Pit Your Wits Against British Spooks

December 13, 2021 by Jenny List 13 Comments

The festive season is upon us, and for Brits of a technical bent that means it’s time for the GCHQ Christmas Challenge. Sent out annually as part of the Christmas card from the UK’s intelligence centre, this is a chance for would-be spooks to pit their wits against some of the nation’s cleverest cryptologists whose work you’ll never have heard of.

This year the puzzle is aimed at those with a secondary school education, in the hope of fostering an interest in maths and science in younger people. It’s a series of puzzles of ascending difficulty, but don’t be lulled into a false sense of security by the earlier ones being easy, to complete the set will still require some brain power.

We’re guessing that as in previous years, this puzzle will garner a significant quantity of entries. It’s a successful public relations exercise from the agency which like all such organisations has felt its fair share of controversy in its time. There may thus be readers who regard it with some suspicion, but it’s fair to say it’s not the only such popular exercise from a govenment agency. If meanwhile you fancy a bit of GCHQ history, we caught their Science Museum exhibition back in 2019.

Anr air quality sensor mounted on a bike's handlebar

Measuring Air Quality Using Mobile Sensors For The Masses

December 13, 2021 by Robin Kearey 8 Comments

Poor air quality is a major problem for city dwellers the world over. Dust, smoke, particles and noxious gases from vehicles, industry and agriculture makes many megacities downright hazardous to live in. Pinpointing the source of pollution and developing strategies for mitigation requires accurate data on pollutant levels, but obtaining these numbers is not always easy.

Enter CanAirIO, a citizen science project that aims to gather air quality data from around the world by putting sensors into the hands of as many people as possible. Its team has developed two different sensor nodes for this purpose: an indoor one that can measure CO₂, and a mobile one that can measure particulate matter (PM) levels. Both versions are powered by an ESP32 microcontroller that reads out the air quality sensors and connects to the Internet using WiFi or BlueTooth. The data can then be shared online to create detailed maps showing local variations in air quality.

The design of the sensor nodes is fully open-source, allowing anyone with basic electronic skills to build them. The sensors are a Sensirion SCD30 for CO₂ measurement and an SPS30 for PM levels. The mobile version comes with a neat 3D-printed enclosure that can be mounted on a bike’s handlebar, enabling the user to quickly gather data around their neighbourhood. A mobile app simplifies setting up the sensors and sharing the data.

The project has already been successful in gathering detailed data in the city of Bogotá, Colombia, and will no doubt prove useful in many other pollution hotspots around the world. We’ve seen similar community efforts to monitor air pollution and even radiation in various places, both showing how relatively simple devices can help to make a difference in people’s wellbeing. Continue reading “Measuring Air Quality Using Mobile Sensors For The Masses” →

Self balancing wheeled robot with auto-righting arms lofted high

A Self Righting Balancing Robot Configured The Easy Way

December 13, 2021 by Dave Rowntree 2 Comments

Norwegian electronics hacker [Hans Jørgen] aka [time expander] on YouTube, has a clear interest in robotics, and for his latest effort, decided that it was time to build a custom controller platform. Since [Hans] had a pile of Dynamixel servo motors lying around to test it with, a good first project for the platform was a simple self-balancing wheeled robot. (Video, embedded below)

We say ‘simple’ but that isn’t really the case, as there is a fair bit going on to get this to work. The first problem, is sensing, which was quickly solved with the excellent BMO055 IMU chip. Next, what to do when it falls over? Simply adding some servo-controlled arms, allowed the robot to flip itself back upright. Control is covered with a ESP32-WROOM-32D module from our friends at Espressif, which enables remote firmware uploading over the air (OTA update) as well as parameter tuning. In order to implement the latter, [Hans] chose to use bonjour/mDNS which is an implementation of zero-configuration networking. This gets the ESP32 onto the WiFi, but it isn’t immediately obvious how to connect to it, without a little digging around. To simply connection, [Hans] implemented a dynamic QR code via the connected OLED. This is just one of the those tiny 0.96″ displays that you see touted all over our corners of the internet.

Simply by scanning the QR code with any compatible device to hand brings up a simple configuration web page, allowing one to tweak the PID controller parameters, and get that balancing robot into check. Great stuff!

The PCB was designed in Eagle, firmware for the ESP32 is available, 3D models for the plastic are designed with fusion 360, and [Hans] is even currently working on some preliminary Alexa integration. What a fun project!

All the above, albeit an early cut (look out for bugs!) is available on the project GitHub for your viewing pleasure.

We’re no stranger to self-balancing 3D-printed bots, whilst you’re here, why not checkout A problematic Self-Balancing Sonic the Hedgehog? If wheeled bots aren’t your cup-of-tea, there’s a not-at-all freaky one-legged bouncing bot that may be of interest.

Continue reading “A Self Righting Balancing Robot Configured The Easy Way” →

An Open Source Detector For Identifying Plastics

December 13, 2021 by Tom Nardi 18 Comments

One of the challenges involved in recycling plastic is determining the specific type of plastic a given item is actually made of. To keep up with demand, large scale recycling centers rely on various automated systems to separate different types of plastic from a stream of incoming material. But in less technologically advanced parts of the world, workers can find themselves having to manually identify plastic objects; a time consuming and error-prone process.

To try and improve on the situation, [Jerry de Vos], [Armin Straller], and [Jure Vidmar] have been working on a handheld open hardware device that they refer to simply enough as the Plastic Scanner. The hope is that their pocket-sized unit could be used in the field to positively identify various types of plastic by measuring its reflectivity to infrared light. The device promises to be very easy to operate, as users simply need to bring the device close to a piece of plastic, push the button, and wait for the information to pop up on the OLED display.

Or at least, that’s the idea. While the team eventually hopes to release a kit to build your own handheld Plastic Scanner, it seems that the hardware isn’t quite ready for production. The most recent work appears to have been put in, not unexpectedly, the development board that lets the team refine their process. The development unit combines an array of IR LEDs with wavelengths ranging from 850 to 1650 nanometers, a InGaAs photodiode connected to an ADS1256 24-bit analog-to-digital converter (ADC), and an Arduino Uno. In comparison, the final hardware uses a Raspberry Pi Zero and a smaller “breakout board” that contains the sensor and IR LEDs.

Browsing through the software repository for the project, we can see the device uses Python, TensorFlow Lite, and a database of IR reflectivity values for known plastics to try and determine the closest match. Obviously the accuracy of such a system is going to be highly dependent on the quantity of known-good data, but at least for now, it appears the user is responsible for building up their own collection or IR values.

As interesting as this project is, we’re a bit skeptical about its purely optical approach to identifying plastics. Automated recycling centers do use infrared spectroscopy, but it’s only one tool of many that are employed. Without additional data points, such as the density or electrostatic properties of the plastic being tested, it seems like the Plastic Scanner would have a fairly high margin of error. Just taking into account the wide array of textures and colors the user is likely to encounter while using the device will be a considerable challenge.

Continue reading “An Open Source Detector For Identifying Plastics” →

USB LED Christmas Tree Is Making Spirits Bright

December 13, 2021 by Kristina Panos 9 Comments

[Piotr SB] knows there is no way out of the holidays; the only path is through. You’ve got to find cheer wherever and however you can, so why not cater to your own interests and build the cutest little LED Christmas tree you ever did see? And did we mention it’s USB and absolutely free (as in carols, not eggnog)?

This O-Christmas tree is made up of concentric rings that are built into a tier as you solder the LEDs. And of course you’re supposed use the LED legs as supports! One leg from each LED — 18 green and a red one for the top. Because the PCB is not quite thick enough, you’ll need to add a plastic spacer to get it to stay in the USB port. Not only is this a nice design, the snowflakes and snowman on the silkscreen totally seal the cuteness deal.

Ever get so frustrated with your Christmas tree that you want to just empty a few rounds into the thing? No? Well, you’d have a good reason to if you built this Duck Hunt ornament.

Ask Hackaday: Are Extruders The Only Feasible Tools For Toolchanging?

December 13, 2021 by Donald Papp 34 Comments

Toolchanging in 3D printers is no longer something from the bleeding edge; it’s going mainstream. E3D has a high-quality kit for a toolchanger and motion system, our own Joshua Vasquez has shared details about the open-source toolchanging Jubilee design, and just recently Prusa3D formally announced the Prusa XL, which promises toolchanging with up to five different extruders.

It’s safe to say toolchanging on 3D printers has stepped to the front, but what comes next? What kind of tools other than extruders make sense on a 3D printer?

First, let’s explain what makes separate extruders such fantastic tools. Being able to change extruders on-demand during a print enables things like true multi-material printing. Printing in more than one color or material will no longer be done by pushing different filaments through a single nozzle, which limits a print to materials that extrude under similar conditions and temperatures. Toolchanging means truly being able to print in multiple materials, even if they have different requirements, because each material has its own extruder. That’s a clear benefit, but what about tools other than extruders?

Continue reading “Ask Hackaday: Are Extruders The Only Feasible Tools For Toolchanging?” →

Design For Test Hack Chat

December 13, 2021 by Dan Maloney 3 Comments

Join us on Wednesday, December 15 at noon Pacific for the Design for Test Hack Chat with Duncan Lowder!

If your project is at the breadboard phase, or even if you’ve moved to a PCB prototype, it’s pretty easy to know if it works. It either does what it’s supposed to do, or it doesn’t, and a few informal tests will probably tell you all you need to know. But once you scale up to production, the testing picture becomes quite different. How do you know you’re not shipping out a problem? And how do you make sure your testing process doesn’t become a bottleneck?

Answering questions like these can be difficult, which is why we’ve invited Duncan Lowder to come talk with us. He was a test lead at places like Glowforge and Sphero before founding FixturFab, where he’s working on ways to make hardware testing as easy as possible, no matter what scale you’re working at. We’ll learn all about how to make our designs easy to test right from the get-go and take the pain out of that bed of nails.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, December 15 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.