A Spreadsheet For The Python Hacker

September 23, 2022 by Al Williams 9 Comments

You can write a Python program or use a Jupyter Notebook to do almost anything. But you can also get a lot of things done quickly using a spreadsheet. Grist is a “hacker’s” spreadsheet that merges these worlds. It looks like a spreadsheet, but underneath are SQLite tables and the formula language is Python.

The code is open source and if you want it hosted, there are free and paid plans. You can even try it out without even logging in and either start with a blank screen or use a template. You can see an introductory video below.

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Simple Stopwatch with two buttons, an eight digit 7-segment display and ICSP programming cable going into the board

Add An OSHW Certified Stopwatch To Your Toolkit

September 23, 2022 by Abe Connelly 5 Comments

[MakingDevices] has created a simple stopwatch that makes for a nice introduction to surface mount electronic design and assembly. The project is open source hardware (OSHW) certified, with Gerbers, KiCAD files, and software all available.

Conceptually the stopwatch is straight forward, with a row of two four digit seven-segment displays being driven by a PIC18LF14k50 microcontroller through multiple NPN transistors. The PIC doesn’t quite have enough data lines to drive the two displays at once so an inverter is used to toggle between the two seven-segment blocks.

The circuit is continuously powered from a CR2032 coin cell battery. For normal usage with display, [MakingDevices] estimates 30+ hours of operation and 140+ hours without display, but still counting time. When idle, the “Extreme Low-Power (XLP)” capabilities of the PIC put the operating window estimates well beyond the self discharge of the coin cell battery. There’s an in circuit serial programming (ICSP) footprint that accepts a pogo pin TC2030-MCP-NL adapter for flashing the PIC.

Don’t let the simplicity fool you, this is a well documented project with detailed posts about the design, simulation and battery consumption. Various videos and glamour shots give a whole picture of the process, from design, assembly, testing to final validation.

It’d be wonderful to see the project extended or hacked on further, perhaps with a cute enclosure or case.

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For The ESP’s Next ESP Trick…

September 23, 2022 by Al Williams 10 Comments

It is a pretty stale dad joke to tell someone you have ESP when you mean you have an ESP8266 or ESP32 in your hand. However, [Naufil Metkar] uses an ESP device to pretend — via a magic trick — that he does have ESP. The trick requires a bit of 3D printing, an MPU6050 gyro sensor, and a lot of showmanship.

We hate to spoil an illusion, but you can probably figure it out from the list of things you need. The die has a gyro in it and uses a small ESP module to transmit its current orientation out to a display. There is a small reed switch that lets you turn off the device with a magnet. Without it, the battery dies quickly.

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Filament Cutter Uses Unusual (But Effective) 3D-Printed Spring Design

September 23, 2022 by Donald Papp 12 Comments

When one needs a spring, a 3D-printed version is maybe not one’s first choice. It might even be fair to say that printed springs are something one ends up making, rather than something one sets out to use. That might change once you try the spring design in [the_ress]’s 3D-printed filament cutter with printed springs.

The filament cutter works like this: filament is inserted into the device through one of the pairs of holes at the bottom. To cut the filment, one presses down on the plunger. This pushes a blade down to neatly cut the filament at an angle. The cutter is the device’s only non-printed part; a single segment from an 18 mm utility knife blade.

The springs are of particular interest, and don’t look quite like a typical spring. They take their design from this compliant linear motion mechanism documented on reprap.org, and resemble little parallel 4-bar linkages. These springs have limited travel, but are definitely springy enough for the job they need to do, and that’s the important part.

Want a more traditional coiled spring? Annealing filament wound around a mandrel can yield useful results, and don’t forget the fantastic mechanisms known as flexures; they have clear similarities to the springs [the_ress] used. You can see her design in action in the short video, embedded below.

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Big 3D Printed BMO Is Also An OctoPrint Server

September 23, 2022 by Lewin Day 7 Comments

OctoPrint is a useful tool for 3D printers, providing remote access to essentially every 3D printer with a USB port. [Allie Katz] decided to build an OctoPrint server in the shape of a life-sized BMO from Adventure Time, and the results are cute as heck.

A Raspberry Pi 4 is the heart of the build, with [Allie] selecting a 8 GB model for the job. It’s paired with a Raspberry Pi touchscreen that serves as BMO’s face. The Pi is also given a stereo audio output board, and hooked up to a custom PCB that runs all of BMO’s buttons. Printing BMO itself was fairly straightforward, but requires some experience working with larger PETG parts. A useful note for those playing along at home is that Polymaker PolyLite PETG in teal is just about a perfect dupe for BMO’s authentic body color.

A bit of Python code animates BMO’s face and delivers funny quips at the press of a button. When it’s time to work, though, the touchscreen serves as a straightforward interface for OctoPrint. The resulting build is both fun and functional, and a great example of what 3D printing really can achieve. It’s a cute figurine and a functional print all in one, something we don’t see everyday!

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Nazi Weapons Of The Future

September 23, 2022 by Al Williams 137 Comments

We know. The title sounds like a bad newsreel from 1942. Turns out, though, that the Nazis were really good at pouring money into military research and developing — or trying to develop — what they called “wunderwaffe” — wonder weapons. While we think of rockets and jets today as reasonably commonplace, they were state-of-the-art when Germany deployed them during WWII. While the rockets were reasonably successful, the jets were too few and too late to matter. However, those were just the tip of the iceberg. The German war industry had plenty of plans ranging from giant construction to secret weapons that seem to be out of the pages of a pulp science fiction magazine.

Size Matters

Part of the plans included huge ships including one aircraft carrier displacing 56,500 tons. Many of these were never completed and, in some cases, were never actually started. In contrast, the Essex-class USS Hornet displaces 31,300 tons and the Lexington was 37,000 tons. The H-class battleships would have had as much as 140,000 tons of displacement dwarfing the Yamato class (73,000 tons) and the Iowa class (53,000 tons).

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Hackaday Podcast 186: Weighing Cats, Slamming VU Meters, Slimmer Skimmers, And Clean Air On The Cheap

September 23, 2022 by Dan Maloney 2 Comments

Hackaday Editor-in-Chief Elliot Williams took time out from Supercon planning to join Staff Writer Dan Maloney for a look through the hacking week that was. We always try to keep things light, but it’s hard sometimes, especially when we have to talk about wars past and present and the ordnance they leave behind. It’s also not a lot of fun to talk about a continent-wide radio outage thanks to our angry Sun, nor is learning that a wafer-thin card skimmer could be lurking in your ATM machine.

But then again, we did manage to have some fun by weighing cats to make sure they’re properly fed, and making music by pegging VU meters. We also saw how to use PCBs to make a beautiful yet functional circuit sculpture, clean up indoor air on a budget, and move microns with hardware store parts. And we also got to celebrate a ray of international hope by looking back on the year that taught us much of what we know about the Earth.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download here!