mechanical wonderment of drone strings and weird chromatic keyboards. No other musical instrument combines the sweet drone of bagpipes with the aural experience of an eight-year-old attempting to play Hot Cross Buns on a poorly tuned violin.

Now, the hurdy gurdy is going digital. The Digi-Gurdy is [XenonJohn]’s entry into this year’s Hackaday Prize, and it’s exactly what it says on the tin: it’s a musical instrument that drones on and on, with keys plunking out a melody.

If you’re not familiar with a hurdy gurdy, this video is a varily good introduction. It’s a box with somewhere between four and six strings mounted on the outside. The strings vibrate by means of a wooden wheel powered by a crank. There’s a keyboard of sorts along the body of the instrument that ‘fret’ a single string providing the melody; all the other strings are drone strings that sound continuously. I think it was in, like, a Led Zeppelin video, man.

While it’s a slightly complicated build to make an analog hurdy gurdy, delving into the digital domain is easy: [XenonJohn] is building a hurdy gurdy that simply outputs MIDI commands with some buttons and a Teensy 3.6 microcontroller. The parts are 3D printed, and since this hurdy gurdy is completely digital, you can change the tuning of the drone strings without actually tuning them. Awesome.

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Hacked Calipers Make Automated Measurements A Breeze

July 4, 2019 by 22 Comments

Now, digital calipers with wired interfaces to capture the current reading are nothing new. But the good ones are expensive, and really, where’s the fun in plugging a $75 cable into a computer? So when [Max Holliday] was asked to trick out some calipers for automating data capture, he had to get creative.

[Max] found that cheap Harbor Freight digital calipers have the telltale door that covers a serial connector, making them a perfect target for hacking. A little Internet sleuthing revealed the pinout for the connector as well as some details on the serial protocol used by most digital calipers: 24-bit packets is six four-bit words. [Max] used his SAM32, a neat open-source board with both a SAMD51 and an ESP32 that can run CircuitPython. An inverting buffer interfaces the serial lines to the board, which is just the right size to mount on the back of the caliper head. It’s hard to tell how [Max] is triggering readings, but the SAM32 is mounted as a USB device and sends keystrokes directly to a spreadsheet – yes, with the ESP32 it could have been wireless, but his client specifically requested a wired setup. Taking multiple readings is easy now that the user never has to swap calipers for a pen.

Cheap calipers like these are pretty hackable – you can add Bluetooth, turn them into DROs for a milling machine, or even make them talk.