Author: Jenny List

3286 Articles

Using Your Phone As A Microscope On The Electronics Workbench

February 5, 2021 by 28 Comments

One aspect of working for Hackaday comes in our regular need to take good quality photographs for publication. I have a semi-decent camera that turns my inept pointing and shooting into passably good images, but sometimes the easiest and quickest way to capture something is to pull out my mobile phone.

It’s a risky step because phone camera modules and lenses are tiny compared to their higher quality cousins, and sometimes the picture that looks good on the phone screen can look awful in a web browser. You quickly learn never to zoom on a mobile phone camera because it’s inevitably a digital zoom that simply delivers grainy interpolated pictures.

That’s not to say that the zoom can’t be useful. Recently I had some unexpected inspiration when using a smartphone camera as a magnifier to read the writing on a chip. I don’t need an archival copy of the image… I just needed a quick magnifying tool. Have I been carrying a capable magnifier for soldering in my pocket or handbag for years without realising it? I decided to give it a try and it worked okay with a few caveats. While I have seen optics turn these cameras into pretty good microscopes, my setup added nothing more than a phone tripod, and will get you by in a pinch.

Continue reading “Using Your Phone As A Microscope On The Electronics Workbench” →

A Four-Year-Old Event Badge Makes An Environmental Sensor

February 4, 2021 by 2 Comments

By now we’re all used to the requirements imposed by the pandemic, of social distancing and wearing masks indoors. But as [polyfloyd] and the rest of the board at Bitlair hackerspace in Amersfoort in the Netherlands were concerned, there are still risk factors to consider when inside a building.  Without fresh air the concentration of virus-bearing droplets can increase, and the best way they could think of to monitor this was to install a set of CO2 sensors. To run them they didn’t need to buy any new hardware, instead they turned to a set of event badges, from 2017s SHA hacker camp.

This badge sported an ESP32 module with an e-ink screen, and of most interest for this project it still has a supported software platform and comes with a handy expansion connector on the rear. The commonly-available MH-Z19 infra-red CO2 sensor and BME280 humidity sensor fit on a PCB that follows the shape of the badge with a protrusion at the top on which they appear as an integrated unit. Processing those readings is a MicroPython badge app that issues warnings via MQTT and plots a CO2 graph on the screen. Everything is available, both the hardware in a GitHub repository and the software as a badge.team app.

We applaud anyone who makes use of an event badge for a project, and especially so for using one years after the event. The SHA badge and its descendants are uniquely suited to this through their well-supported platform, so if you have one in a drawer we’d urge you to pull it out and give it a try.

A USB-PD Laptop Conversion In Extreme Detail.

February 3, 2021 by 31 Comments

With USB-PD slowly making wall wart power supplies obsolete and becoming the do-it-all standard for DC power, it’s a popular conversion to slap an off-the-shelf USB-PD module in place of the barrel jack in a laptop. Not when it comes to [jakobnator] though, who fitted his Dell with an upgrade lovingly and expertly crafted for both electrical and mechanical perfection.

The video that you can find below the break is a long and detailed one, but in that detail lies touches that set the conversion apart from the norm. We’re treated to a full-run-down of USB-PD module design and chip programming, and then the mechanics of the 1-wire chip through which the Dell ties itself in with only Dell power supplies. Programming this chip in particular is something of a challenge.

It’s the mechanical design that sets this one apart. He started with an odd-shaped space that had contained the barrel jack socket and a ferrite choke, and designed a PCB to fit it exactly. 3D-printing a model to check for fit is attention to detail at the stratospheric level. The result is a fit that looks almost as though it was part of the original manufacture, and which should keep the laptop useful for years to come.

This may be the most elegant USB-C laptop conversion we’ve seen, but it’s not the only one.

Continue reading “A USB-PD Laptop Conversion In Extreme Detail.” →

All The Best Computers From Cambridge Boot To Basic

February 1, 2021 by 77 Comments

The Raspberry Pi is a fine machine that appears in many a retrocomputing project, but its custom Linux distribution lacks one thing. It boots into a GNU/Linux shell or a fully-featured desktop GUI rather than as proper computers should, to a BASIC interpreter. This vexed [Alan Pope], who yearned for his early days of ROM BASIC, so he set out to create a Raspberry Pi 400 that delivers the user straight to BASIC. What follows goes well beyond the Pi, as he takes something of a “State of the BASIC” look at the various available interpreters for the simple-to-code language. Almost every major flavour you could imagine has an interpreter, but as is a appropriate for a computer from Cambridge running an ARM processor, he opts for one that delivers BBC BASIC.

It would certainly be possible to write a bare-metal image that took the user straight to a native ARM BASIC interpreter, but instead he opts for the safer route of running the interpreter on top of a minimalist Linux image. Here he takes the unexpected step of using an Ubuntu distribution rather than Raspberry Pi OS, this is done through familiarity with its quirks. Eventually he settled upon a BBC BASIC interpreter that allowed him to do all the graphical tricks via the SDL library without a hint of X or a compositor, meaning that at last he had a Pi that boots to BASIC. Assuming that it’s an interpreter rather than an emulator it should be significantly faster than the original, but he doesn’t share that information with us.

This isn’t the first boot-to-BASIC machine we’ve shown you.

Header image:  A real BBC Micro BASIC prompt. Thanks [Claire Osborne] for the picture.

13,000 Regular Expressions Make An Editor’s Life Easier

February 1, 2021 by 41 Comments

Being an editor is a job that seems deceptively easy until you are hauled over the coals for letting a textual howler go to print (or website). Most publications have style guides to ensure that their individual voice is preserved, but even the most eagle-eyed will sometimes slip up in their application. At the Guardian newspaper in the UK they have been struggling with this against an ever-evolving style guide that must adapt to fast-moving world events, to the extent that they had a set of regular expressions to deal with commonly-occurring problems. A lot of regular expressions, in fact around 13,000 of them.

Clearly some form of management was required, and  a team of developers set about taming this monster. The result is Typerighter, their server-side document-checker, which can be found in a GitHub repository. Surprisingly for rule management they started with a Google Sheet, a choice which proved unexpectedly robust when working with such a long list even though they later replaced it. The back end doing the job of text matching was written in Scala, and for the front end a plugin was created for their Prosemirror text editor.

For a publication of course this is extremely interesting, but where’s the interest for hackers? The answer lies in any text-processing engine that uses a lot of regular expressions; those of you who have dabbled in this space will know how unwieldy this work can become. Any user of computational linguistic techniques in the pursuit of language processing could probably find much of interest here.

If you’re a bit hazy on regular expressions, how about the episode on them from our long-running Linux-fu series?

This Hot Air Gun Is Either A Work Of Genius Or Lethal, We Can’t Decide

January 31, 2021 by 31 Comments

One of the essentials on the bench is some form of hot air gun. Whether it’s a precision tool intended for reworking PCBs or the broad-stroke item used for paint stripping, we’ve all got one somewhere. The paint-stripping variety are pretty cheap, but not as cheap as [Porcas Pregos e Parafusos]’s home made hot air gun. This slightly hair-raising device is made from a variety of junk parts and delivers hot air, though we suspect the possibility for burning the operator remains high.

At its heart is one of those mains powered water boiler elements designed to be lowered into a cup or similar, and since such devices would burn out if not cooled in some way, there is a fan from a microwave oven passing air over it. The whole thing sits inside an aluminium cone cut from a circular cake tin, and is held together on a wooden chassis to which the handle and power switch from a defunct electric drill provide the operator with something to hold on to.

As you can see from the video below the break it makes for an effective hot air gun, but one that we’re guessing you’d soon learn to avoid touching on the metal cone. Still, as a community we’re used to this with our soldering irons, as the RevSpace T-shirt puts it: “If it smells like chicken, you’re holding it wrong“.

Strangely, this isn’t the first DIY heat gun we’ve seen.

Continue reading “This Hot Air Gun Is Either A Work Of Genius Or Lethal, We Can’t Decide” →

A Heat Reclaimer For Your Woodstove; The One Thing It’s Not Is Cool

January 30, 2021 by 27 Comments

It’s the middle of winter for those of us who live in the Northern Hemisphere, which naturally turns minds towards heating, or sometimes the lack of it. It’s particularly difficult for those who rely on a wood stove to escape the feeling that perhaps most of that hard-won heat may be whistling up the chimney rather than keeping them warm. It’s a problem [Lou] has addressed with his DIY chimney heat reclaimer.

As can be seen from the video below the break, his stove appears to be in a workshop, and has a long single-wall metal stove pipe. Over the outside of this he’s placed a pair of T pieces joined by a longer length of pipe all of a larger bore, and a mains-powered fan forces air through this air jacket. The result is a continuous flow of hot air that he claims delivers a 45% heat reclamation. We’re curious though whether the reduction in flue temperature might cause extra tar condensation and thus the build-up of flammable material further up the chimney. The stove itself is a double barrel affair with access for smoking, and the video describing it is worth a look in itself.

Whatever the stove, be sure to ensure a constant supply of fuel!

Continue reading “A Heat Reclaimer For Your Woodstove; The One Thing It’s Not Is Cool” →