Segments light up as a person's step goal is achieved.

Slither: A Visual Pedometer That Sheds Light

January 7, 2022 by Kristina Panos No comments

Have you already broken that New Year’s resolution to get more exercise? Yeah, us too. Maybe the problem is simply that we didn’t gamify the goal. A simple visual aid that shows your progress can help make a goal more achievable and easier to stick to, day after January day. That’s the idea behind [skhackett]’s Slither, the visual pedometer.

Although Slither uses the Fit Bit app, no actual Fit Bit is required — great news for those of us who don’t like to wear accessories. But you will have to carry your phone everywhere if you want your steps to count. By tracking the steps taken each day, the sum of Slither’s segments signifies a weekly total goal of 50,000 steps.

Around back is a Feather Huzzah that receives step data from the phone and drives a strand of side-lit LED strips. There’s a Hall effect sensor in the tail, and Slither is powered on and off with a small, separate piece of wood and acrylic with a magnet embedded inside. Isn’t that a classy way to switch a snake?

We really like the look of the plywood here, though [skhackett] recommends using MDF instead because they experienced a fair amount of chipping. If you just want to watch the snake light up, it shouldn’t be too hard to cheat the pedometer.

HDD Vending Machine Works Like A Vending Machine Should

December 19, 2021 by Arya Voronova 48 Comments

The concept of vending machines in hackerspaces is nothing new, but [iooner] took it a step further – as hackers ought to. Putting HDDs into the rotating spring of a repurposed vending machine, right where you’d expect to see a Granola bar, isn’t revolutionary – but we don’t remember anybody doing it before this. And, with how heavy a typical HDD is, you are guaranteed to never encounter the “it just won’t fall down” issue that’s omnipresent with the snack-loaded machines.

Nothing could illustrate the premise of this concept better than [iooner]’s video does, and hackerspaces acquiring and having fun with consumer-facing equipment is always fun to watch. A stereotypical hackerspace vending machine sells resistor packs and Arduino boards, but you wouldn’t see it venture into the realm of data storage and distribution. Given how cheap HDDs are nowadays, this concept could benefit us in a variety of applications – selling new HDDs to members for regular data storage use, or distributing hacking magazine archives and Wikipedia dumps, even exclusive release things like recordings of hackerspace lectures.

If this looks familiar, we’ve reviewed a conceptually similar vending machine five years ago, and quite a few DIY ones. If software piracy is more of your thing, there are likely ways to get HDDs out of vending machines without paying, using either robots or an NFC-enabled phone. And, if you’re going to reuse a vending machine, a primer on reverse-engineering its internal comms bus could be of help.

Continue reading “HDD Vending Machine Works Like A Vending Machine Should” →

Fabulous Flexure Mechanism Makes For Resetting Cat Calendar

December 14, 2021 by Kristina Panos 18 Comments

When we met [Amy Makes Stuff] at the 2019 Hackaday Superconference, we were immediately impressed with the array of flexure mechanisms displayed on a board hanging around her neck. That must be where we saw [Amy]’s original version of the cat calendar — a simple way to know for sure whether the shared house’s cat has been fed once, twice, or not at all on a given day.

Left: a simple flexure that gets heavily stressed when actuated. Right: a slightly more complicated flexure that uses less force.

Awesome as it is, the flexure mechanism doesn’t reset the yes/no indicators when the day clicks over — that has to be done manually. So when [Amy] was offered to try a small desktop CNC, she decided it was time to make a new version that resets automatically. Check it out in the video after the break, which also includes an exploration of [Amy]’s choice of flexure design as well as a bonus review of the CNC.

This is just an all-around great video, especially after [Amy] neglected to mill out the check marks and circles, sending her down a rabbit hole of attempting to make branding bits for these that could be chucked into a soldering iron. Unfortunately, the mill stops short of having the necessary mettle for milling metal.

Although [Amy] is likely known for her flexures, she has a ton of skills. Remember when she resurrected that burned and bubbled laser cutter? Or the time she machined a honing jig for hand-sharpening chisels and planes?

Continue reading “Fabulous Flexure Mechanism Makes For Resetting Cat Calendar” →

Complete Hobo Stove Cooking System Could Get You Through The Apocalypse

December 7, 2021 by Kristina Panos 70 Comments

Let’s face it, times are hard, and winter is imminent in the northern hemisphere. No matter how much you have to your name, there’s nothing like a cup of hot tea or a warm meal on a cold day. So if you need a snow day activity, consider preparing for whatever may come to pass by building yourself a complete hobo stove system out of empty cans.

[ElectroIntellect]’s stove consists of a 20oz can turned upside down with several holes made in the bottom for heat to rise. The smaller cans are used for cooking pots, and the smallest as a cup. The stove itself is meant to run on flaming twigs stuffed into the base, or a couple of tealight candles if you can only find green wood around.

This comprehensive guide covers everything from building the system to packing it up safely and taking it out to cook in the concrete wilderness. As a special bonus, [ElectroIntellect] brews up some hobo coffee on the stove using an old (clean) sock, and prepares a can of chili in under an hour with candle power.

Too much hardware for you? You can make a disposable rocket stove out of wood.

Vision Impaired Electronics Engineer Shows The Way To Get Things Done

November 26, 2021 by Ryan Flowers 18 Comments

A funny thing happens as the average electronics hobbyist gets older: Their eyes- well they just don’t work the same as they used to. But what if your life started out with compromised vision? In this epic forum post (Google translated from Polish to English), we meet nearly blind hacker [Urgon]. He goes into great detail about his condition and how it affects not just his daily life, but also his abilities as an electronics engineer. Or conversely, how it doesn’t.

[Urgon]’s origin story is familiar. At eight years old, he disassembled his first television. His self-education continued by using his remaining vision to soak up every bit of literature about electronics that he could get his hands on. A well-intentioned but protective mother kept him away from soldering irons, fearing that the close proximity to his good eye might not bode well for his remaining vision.

If Urgon can solder 0805's, so can you! — If Urgon can solder SOIC’s 0805’s, so can you!

Despite a failed eye, and his other having quite severe glaucoma, [Urgon] has persevered. He uses assistive technologies as you’d expect, but notes that in more recent times some excellent free software has surpassed some of the commercial products he used in the past.

While even the sighted among us often shy away from SMD components, [Urgon] dives right in. SOIC packages and 0805 parts don’t hold him back. Bright LED flashlights, zooming in with his smart phone, and surely a healthy dose of patience make his hackery possible.

That’s not to say that [Urgon] hasn’t had some noteworthy incidents. He’s suffered electric shock from the 400 V capacitors in an ATX PSU, burned his face with his soldering iron, and even managed to step on a DIP package. Barefoot. Yes, the pins were facing up.

But wait- there’s more! In this follow-up post, [Urgon] discusses more assistive/adaptive technologies and how hackers like you and I can focus our efforts on things the vision impaired will find most helpful.

Our hats are off to [Urgon] and those like him who persevere despite the odds. We can all learn from [Urgon]’s hacker spirit and his dedication to the craft. We recently covered some blind software hackers who have taken it upon themselves to fly passenger jets– virtually, of course!

Thanks to [Moryc] for the excellent tip!

Find Your Way In The Starry Skies With DobsonianDSC

November 25, 2021 by Maya Posch 13 Comments

An obvious problem with the use of a telescope is getting the former to point at the proper part of the sky which you intend to observe, or vice versa when you spot something interesting and wish to record the exact location. While all of this can be done manually with some trouble, there’s a lot to be said for automating this process. Unfortunately these Digital Setting Circles (DSC) features are not cheap even as add-on, which is why [Vladimir Atehortúa] created DobsonianDSC as a low-cost DIY solution.

As the name suggests, this project is based around a Dobsonian-style telescope: Newtonian tube with simple altazimuth base. Aside from the mechanical construction, this system uses an ESP32 as its controller along with two rotary encoders, with the simple circuit detailed in a build guide. The firmware for the ESP32 is written in the Arduino C dialect, and a guide for flashing the ESP32 with the Arduino IDE and connecting it to the WLAN is provided as well.

After setup, the resulting telescope system can be used either via WiFi or Bluetooth from existing apps such as SkySafari that support the ‘Basic Encoding System’. An initial calibration is required, but after that you should have a telescope that works in concert with SkySafari or similar to automate this tedious part of astronomy away.

Obviously this is not a ready-to-install system, as every telescope is shaped and sized differently, but inspiration for mounting solutions is provided as well.

‘Tiny Wake-Up Light Is Hugely Bright

November 6, 2021 by Kristina Panos 26 Comments

Let’s face it — waking up is rough no matter what time of year it is. But the darkness of fall and winter makes it so much worse. In the past, [Maarten] has used music with increasing volume, but depending on the setup, it can be dodgy if you want to hear a different song each day and don’t have all your files volume-leveled.

Wake Up Bright is the latest in a line of wake-up widgets [Maarten] has made to help rouse them in the morning. Their write-up covers all ideas they’ve had on the subject over the years, as well as the electronics, firmware, debugging, and all the upgrades made after using it for awhile.

Slowly brightening an LED doesn’t have to be difficult or expensive. [Maarten] originally used an Atmel 90S2313 AVR and later upgraded to an ATtiny 2313, which was easy because the two are pin-compatible. The 2313 outputs PWM, which duty-cycles the LED to create a nice fade-in of white light that is way more gentle than that classic 1980s alarm clock buzz-beep.

Over time, this project went from one IKEA enclosure to another. We really like the newer one, which looks like it was designed for people to hack into a wake-up light.

Our eyes perceive brightness increases logarithmically, but PWM is linear. We can get around this by multiplying the PWM value by some factor every so often, but the problem is that this AVR never learned its multiplication tables. So how, then? [Maarten]’s answer is byte shifting using a 16-bit register — one byte for PWM, and the other as a scratch pad to do logarithmic math. [Maarten] multiplies the 16-bit register by 1/256 every couple of seconds, which results in a logarithmic increase of brightness. It’s calculated for a 15-minute sunrise, which required some experimentation to get right.

Whereas [Maarten] started with a 3 W RGB LED, the current version has three 10 W LEDs and uses a power supply from an old monitor. Daylight Saving Time is coming to an end in the US, and it’s gonna get worse quickly. Lucky for you, this project is completely open source down to the firmware.

You think that 1980s alarm clock buzz-beep is bad? How about some repeated slaps to the face to wake up?