Hackaday Prize 2023: PAROL6 – A GPL Desktop Robotic Arm

August 15, 2023 by 8 Comments

Parol 6 is a 3D-printed six-axis robot arm created by [Petar Crnjak] as a combination of the principles from a few previous projects. Aside from a pneumatic gripper, each axis is driven by a stepper motor, with at least a few of these axes being driven through a metal planetary gearbox for extra precision and torque.

From what we can glean from the work-in-progress documentation, there are some belt drives on four of the relevant axes and a mix of NEMA17 format steppers driving either 20:1 or 10:1 reduction boxes. There appears to be a mix of inductive sensors and traditional microswitches used, but it’s not so easy to work out where these are placed. Continue reading “Hackaday Prize 2023: PAROL6 – A GPL Desktop Robotic Arm” →

Mobile phone reading an NFC tag with information on a garden plant

NFC Puts A Stake In The Ground

August 15, 2023 by 21 Comments

Sometimes we have a new part or piece of tech that we want to use, and it feels like a solution looking for a problem. Upon first encountering NFC Tags, [nalanj] was looking for an application and thought they might make a great update to old-fashioned plant markers in a garden. Those are usually small and, being outside 24/7, the elements tend to wear away at what little information they hold.

traditional plant marker

[nalanj] used a freeform data structuring service called Cardinal to set up text information fields for each plant and even photos. Once a template has been created, every entry gets a unique URL that’s perfect for writing to an NFC tag. See the blog post on Cardinal’s site for the whole process, the thought behind the physical design of the NFC tag holder, and a great application of a pause in the 3D print to encapsulate the tags.

NFC tags are super hackable, though, so you don’t have to limit yourself to lookups in a plant database. Heck, you could throw away your door keys.

Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The QWERTY Drum Set

August 15, 2023 by 1 Comment

What does portability in a keyboard mean to you? For Hackaday’s own [Brian McEvoy], the image evokes that quintessential 80s instrument, the keytar.

But those left-hand keys aren’t just for show — they’re macro keys. It runs on an Adafruit Feather 32u4 Bluefruit, so [Brian] can forego the cord and rock out all over the room.

I love the construction of this keyboard, which you can plainly see from the side. It’s made up of extruded aluminum bars and 2 mm plywood, which is stacked up in layers and separated with little wooden donuts acting as spacers. Unfortunately, [Brian] accidentally made wiring much harder by putting the key switches and the microcontroller on different planes.

Although you could theoretically use any key switches for this build, [Brian] chose my personal and polarizing favorite, browns. If you’re going to use a travel keyboard, you’re probably going to be around people, so blues are probably not the best choice. With browns, you kind of have yourself a middle ground, best-of-both-worlds thing going on. The keycaps are among the best parts of this build, and it seems [Brian] chose them because the legends are on the sides, which makes it much easier to type on while wearing it. Kismet!

Continue reading “Keebin’ With Kristina: The One With The QWERTY Drum Set” →

UChaser Follows You Anywhere

August 15, 2023 by 16 Comments

If you’ve been making up for lost years of travel in 2023, you might have seen a fellow traveler in the airport terminal or train station walking with their luggage happily careening behind them. [Jesse R] and [Brian Lindahl] wanted more of that. They wanted an open-source, low-cost system that could be put in anything.

The basic principle is that they will have a transmitter that sends both a radio signal and an ultrasonic pulse. The receiver receives the radio signal and uses it as a reference for the two ultrasonic sensors. The time since the radio signal is compared between the two, and a distance and direction are established.

In practice, the radio is an ESP32-S3 using ESP-NOW (which we’ve seen relatively recently on another project), a protocol from Espressif that offers low latency 250 bytes payloads. The ultrasonic transceiver is based on Sparkfun’s HC-SR04. For prototyping purposes on the receiver, they just removed the transmitter to avoid populating the airwaves, as to listen, you had to transmit. The prototype was an electric wheelbarrow that would happily follow you around the yard wherever you go.

With the concept validated, they moved to a custom ultrasonic setup with a custom buffer amp and damp transistor, all centered around 20kHz. The simulations suggested they should have been better than the HC-SR04 from Sparkfun, but the 30-foot (9 meters) range went to 10 feet (3 meters). They ultimately returned to using Sparkfun’s circuit rather than the custom amp.

We’re looking forward to seeing the project continue. There are various challenges, such as variability in the speed of sound, echos and reflections, and ultrasonic line of sight. We love the peak behind the curtain that allows us to see what decisions get made and the data that informs those decisions. All the code and PCB design files are available on GitHub under an MIT and Creative Common license, respectively. This project was submitted as part of the 2o23 Hackaday Prize.

Video after the break.

The HackadayPrize 2023 is Sponsored by:

Continue reading “UChaser Follows You Anywhere” →

Screwdrivers And Nuclear Safety: The Demon Core

August 15, 2023 by 61 Comments

Harry Daghlian and Louis Slotin were two of many people who worked on the Manhattan Project. They might not be household names, but we believe they are the poster children for safety procedures. And not in a good way.

Harry Daghlian (CC-BY-SA 3.0, Arnold Dion)

Slotin assembled the core of the “Gadget” — the plutonium test device at the Trinity test in 1945. He was no stranger to working in a lab with nuclear materials. It stands to reason that if you are making something as dangerous as a nuclear bomb, it is probably hazardous work. But you probably get used to it, like some of us get used to working around high voltage or deadly chemicals.

Making nuclear material is hard and even more so back then. But the Project had made a third plutonium core — one was detonated at Trinity, the other over Nagasaki, and the final core was meant to go into a proposed second bomb that was not produced.

The cores were two hemispheres of plutonium and gallium. The gallium allowed the material to be hot-pressed into spherical shapes. Unlike the first two cores, however, the third one — one that would later earn the nickname “the demon core” — had a ring around the flat surfaces to contain nuclear flux during implosion. The spheres are not terribly dangerous unless they become supercritical, which would lead to a prompt critical event. Then, they would release large amounts of neutrons. The bombs, for example, would force the two halves together violently. You could also add more nuclear material or reflect neutrons back into the material.

Continue reading “Screwdrivers And Nuclear Safety: The Demon Core” →

Automation For The NES

August 15, 2023 by 11 Comments

Old hardware might not be anywhere close to as powerful as modern technology, but it does have a few perks. Aesthetics can of course drive the popularity of things like retro gaming systems, but the ease of understanding the underpinnings of their inner workings is also critical. The Nintendo Entertainment System, now nearly four decades old, is a relatively simple machine by modern standards and this lends the system to plenty of modifications, like this controller that allows the system to be somewhat automated.

The original NES controller used a fairly simple shift register to send button presses to the system. The system outputted a latch signal to the controller, the shift register would take as input the current state of the buttons, and then would send them one-by-one to the system at a rate of around 1000 times per second. These signals can be sent without a controller easily enough, too. This build uses a CD4021 shift register, which is the same as the original controller, but instead of reading button states it accepts its inputs from a separate computer via a latching circuit. In this case, the separate computer is a custom design that came about through adapting cassette storage for a 6502-based computer, but it could come from anything else just as easily.

With this system in place, it’s possible to automate gameplay to some extent. Since the system can’t get feedback about the game in its current state, it requires some precise timing to get it to play the game well, and a lot of tuning needs to go into it. This isn’t just a one-off, either. Similar methods are how we get tool-assisted speedruns of games and although these are often done in emulators instead of on real hardware, they can result in some interesting exploits.

Continue reading “Automation For The NES” →

Low Res Arduino Thermal Camera

August 15, 2023 by 10 Comments

Do you know how you see those cheap telescopes at the department store? The box has beautiful pictures that probably came from the Hubble. What you will see is somewhat different. You have to carefully look at [upir’s] Arduino thermal camera project because it intersperses pictures of what you expect an 8×8 sensor will produce with images produced by a much better camera.

The actual project — watch the video below — is undoubtedly neat. An inexpensive 8×8 IR sensor and an 8X8 LED panel join to form a crude but usable thermal camera.

Continue reading “Low Res Arduino Thermal Camera” →