A Coin Cell Powers This Tiny ESP32 Dev Board

February 22, 2019 by 27 Comments

Just for the challenge, just for fun, just for bragging rights, and just to do a little showing off – all perfectly valid reasons to take on a project. It seems like one or more of those are behind this tiny ESP32 board that’s barely larger than the coin cell that powers it.

From the video below, [Mike Rankin] has been working down the scale in terms of powering and sizing his ESP32 builds. He recently completed a project with an ESP32 Pico D4 and an OLED display that fits exactly on an AA battery holder, which he populated with a rechargeable 14550. Not satisfied with that form factor, he designed another board, this time barely larger than the LIR2450 rechargeable coin cell in its battery holder. In addition to the Pico D4, the board sports a USB charging and programming socket, a low drop-out (LDO) voltage regulator, an accelerometer, a tiny RGB LED, and a 96×16 OLED display. Rather than claim real estate for switches, [Mike] chose to add a pair of pads to the back of the board and use them as capacitive touch sensors. We found that bit very clever.

Sadly, the board doesn’t do much – yet – but that doesn’t mean we’re not impressed. And [Mike]’s no stranger to miniaturization projects, of course; last year’s Open Hardware Summit badge was his brainchild.

Continue reading “A Coin Cell Powers This Tiny ESP32 Dev Board” →

Building An Optically Pumped Laser Pointer

February 22, 2019 by 25 Comments

As a society, we’ve largely come together to agree that laser pointers are mostly useless. They’re now the preserve of university lecturers and those destined to wind up in a jail cell for harassing helicopter pilots. Most pointers are of the diode-pumped solid state variety. However, [Zenodilodon] treads a different path.

The laser cavity glows in operation, though it’s probably inadvisable to look directly at it.

Instead of the usual DPSS build, this pointer packs an optically pumped semiconductor laser, or OPSL. These lasers have the benefit of a wider selection of output wavelengths, and can be built to offer less variance in beam parameters such as divergence.

The build is an attractive one, with the pointer chassis being manufactured out of brass, with several components plated in yellow and rose gold. There’s even a sliding window to observe the laser cavity, which glows brightly in operation. [Zenodilodon] goes into great detail during the machining process, showing all the steps required to produce a visually appealing device.

It’s certainly one of the prettiest laser builds we’ve seen, and it’s always nice to see makers exploring different technologies. Similarly to our recently featured 1.4 W laser pointer, it’s largely a packaging operation, but if you’re building your own laser diodes at home – you know where to send ’em. Video after the break.

Continue reading “Building An Optically Pumped Laser Pointer” →

Nerf Mods Via 3D Printing

February 22, 2019 by 2 Comments

Nerf guns are a great way to annoy parents. Simply give them as a gift to any child, and watch precious family heirlooms tumble to the ground as little Holly commando rolls behind the couch to avoid enemy combatants invading the loungeroom. Adults may find them lacking in stopping power and firing rate, but not to worry – there’s plenty to be done about that. [3D Printing Nerd] took a trip to visit the [Out of Darts] workshop, to check out some seriously hardcore blasters.

[Out of Darts] runs as a store that sells all manner of tools and components for hopping up Nerf blasters, but they also sell complete original builds as well. The video showcases all manner of hardware, from powered backpack ammunition hoppers, to drain blaster shotguns and multirocket launchers. The workshop also contains 22 Prusa i3 printers that run 24/7 producing parts, barring breakdowns. Injection moulding, eat your heart out.

Things have come a long way since the old days of swapping in big springs to Hasbro blasters and crossing fingers that nothing breaks. 3D printing allows the home maker to produce just about any part imaginable without requiring advanced machine tools or special skills beyond the use of garden variety CAD software. It’s not the first time we’ve seen 3D printed Nerf blasters, and we’re sure it won’t be the last either. As always, tip ’em if you got ’em. Video after the break.

Continue reading “Nerf Mods Via 3D Printing” →

Supercon: Ruth Grace Wong And Firmware From The Firehose

February 22, 2019 by 13 Comments

Firmware and software are both just code, right? How different could the code that runs Internet-scale distributed web stuff be from the code that runs a tiny microcontroller brain inside a personal hydroponics device? Night and day!

Ruth Grace Wong works in the former world, but moonlights as a manufacturing engineer with some friends. Their product had pre-existing firmware that contained (at least) one bug, and Ruth’s job was to find it. The code in question was written by the Chinese PCB engineer, who knew the electronics intimately but who had no software background, providing Ruth an opportunity to jump head-first into the rawest of raw embedded programming. Spoiler alert: she found the bug and learned a lot about firmware along the way. This talk follows her along the adventure.

“The code is very well documented, in Chinese” but the variable names are insanely non-descriptive. Similarly, while the PCB engineer knows full well what a 24C02 is, if you’re a software geek that might as well be Chinese. As you’d expect, web searches came to the rescue on both fronts.

The bug ended up hiding in a logical flaw in the PWM-setting code inside an interrupt service routine, and it kept the fan from ever coming full on. Once found, it was easily fixed. But getting to the point where you understand the codebase deeply enough to know where to look is four-fifths of the battle. Heck, setting up the toolchain alone can take a day or two.

If you’re a fellow software type, Ruth’s talk (embedded below) will give you a quick glimpse into the outer few layers of the onion that is embedded firmware development, from a familiar viewpoint. Give her quick and value-packed talk a watch! Grizzled hardware veterans will nod along, and maybe even gain a little insight into how our code looks to “them”.

Continue reading “Supercon: Ruth Grace Wong And Firmware From The Firehose” →

Hackaday Podcast 007: Everything Microcontrollers, Deadly Clock Accuracy, CT X-Rays, Mountains Of E-Waste

February 22, 2019 by 5 Comments

Elliot Williams and Mike Szczys look at all that’s happening in hackerdom. This week we dive deep into super-accurate clock chips, SPI and microcontroller trickery, a new (and cheap) part on the microcontroller block, touch-sensitive cloth, and taking a home X-ray to the third dimension. We’re saying our goodbyes to the magnificent A380, looking with skepticism on the V2V tech known as DSRC, and also trying to predict weather with automotive data. And finally, what’s the deal with that growing problem of electronic waste?

Links for all discussed on the show are found below. As always, join in the comments below as we’ll be watching those as we work on next week’s episode!

Take a look at 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 (60 MB or so.)

Where to Follow Hackaday Podcast

Places to follow Hackaday podcasts:

Continue reading “Hackaday Podcast 007: Everything Microcontrollers, Deadly Clock Accuracy, CT X-Rays, Mountains Of E-Waste” →

What Happens When You Cross A Brick With A Pixel?

February 22, 2019 by 19 Comments

There are a great many technologies we use to display information every day. We’re all familiar with plasma displays and LCDs, and then there’s more esoteric hardware like the split flap displays on municipal buses and around train stations.  However, Breakfast have been working on something that turns architectural features into a display at the same time. Enter Brixels.

The name is a portmanteau of brick and pixel, indicating that each individual brick can be independently addressed as a visual element. A Brixel installation consists of a series of columns, stacked with Brixel elements. Each individual brick on the column contains a stepper motor which can set the rotational position of the brick. The outer appearance of the individual bricks is highly customizable, as the motor hardware is integrated into the column itself. A Linux machine is used as a primary controller, which passes commands to each column’s controller over RS485, and the column controllers then pass instructions to each individual Brixel.

The Brixels are capable of continuous 360 degree rotation and also contain LEDs for various illumination based effects. The largest current installation is the Brixel Mirror, standing at 18 feet wide, 6 feet high, and containing 540 individually addressable Brixels. These are built with one half covered in a mirror finish, and combined with a depth-sensing camera for all kinds of fun interactive effects.

Brixels show that architectural features don’t have to be static – they can become kinetic, living things that can be aesthetically beautiful and also useful. Breakfast are known for their installations which use modern electronics to push the limits in their artistic installations. Their work on high-speed flip dot displays is particularly impressive. Video after the break.

[Thanks to Sheldon for the tip!]

Continue reading “What Happens When You Cross A Brick With A Pixel?” →

Drops Of Jupyter Notebooks: How To Keep Notes In The Information Age

February 22, 2019 by 32 Comments

Our digital world is so much more interactive than the paper one it has been replacing. That becomes very obvious in the features of Jupyter Notebooks. The point is to make your data beautiful, organized, interactive, and shareable. And you can do all of this with just a bit of simple coding.

We already leveraged computer power by moving from paper spreadsheets to digital spreadsheets, but they are limited. One thing I’ve seen over and over again — and occasionally been guilty of myself — is spreadsheet abuse. That is, using a spreadsheet program to do something I probably ought to write a program to do. For those times that you want something quick but want something more than a spreadsheet, you should check out Jupyter Notebooks. The system is most commonly associated with Python, but it isn’t Python-specific. There are over 100 languages supported — many community-developed. You can even install a C++ interpreter backend for it. Because of the client/server architecture, it is very simple to share notebooks with other users.

You can — in theory — use Jupyter for anything you could use Python for. In practice, it seems to get a lot of workout with people analyzing large data sets, doing machine learning, and similar tasks.

The Good: Simple, Powerful, Extensible

The idea is simple. Think of a Markdown-enabled web page that can connect to a backend (a kernel, in Jupyter-speak). The backend can run on your machine or remotely and will support some kind of language — often Python. The document has cells that line up vertically (like a single wide spreadsheet column). For example, here’s a simple notebook I created to explain how a bunch of sine waves add up to a square wave:

Continue reading “Drops Of Jupyter Notebooks: How To Keep Notes In The Information Age” →