The completed oscilloscope in parts, with the screen in the front connected with prototyping wires, protoboarded buttons on the right, and the BlackPill board somewhere behind

DIY STM32 Scope Is Simple, Cheap, And Featureful

February 27, 2023 by Arya Voronova 28 Comments

Would you like to have a small digital oscilloscope? Do you have a spare BlackPill (STM32F401) board and a TFT display laying around? [tvvlad1234] presents us with a simple and educational digital storage oscilloscope design that barely needs any components for you to build one, and it’s packed with features just like you would expect from a self-respecting open-source project. Not just that — it can even stream data to your computer, in a format compatible with the TekScope software!

It’s hard to overshadow just how easy this scope is to build, use, and hack on. You really don’t need much in the way of parts, a protoboard will do, though you can also etch or order your own PCBs. The front-end is super straightforward to find components for and assemble, a few opamps and resistors is all you need. So after jumper-wiring the LCD and three push buttons to your BlackPill, you’re golden.

Of course, the simple frontend results in the input range being from -3.3 V to 3.3 V, but as you could guess, this is exactly the kind of project where you could tweak the resistors and even upgrade it later on. Are you a bit lost in how oscilloscopes work? [tvvlad1234] has an explainer for you, too!

This build could easily take up a honorary “temporary turned permanent” place on your bench, thanks to its McGyver-esque qualities. It’s also, quite possibly, a better scope than the red “soldering kit” ones we’ve seen online. All in all, it’s a strong contender in the “simple and powerful DIY scope” arena, before this, we’ve seen one built with an Arduino Nano, and one with a Pi Pico.

The sensor hub in all its glory, sensor itself on top, standing on 3D-printed feet, and the PCB on the bottom

Hacker-Friendly And Elegant Air Quality Sensor Hub

February 27, 2023 by Arya Voronova 9 Comments

Ever wanted an indoor environment sensor that’s dead simple yet a complete package? That’s the anotter-sensor-hub project from [Jana Marie], designed for the Sensirion SEN05x series sensors, with a SEN055 sensor shown in the picture above. Given such a sensor, you can measure VOCs and NOCs (Volatile and Non-Volatile Organic Compounds), as well as PM1, PM2.5, PM4 and PM10 particulate matter indices, with temperature and humidity sensing thrown in for good measure. Fully open and coupled with 3D printable stand files, this alone makes for an air quality hub fit for a hacker’s desk. That’s not all, however — this board’s elegant extensibility is a good match for the sensor’s impressive capabilities!

The PCB itself might look simple, it’s simply an ESP32 and some supporting circuitry required. But you’ll notice there’s also a trove of connector footprints for different interfaces; whatever else you might want to add to your sensor hub, whether it connects through I2C, SPI or PWM, you can! As usual, the sensor itself is the most expensive part of such a project — the boards themselves are around $5 USD apiece fully assembled, but one sensor-included hub will set you back roughly $42 USD. That said, it’s a great value for the price, and the trove of sensing data you can get might just more than pay for itself in quality-of-life improvements you make. Of course, everything is open-source and comes as a complete packages for you to start using. The firmware, KiCad files, 3D holder and even Grafana dashboard files can be found on GitHub.

Such air quality sensor platforms have been getting more and more popular, and hackers have been paying attention. Having a full open-source package like this at our disposal is amazing. If you’re looking for a cheaper “baby’s first air quality sensor”, drop by your local IKEA — there’s a way less featureful but quite cheap sensor that you can equip with an ESP8266, perhaps, even on a custom PCB.

OpenStructures Is A Modular Building System For The RepRap Age

February 21, 2023 by Navarre Bartz 24 Comments

Modular construction toys like LEGO and Meccano are great for prototyping, but they aren’t so great for large builds. OpenStructures promises to be a modular building system for projects large and small.

Originally conceived in 2007 by [Thomas Lommée], OpenStructures is a modern, more robust reinterpretation of Grid Beam, which was itself a reinterpretation of the earlier Living Structures. By using a common standard (PDF), parts can be reused project after project as they would with LEGO, meaning you can spend more time building and less time cutting or figuring out joints. OpenStructures parts need connection points, part diameters, or part dimensions at multiples of 20 mm to be compatible. To fulfill the spirit of the project, parts should be designed for disassembly, use recyclable materials when possible, and be Open Source.

The system seems like a great starting point for prototyping furniture or other large builds more quickly than building everything on a case-by-case basis. By including diameters for round objects as well as square and rectangular profiles, OpenStructures is a more flexible (and aesthetically pleasing?) option than Grid Beam.

A couple more options for furniture-scale modular construction are these big LEGO bricks or copper pipe.

(via Low Tech Magazine)

A wooden box sits on a darker wooden table. The box has a red, glowing number 8 on it.

Ambient Display Tells You If Borealis Is Coming To Town

January 29, 2023 by Navarre Bartz 8 Comments

For those times when you’d rather not get sucked down another internet rabbit hole when you really just wanted the weather, an ambient display can be great. [AlexanderK106] built a simple ambient display to know the probability the Northern Lights would visit his town.

Starting with a NodeMCU featuring the ESP8266, [AlexanderK106] walks us through a beginner-friendly tutorial on how to do everything from configure the Arduino IDE, the basics of using a breadboard. finding a data source and parsing it, and finally sticking everything into an enclosure.

The 7-segment display is taped and set into the back of the 1/4″ pine with enough brightness to shine through the additional layer of veneer on top. The display is set to show one digit and then the next before a three second repeat. A second display would probably make this easier to use day-to-day, but we appreciate him keeping it simple for this tutorial.

Looking for more ambient displays? Checkout the Tempescope or this clock that lets you feel the temperature outside!

All About USB-C: High-Speed Interfaces

January 17, 2023 by Arya Voronova 40 Comments

One amazing thing about USB-C is its high-speed capabilities. The pinout gives you four high-speed differential pairs and a few more lower-speed pairs, which let you pump giant amounts of data through a connector smaller than a cent coin. Not all devices take advantage of this capability, and they’re not required to – USB-C is designed to be accessible for every portable device under the sun. When you have a device with high-speed needs exposed through USB-C, however, it’s glorious just how much USB-C can give you, and how well it can work.

The ability to get a high-speed interface out of USB-C is called an Alternate Mode, “altmode” for short. The three altmodes you can encounter nowadays are USB3, DisplayPort and Thunderbolt, there’s a few that have faded into obscurity like HDMI and VirtualLink, and some are up and coming like USB4. Most altmodes require digital USB-C communication, using a certain kind of messages over the PD channel. That said, not all of them do – the USB3 is the simplest one. Let’s go through what makes an altmode tick. Continue reading “All About USB-C: High-Speed Interfaces” →

Impressive Sawdust Briquette Machine

January 16, 2023 by Anool Mahidharia 28 Comments

When you are a life long carpenter with an amazing workshop, you’re going to make a lot of saw dust, and managing its collection and storage poses quite a challenge. [Russ] from [New Yorkshire Workshop] built an impressive Briquette press to handle the problem.

It’s a hydraulic press that ingests saw dust and spits out compressed briquettes ready for fueling his rocket mass heater. The build starts with a batch of custom, laser cut steel parts received from Fractory. The heart of the machine is a 300 mm stroke hydraulic cylinder with a beefy 40 mm rod. The cylinder had to be taken apart so that the laser cut mounting flanges could be welded, slowly so as not to deform the cylinder. The intake feed tube was cut from a piece of 40 mm bore seamless tube. A window was cut in the feed tube and funnel parts were welded to this cutout. The feed tube assembly is then finished off with a pair of mounting flanges. The feed tube assembly is in turn welded to the main feed plate which will form the base of the saw dust container. The hydraulic cylinder assembly is mated to the feed tube assembly using a set of massive M10 high tensile class 10.9 threaded rods. The push rod is a length of 40 mm diameter mild steel bar stock, coupled to the hydraulic cylinder using a fabricated coupling clamp. On the coupling clamp, he welded another bracket on which a bolt can be screwed on. This bolt helps activate the limit switches that control the movement of the hydraulic cylinder and the feed motor. Continue reading “Impressive Sawdust Briquette Machine” →

Blinky Business Card Plays Snake And Connect Four

January 16, 2023 by Anool Mahidharia 6 Comments

There’s no better way to introduce yourself than handing over a blinky PCB business card and challenging the recipient to a game of Connect Four. And if [Dennis Kaandorp] turns up early for a meeting, he can keep himself busy playing the ever popular game of Snake on his PCB business card.

Quite wisely, [Dennis] kept his design simple, and avoided the temptation of feature creep. His requirements were to create a minimalist, credit card sized design, with his contact details printed on the silk legend, and some blinky LED’s.

The tallest component on such a design is usually the battery holder, and he could not find one that was low-profile and cheap. Drawing inspiration from The Art of Blinky Business Cards, he used the 0.8 mm thin PCB itself as the battery holder by means of flexible arms.

Connect-Four is a two player game similar to tic-tac-toe, but played on a grid seven columns across and six rows high. This meant using 42 dual-colour LED’s, which would require a large number of GPIO pins on the micro-controller. Using a clever combination of matrix and charlieplexing techniques, he was able to reduce the GPIO count down to 13 pins, while still managing to keep the track layout simple.

It also took him some extra effort to locate dual colour, red / green LED’s with a sufficiently low forward voltage drop that could work off the reduced output resulting from the use of charlieplexing. At the heart of the business card is an ATtiny1616 micro-controller that offers enough GPIO pins for the LED matrix as well as the four push button switches.

His first batch of prototypes have given him a good insight on the pricing and revealed several deficiencies that he can improve upon the next time around. [Dennis] has shared KiCad schematic and PCB layout files for anyone looking to get inspired to design their own PCB business cards.

Continue reading “Blinky Business Card Plays Snake And Connect Four” →