Author: Jenny List

3279 Articles

Dillo Turns 25, And Releases A New Version

January 19, 2025 by 13 Comments

The chances are overwhelming, that you are reading this article on a web browser powered by some form of the Blink or WebKit browser engines as used by Google, Apple, and many open source projects, or perhaps the Gecko engine as used by Firefox. At the top end of the web browser world there are now depressingly few maintained browser engines — we think to the detriment of web standards evolution.

Moving away from the big players though, there are several small browser projects which eschew bells and whistles for speed and compactness, and we’re pleased to see that one of the perennial players has released a new version as it passes its quarter century.

Dillo describes itself as ” a fast and small graphical web browser”, and it provides a basic window on the web with a tiny download and the ability to run on very low-end hardware. Without JavaScript and other luxuries it sometimes doesn’t render a site as you’d see it in Chrome or Firefox, but we’re guessing many users would relish some escape from the web’s cycle-sucking garbage. The new version 3.2.0 brings bug fixes, as well as math formula rendering, and navigation improvements.

The special thing about Dillo is that this is a project which came back from the dead. We reported last year how a developer resurrected it after a previous release back in 2015, and it seems that for now at least it has a healthy future. So put it on your retro PC, your original Raspberry Pi, or your Atari if you have one, and try it on your modern desktop if you need reminding just how fast web browsing can be.

This isn’t the only interesting browser project on the block, we’re also keeping an eye on Ladybird, which is aiming for those big players rather than simplicity like Dillo.

Thanks [Feinfinger] for the tip.

A PDA From An ESP32

January 18, 2025 by 17 Comments

The ESP32 series of microcontrollers have been with us for quite a few years now and appeared in both Tensilica and RISC-V variants, both of which deliver an inexpensive and powerful device. It’s thus shown up in quite a few handheld computers, whether they be conference badges or standalone devices, and this is definitely a field in which these chips have more to give. We’re pleased then to see this e-ink PDA from [ashtf8], which we think raises the bar on this type of device.

At its heart is an ESP32-S3, on the back side of a QWERTY keyboard PCB, and for a display it has an e-ink screen. To get over the annoying e-ink refresh when typing text it uses a hybrid of e-ink and OLED, with a small OLED holding the current line which can be periodically sent to the e-ink. Perhaps the nicest thing about the hardware though is the clear resin printed clamshell case, and a hand-cast silicone membrane for the keyboard. That has always been a part considered difficult to produce, and here he is making one from scratch. Take a look at the video below the break.

Software-wise it has a range of apps with more promised, but even as it stands it looks useful enough to work with. If that’s not enough, then perhaps an ESP32 operating system would help.

Continue reading “A PDA From An ESP32” →

No Crystal Earpiece? No Problem!

January 17, 2025 by 11 Comments

A staple of starting off in electronics ion years past was the crystal set radio, an extremely simple AM radio receiver with little more than a tuned circuit and a point contact diode as its components. Point contact diodes have become difficult to find but can be replaced with a cats whisker type detector, but what about listening to the resulting audio? These circuits require a very high impedance headphone, which was often supplied by a piezoelectric crystal earpiece. [Tsbrownie] takes a moment to build a replacement for this increasingly hard to find part.

It shouldn’t have come as a surprise, but we were still slightly taken aback to discover that inside these earpieces lies the ubiquitous piezoelectric buzzer element. Thus given a 3D-printed shell to replace the one on the original, it’s a relatively simple task to twist up a set of wires and solder them on. The result is given a test, and found to perform just as well as the real thing, in fact a little louder.

In one sense this is such a simple job, but in another it opens up something non-obvious for anyone who needs a high impedance earpiece. The days of the crystal radios and rudimentary transistor hearing aids these parts were once the main target for may both have passed, but just in case there’s any need for one elsewhere, now we can fill it. Take a look at the video, below the break.

Fancy trying a crystal radio? We’ve got you covered.

Continue reading “No Crystal Earpiece? No Problem!” →

Piezo Buzzer Makes A Drum

January 15, 2025 by 6 Comments

The humble piezo disc buzzer is much more than something that makes tinny beeps in retro electronic equipment, it can also be used as a sensor. Tapping a piezo buzzer gives an interesting waveform, with a voltage spike followed by an envelope, and then a negative rebound voltage. It’s something [Igor Brichkov] is using, to make a simple but effective electronic drum.

First of all, the output of the buzzer must be tamed, which he does by giving it a little impedance to dissipate any voltage spikes. There follows some simple signal conditioning with passive components, to arrive at an envelope for the final drum sound. How to turn a voltage into a sound? Using a voltage controlled amplifier working on a noise source. The result is recognizably the drum sound, entirely in electronics.

In a world of digital music it’s easy to forget the simpler end of sound synthesis, using circuits rather than software. If you hanker for the Good Old Days, we have an entire series on logic noise, doing the job with 4000 series CMOS logic.

Continue reading “Piezo Buzzer Makes A Drum” →

A Direct Conversion Receiver Anyone Can Build

January 15, 2025 by 28 Comments

A couple of years ago one of the Hackaday Prize finalists was a project to take highschoolers through building a direct conversion radio receiver for the 40 metre amateur band. It was originated by the SolderSmoke podcast, and we’re pleased to see that they’ve recently put up an overview video taking the viewer through the whole project in detail.

It’s a modular design, with all the constituent building blocks broken out into separate boards on which the circuitry is built Manhattan style. Direct conversion receivers are pretty simple, so that leaves us with only four modules for oscillator, bandpass filter, mixer, and audio amplifier. We particularly like that it’s permeability tuned using a brass screw and an inductor, to make up for the once-ubiquitous variable capacitors now being largely a thing of the past.

A point that resonated was that most radio amateurs never make something like this. Arguments can be made about off-the-shelf rigs and chequebook amateurs, but we’d like to suggest that everyone can benefit from a feel for analogue circuitry even if they rarely have a need for a little receiver like this one. We like this radio, and we hope you will too after seeing the video below the break.

Need reminding? See the Hackaday.io project page, and the Hackaday Prize finalists from that year.

Continue reading “A Direct Conversion Receiver Anyone Can Build” →

It’s A Doughnut, In Hardware

January 14, 2025 by 8 Comments

Making a physical doughnut is easy enough, given a good dough recipe and a nice hot deep fat fryer. But have you ever considered making a one in physical electronic hardware, on an ASIC? [A1k0n] has, at least in terms of making a virtual doughnut. It’s a hardware implementation of a ray tracer which renders a rotating doughnut to a VGA screen, and it comes courtesy of around 7000 logic cells on the latest iteration of Tiny Tapeout.

We will not pretend to be mathematical or ray tracing experts here at Hackaday so we won’t presume to explain in detail the circuitry, suffice to say that the clever hack here lies in a method using only shift and add operations rather than the complex trigonometry we might expect. It uses a slightly esoteric VGA mode to work with the device clock, so while CRT monitors have no problems it can have artifacts on an LCD. The full explanation goes into great detail, for the math heads among you.

We’ve reported on quite a few Tiny Tapeout projects over the years, as the many-ASICs-on-a-chip extends its capabilities.

It’s A Bench, But It’s Not Benchy

January 12, 2025 by 27 Comments

Whatever the nuances are surrounding the reported taking down of remixes derived from the famous Benchy 3D printer stress test, it was inevitable that in its aftermath there would be competing stress tests appear under more permissive licensing. And so it has come to pass, in the form of [Depep1]’s Boaty, a model that’s not a boat, but a bench. Sadly this is being written away from a 3D printer so we can’t try it, but we can immediately see that its low bed contact area from having spindly legs would be a significant test for many printers’ bed adhesion, and it has overhangs and bridges aplenty.

It’s always interesting to see new takes on a printer stress test, after all we can all use something to check the health of our machines. But the Benchy saga isn’t something we think should drive you away from the little boat we know and love, as it remains an open-source model as it always has been. We don’t know the exact reasons why the derivatives were removed, but we understand from Internet scuttlebut that the waters may be a little more cloudy than at first supposed. If there’s any moral at all to the story, it lies in reading and understanding open source licences, rather than just assuming they all allow us to do anything we want.

Meanwhile it’s likely this model will be joined by others, and we welcome that. After all, innovation should be part of what open source does.

Missed the Benchy takedown story? Catch up here.

Thanks [Jeremy G] for the tip.