Quartet Of SMD Resistors Used To Sense Z-Axis Height

January 27, 2019 by 34 Comments

Here’s a neat trick for your next 3D-printer build or retrofit: a Z-axis sensor using a DIY strain gauge made from SMD resistors. We’re betting it could have plenty of other applications, too.

Conventional load cells, at least the ones you can pick up cheaply from the usual sources or harvest from old kitchen or bathroom scales, are usually way too big to be used on the extruder of a 3D-printer. [IvDm] wanted to build a touch sensor for his Hybercube printer, so he built his own load cell to do it. It consists of four 1000 ohm SMD resistors in the big 2512 device size. He mounted them to an X-shaped PCB and wired them in the classic Wheatstone bridge configuration, with two resistors on one side of the board and two on the other.

The extruder mounts into a hole in the center of the board and floats on it. Through an HX711 load cell driver chip, the bridge senses the slight flex of the board when the extruder bottoms out on the bed, and an ATtiny85 pulls a limit switch input to ground. [IvDm] even did some repeatability testing with this sensor and it turned out to be surprisingly consistent. The first minute or so of the video below shows it in action on the Hypercube.

We found the use of SMD resistors as strain gauges pretty clever here, but there’s plenty to do with off-the-shelf load cells: measuring how much filament is left on a roll, checking the thrust of a model rocket engine, or even figuring out if you’re peeing correctly.

Continue reading “Quartet Of SMD Resistors Used To Sense Z-Axis Height” →

Open Source Fader Bank Modulates Our Hearts

January 27, 2019 by 9 Comments

Here at Hackaday, we love knobs and buttons. So what could be better than one button? How about 16! No deep philosophy about the true nature of Making here; [infovore], [tehn], and [shellfritsch] put together a very slick, very adaptable bank of 16 analog faders for controlling music synthesis. If you don’t recognize those names it might help to mention that [tehn] is one of the folks behind monome, a company built on their iconic grid controller. Monome now produces a variety of lovingly crafted music creation tools.

Over the years we’ve written about some of the many clones and DIY versions of the monome grid controller, so it’s exciting to see an open source hardware release by the creators themselves!

The unambiguously named 16n follows in the footsteps of the monome grid in the sense that it’s not really for something specific. The grid is a musical instrument insofar as it can be connected to a computer (or a modular synth, etc) and used as a control input for another tool that creates sound. Likewise, the 16n is designed to be easily integrated into a music creation workflow. It can speak a variety of interfaces, like purely analog control voltage (it has one jack per fader), or i2c to connect to certain other monome devices like Ansible and Teletype. Under the hood, the 16n is actually a Teensy, so it’s fluent in MIDI over USB and nearly anything else you can imagine.

Continue reading “Open Source Fader Bank Modulates Our Hearts” →

Casting Concrete With 3D Printed Molds

January 27, 2019 by 13 Comments

[Thomas Sanladerer] wanted to create some molds using 3D printing for concrete and plaster. He used a delta printer with flexible filament and documented his process in the video below.

If you’ve printed with flexible filaments before, you know you need an extruder that has a contained path. [Tom] borrowed a printer, but it didn’t have that kind of set up. The first step was to swap extruders with another printer.

Continue reading “Casting Concrete With 3D Printed Molds” →

Rebuilding The First Vocal Encryption System

January 27, 2019 by 12 Comments

Back in the early days of radio, it was quickly apparent that the technology would revolutionize warfare, but only if some way could be found to prevent enemies from hearing what was said. During World War II, the Allies put a considerable amount of effort into securing vocal transmissions, resulting in a system called SIGSALY – 50 tons of gear developed by Bell Laboratories with the help of Alan Turing that successfully secured communications between the likes of Churchill and Roosevelt during the war.

Now, a small piece of the SIGSALY system lives again, in the form of a period-faithful reproduction of the vocal quantizer used in the system. It’s the work of [Jon D. Paul], who undertook the build to better understand how the SIGSALY system worked. [Jon] also wanted to honor the original builders, who developed a surprisingly sophisticated system given the technology of the day.

SIGSALY was seriously Top Secret in the day, and most of the documentation was destroyed when the system was decommissioned. Working from scant information, [Jon] was able to recreate the quantizer from period parts, including five vintage VT-109/2051 thyratrons scrounged from eBay. The vacuum tubes are similar in operation to silicon-controlled rectifiers (SCRs) and form the core of the ADC, along with a resistor divider ladder network. Almost every component is period correct, and everything is housed in a nice acrylic case. It’s a beautiful piece of work and a great homage to a nearly forgotten piece of cryptographic history.

Interestingly, Bell Labs had a bit of a head start on the technology that went into SIGSALY, by virtue of their work on the first voice synthesizer in the 1930s.

Continue reading “Rebuilding The First Vocal Encryption System” →

The Voice Of Dave, Now In Toy Form

January 26, 2019 by 13 Comments

Dave Jones is something of a celebrity in the hacker and maker communities, bringing his considerable knowledge and experience to bear on a wide variety of electronic and engineering topics. His unique voice and candor have endeared him to many, and he’s one of the more quotable YouTubers currently on the scene. With that in mind, [Andrei Aldea] decided to build a Speak ‘n’ Say in his honor.

The build was inspired by an earlier effort by [Ben Heck]. [Andrei] started by disassembling the Speak ‘n’ Say, and determined that there was a simple button matrix that would allow the toy’s position to be read easily. These buttons were wired into an Arduino Nano, which then reads an SD card and plays sound samples using the MP3 Module from DFR Robot.

[Andrei] made sure the toy was replete with custom graphics, which complete the look. Additionally, each Dave quote on the board has a series of soundbites, chosen randomly by the Arduino, giving a little more variety than the original toy.

It’s a fun build, and we’d love to see a version with line-out or some bigger speakers to blast the Gospel of Dave at a truly impressive volume. We’ve seen other speaking Arduinos, too – like this imposing HAL build. Video after the break.

Continue reading “The Voice Of Dave, Now In Toy Form” →

WiFi Controlled Finger

WiFi Controlled Finger Dims Lights Over UDP

January 26, 2019 by 10 Comments

While WiFi controlled lights are readily available, replacing your lighting fixtures or switches isn’t always an option. [Thomas] ran into this issue with his office lights. For the developers in the office, these lights always seemed to run a little too bright. The solution? A 3D printed, WiFi controlled finger to poke the dimmer switch.

This little hack consists of a servo, a 3D printed arm and finger assembly, and a Wemos D1 Mini development board. The Wemos is a low cost, Arduino compatible development board based on the ESP8266. We’ve seen it used for a wide variety of hacks here on Hackaday.

For this device, the Wemos is used to listen for UDP packets on the company’s WiFi network. When it receives a packet, it tells the servo to push the dimming button for a specified amount of time. [Thomas] wrote a Slack bot to automatically send these packets. Now, when the lights are too bright, a simple message to the bot allows anyone to dim the lights without ever leaving the comfort of their desk. Sure, it’s not the most secure or reliable method of controlling lights, but if something goes wrong, the user can always get up and flip the switch the old fashioned way.

Arduino And The Other Kind Of Homebrew

January 26, 2019 by 17 Comments

Usually, when we are talking about homebrew around here, we mean building your own equipment. However, most other people probably mean brewing beer, something that’s become increasingly popular as one goes from microbreweries to home kitchen breweries. People have been making beer for centuries so you can imagine it doesn’t take sophisticated equipment, but a little automation can go a long way to making it easier. When [LeapingLamb] made a batch using only a cooler, a stock pot, and a propane burner, he knew he had to do something better. That’s how Brew|LOGIC was born.

There are many ways to make beer, but Brew|LOGIC focuses on a single vessel process and [LeapingLamb] mentions that the system is akin to a sous vide cooker, keeping the contents of the pot at a specific temperature.

Honestly, though, we think he’s selling himself a bit short. The system has a remote application for control and is well-constructed. This isn’t just a temperature controller thrown into a pot. There’s also a pump for recirculation.

The common stock pot gets some serious modifications to hold the heating element and temperature probe. It also gets some spring-loaded clamps to hold the lid down. Expect to do a lot of drilling.

The electronics uses an Arduino, a Bluetooth board, and some relays (including a solid state relay). The finished system can brew between 5 and 15 gallons of beer at a time. While the system seems pretty good to us, he did list some ideas he has for future expansion, including valves, sensors for water level and specific gravity, and some software changes.

After reading that the system was similar to a sous vide cooker, we wondered if you could use a standard one. Turns out, you can. If you want to make better beer without electronic hacking, there’s always the genetic kind.