Developing An Open Source Electronics Trainer

October 7, 2020 by Tom Nardi 25 Comments

It’s a safe bet that most Hackaday reader’s interest in electronics started at a young age, and that their early forays into the world of hardware hacking likely involved some form of “playground” kit. As long as you didn’t lose any of the components, these kits promised the user that hundreds of possible projects were just a few jumper wires away. Extra points awarded for when you decide to toss away the manual and fly solo.

While there’s still no shortage of such products on the market, [Josh Kittle] felt the concept could do with a freshening up. His open hardware “Microcontroller Trainer” harkens back to those old multi-kits, but adds in the sort of high-tech gadgetry that makes the modern DIY world go round.

It’s still got the traditional layout: a center mounted breadboard surrounded by an array of LEDs, a handful of buttons, and a pair of potentiometers. But there’s also sockets for the Raspberry Pi, ESP8266, ESP32, and Arduino. Plus a few of their most popular friends to keep them company: a .96″ OLED, 2.4″ Touch TFT, and a BC05 Bluetooth module.

Originally [Josh] created this design to help clean up his own workspace, figuring he could just put his most used components on a single compact board. But as you might expect, others expressed interest in the concept. Now he’s producing them as kits, and even working his way towards a third hardware revision that adds features such as an integrated 18650 battery for portable use.

While electronics kits that have you build a functional device are a great way to learn the ropes, we’re always glad to see fresh takes on the classic electronic “playground” concept.

Making A Modern Version Of A Steam Engine From Antiquity

October 6, 2020 by Dan Maloney 28 Comments

Imagine traveling back in time about 2,200 years, to when nothing moves faster than the speed at which muscle or wind can move it. Think about how mind-shattering it would have been to see something like Hero’s Engine, the first known example of a steam turbine. To see a sphere whizzing about trailing plumes of steam while flames licked around it would likely have been a nearly mystical experience.

Of course we can’t go back in time like that, but seeing a modern replica of Hero’s Engine built and tested probably isn’t too far from such an experience. The engine, also known as an aeolopile, was made by the crew over at [Make It Extreme], whose metalworking videos are always a treat to watch. The rotor of the engine, which is fabricated from a pair of hemispherical bowls welded together, is supported by pipes penetrating the lid of a large kettle. [Make It Extreme] took great pains to make the engine safe, with relief valves and a pressure gauge that the original couldn’t have included. The aeolopile has a great look and bears a strong resemblance to descriptions of the device that may or may not have actually been invented by Greek mathemetician [Heron of Alexandria], and as the video below shows, when it spins up it puts on a great show.

One can’t help but wonder how something like this was invented without someone — anyone — taking the next logical step. That it was treated only as a curiosity and didn’t kick off the industrial revolution two millennia early boggles the mind. And while we’ve seen far, far simpler versions of Hero’s Engine before, this one really takes the cake on metalworking prowess.

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A Good, Hard Look At Pre-Stressed Concrete

September 29, 2020 by Kristina Panos 43 Comments

From the looks of the average driveway or sidewalk, it may seem as though concrete is just destined to crack. But if concrete is so prone to cracking, how are we able to use it in so many high-stress applications like bridges and skyscrapers? This question came about while I was researching 3D-printed thermite for an article. Thermite is often used in welding railroad tracks, and I linked a video of fresh tracks being welded that had concrete ties. I knew I had to find out how concrete could be made to withstand the pressure of freight trains.

On its own, concrete is brittle and has no give to it at all. But that doesn’t mean it isn’t strong. Although concrete has good compression strength, the tensile strength is quite poor. Around the late 1800s, someone thought to fortify spans of concrete with steel reinforcing bars, better known as rebar. Steel can stretch, adding steel bars gives the concrete some tensile strength to go along with its compressive strength. Rebar also allows for thinner slabs and other members.

Rebar Only Goes So Far

Parking blocks are meant to be replaced occasionally. Image via Checkers Safety

Rebar or mesh-enforced concrete is good for things like parking lot blocks and roads, but it still fails before it ought to. In fact, it usually has to crack before the rebar can chip in any of its tensile strength.

In high-stress concrete applications like bridges and skyscrapers, it’s terrifically important to avoid deflection — that’s when a concrete member flexes and bends under load. Deflection can cause the modern glass skins to pop off of skyscrapers, among other problems.

A solid, rigid bridge is much nicer to walk, drive, and bicycle on than a bridge that sways in the breeze. But how do you do make a rigid bridge? One solution is to apply stresses to the concrete before it ever bears the load of cars and trucks or a steady schedule of freight trains.

Pre-stressed concrete is like rebar-enforced concrete, but with the added power of tension baked in. By adding stress to the concrete before it goes into service, deflection will be reduced or perhaps eliminated altogether. With the addition of tensile strength, more of the concrete’s own strength is able to come into play.

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Boot Sector Pong As A Crash Course In Assembly

September 28, 2020 by Tom Nardi 13 Comments

Have you ever wanted to develop a playable game small enough to fit into a disk’s 512 byte boot sector? How about watching somebody develop a program in assembly for nearly two hours? If you answered yes to either of those questions, or ideally both of them, you’re going to love this project from [Queso Fuego].

Whether you just want to check out the public domain source code or watch along as he literally starts from a blank file and codes every line for your viewing pleasure, chances are good that you’ll pick up a trick or two from this project. For example, he explains how all of the “graphics” in the game are done in 80 x 25 text mode simply by setting the background color of character cells without printing any text to them.

We really like the presentation in the video after the break, which was recorded over the course of multiple days, judging by the changing light levels in the background. As he types out each line of code, he explains what its function is and gives any background information necessary to explain how it will fit into the larger program. If you’ve ever wondered if you had what it takes to program in ASM, watching this video is a great way to decide.

[Queso Fuego] mentions that this project, and his research into this sort of low-level programming, came about due to the social distancing boredom that many of us are feeling. While we’re certainly not advocating for him to kept locked in his home permanently, with projects like this, you’ve got to admit it seems like a win for the rest of us.

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A Walking Robot With A Single Servo

September 16, 2020 by Kristina Panos 13 Comments

We’ve all been there — you see somebody do something cool on YouTube and you just have to give it a go. For [lonesoulsurfer], the drop-everything-and-build happened to be a little four-legged walker robot that runs on a single servo. Though it may be simple, there really is nothing like seeing a robot you created take its first steps.

[lonesoulsurfer]’s walker is made mostly from scrap aluminium and other scavenged parts like coat hangers, paper clips and the metal bits and bobs from banana jacks. The Dremeled and bent body would likely be the hardest to imitate for a first-time builder, but any sturdy chassis that allows for things screwed and bolted to it should work. Also, don’t expect it to work right away. It will take a bit of tuning to get the gait right, but it’s all part of the fun. So is modifying a 180° servo for continuous rotation.

We really like the way this robot walks — it saunters around like a long bulldog and looks like it can handle almost any terrain. Watch it walk after the break, and stick around for the build video.

There’s just something about simple robots without microcontrollers. If you’ve never heard of BEAM robots, cut your teeth on this ‘bot with circular legs.

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World Radio Lets Your Fingers Do The Walking

September 12, 2020 by Tom Nardi 9 Comments

Listening to radio from distant countries used to take a shortwave rig, but thanks to the Internet we can now pull in streams from all over the globe from the comfort of our own desktop. With a few clicks you can switch between your local news station and the latest in pop trends from Casablanca. But as convenient as online streaming might be, some folks still yearn for the traditional radio experience.

For those people, the Raspberry Pi World Radio by [Abraham Martinez Gracia] might be the solution. Built into the body of a 1960s Invicta radio, this Internet radio uses a very unique interface. Rather than just picking from a list of channels, you use the knobs on the front to pan and zoom around a map of the world. Streaming channels are represented by bubbles located within their country of origin, so you’ll actually have to “travel” there to listen in. The video after the break gives a brief demonstration of how it works in practice.

We’ll admit it might become a bit tedious eventually, but from a visual standpoint, it’s absolutely fantastic. [Abraham] even gave the map an appropriately vintage look to better match the overall aesthetic. Normally we’d say using a Raspberry Pi 4 to drive a streaming radio player would be a bit overkill, but considering the GUI component used here, it’s probably the right choice.

Of course we’ve seen Internet radios built into vintage enclosures before, and we’ve even seen one that used a globe to select the station, but combining both of those concepts into one cohesive project is really quite an accomplishment.

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See This Casio? Watch It Unlock My Tesla!

September 4, 2020 by Kristina Panos 2 Comments

The whole point of gaining the remote unlock ability for our cars was to keep us from suffering the indignity of standing there in the rain, working a key into the lock while the groceries get soaked. [Mattia Dal Ben] reports that even Teslas get the blues and don’t unlock reliably all the time, in spite of the price tag.

[Mattia] decided that a spare key card might be good to have around, and that building it into his Casio F-91W watch would put the key as close at hand as it could be without getting an implant.

After programming a new J3A040-CL key card to match the car, getting the chip out was the easy part — just soak it in acetone until you can peel the layers apart. Then [Mattia] built a fresh antenna for it and wound it around the inside of a 3D printed back plate.

The hardest part seems to be the tuning the watch antenna to the resonant frequency expected by the car-side antenna. [Mattia] found that a lot of things mess with the resonant frequency — the watch PCB, casing, and even the tiny screws holding the thing together each threw it off a little bit.

Since the watch is less comfortable now, [Mattia] thought about making a new back from transparent resin, which sounds lovely to us. It looks as though the new plan is to move it to the front of the watch, with a resin window to show off the chip. That sounds pretty good, too. Check out the secret unlocking power after the break.

Casio watches are great, though we are more into the calculator models. Someone out there loves their F-91W so much that they made a giant wall clock version.

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