Author: Jenny List

3362 Articles

Every 3D Printable Film Camera, In One Place

April 1, 2026 by 4 Comments

For those of us who hack old cameras, the 3D printer has undoubtedly been a boon. High precision, or at least consistent precision, lightproof enclosures can be easily made and reproduced for others. As a result there are quite a few printable cameras out there, and we’ve featured our share here. We didn’t realize just how many there are without the work of [Sebastian] though, as he’s gathered together every one he can find in a glorious catalog of homemade photographic construction.

As a snapshot of the world of home made cameras it’s refreshing to see such a wide range of designs. There are pinholes aplenty as well as cameras using lenses from scavanged point and shoots through 35mm SLR, medium format, and even one using a Micro Four Thirds compact digital camera lens. For film there’s 35mm and 120 as well as large format, but we’re pleased to see a few instant cameras in there. Some of the models in the list are paid-for designs but most of them are free, so you probably won’t need any encouragement to make yourself a camera!

Unless we missed something, we didn’t see any movie cameras in the list. With 35mm and 16mm models to be found, we hope some of them make it.

Mercury Audio Cables, So Nobody Else Has To Do It

April 1, 2026 by 64 Comments

We’ve seen our fair share of audiophile tomfoolery here at Hackaday, and we’ve even poked fun at a few of them over the years. Perhaps one of the most outrageously over the top that we’ve so far seen comes from [Pierogi Engineering] who, we’ll grant you not in a spirit of audiophile expectation, has made a set of speaker interconnects using liquid mercury.

In terms of construction they’re transparent tubes filled with mercury and capped off with 4 mm plugs as you might expect. We hear them compared with copper cables and from where we’re sitting we can’t tell any difference, but as we’ve said in the past, the only metrics that matter in this field come from an audio analyzer.

But that’s not what we take away from the video below the break. Being honest for a minute, there was a discussion among Hackaday editors as to whether or not we should feature this story. He’s handling significant quantities of mercury, and it’s probably not over reacting to express concerns about his procedures. We wouldn’t handle mercury like that, and we’d suggest that unless you want to turn your home into a Superfund site, you shouldn’t either. But now someone has, so at least there’s no need for anyone else to answer the question as to whether mercury makes a good interconnect.

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A Novel 555 Circuit In 2026

April 1, 2026 by 22 Comments

The humble NE555 has been around for over five decades now, and while during that time we’ve seen a succession of better and faster versions of the original, the circuits which surround it are pretty well known. There can’t be anything new in the world of 555s, can there? [Stephen Woodward] claims he’s made a novel 555 circuit, with his 1 MHz linear voltage to frequency converter. Since he’s been in love with the 555 since 1974, we’re inclined to trust him on this part.

It’s visibly the 555 astable oscillator we’re all familiar with, given the addition of a current source in place of the normal charging resistor. This makes for a much more linear sawtooth waveform, but it still doesn’t fix the linearity of the voltage to frequency curve. The novel bit comes in adding an extra resistor between the threshold and discharge pins, with a value calculated for a time constant with the capacitor to match the 555’s own switching delay. This provides the necessary compensation, and gives the circuit its linearity.

This is so brilliantly simple that it’s almost a shock that it’s new, but it’s also a great example of the old-school electronic engineer’s art. We can’t think of an immediate need for a 555 voltage to frequency converter on the Hackaday bench at the moment, but you can bet we’ll come back to this one if we do.

We had someone pushing a newer 555 variant to its limit, when we ran our component abuse challenge.

An Oscilloscope The Way They Used To Be

March 31, 2026 by 7 Comments

It’s likely that Hackaday has a readership with the highest percentage of oscilloscope ownership among any in the world, and we’re guessing that most of you who fit in that bracket have a modern digital instrument on your bench. It’s a computer with a very fancy analogue front end, and the traces are displayed in software. Before those were a thing though, a ‘scope was an all-analogue affair, with a vacuum-tube CRT showing the waveform in real time. [Joshua Coleman] has made one of these CRT ‘scopes from scratch, and we rather like it.

Using a vintage two inch round tube, it includes all the relevant power supplies and input amplifiers for the deflection plates. It doesn’t include the triggers and timebase circuitry you’d expect from a desktop instrument though, so unless you add a sawtooth on its X input it’s only good for some Lissajous figures. But that’s not the point of a project like this one, because it’s likely even the cheapest of modern ‘scopes way exceeds any capabilities it would have even if it were fully formed. It’s a talking point and an attractive demonstration of a bit of early-20th-century physics, which probably many of us would appreciate if it were ours.

A video of the device is below the break, meanwhile we’ve taken a look in the past at the prehistory of the oscilloscope.

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The Most Intricate Of Freeform Digital Clocks

March 25, 2026 by 11 Comments

Digital clock projects have been with us since the 1970s, when affordable LEDs and integrated circuits became available. In 2026 most of them use a microcontroller, but for the AliExpress fans there’s one that goes straight back to the ’70s with a pile of logic chips. You can make it on the supplied PCBs, but that wasn’t for [ALTco]. Instead, he made the circuit in free form, using six metres of brass wire.

The construction is anchored together by a set of busbars that carry sockets for a set of seven-segment and driver modules. The circuit is typical for the day, with a crystal oscillator and divider chain feeding the counters for the displays. There are a few clever tricks that older engineers might recognize in order to reduce the chip count. In this case that’s negated by an extra set of circuitry allowing the time to be set from a rotary encoder.

We’re impressed by the intricacy of the device, made bit by bit without a plan, it as some wires what thread their way between others. It’s a truly beautiful piece, and it reminds us of our circuit sculpture contest back in 2020.

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The 3DFX Voodoo Lives Again In An FPGA

March 22, 2026 by 36 Comments

The 3DFX Voodoo was not the first dedicated 3D graphics chipset by any means, but it became the favourite for gamers among the early mass-market GPUs. It would be found on a 3D-processing-only PCI card that sat on the feature connector of your SVGA card. The Voodoo took any game that supported its Glide API into the world of (for the time) smooth and beautiful 3D. They’re worth a bit now, but if you don’t fancy forking out for mid-’90s silicon in 2026, there’s another option. [Francisco Ayala Le Brun] has implemented the 3DFX Voodoo 1 in SpinalHDL for FPGAs.

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ESP32: When Is A P4 A P4, But Not The P4 You Thought It Was

March 21, 2026 by 28 Comments

We’re used to electronic parts of the same type staying predictably the same, sometimes over many years. An early Z80 from the mid 1970s can be exchanged with one from the end of production a few years ago, for example. This week, we’ve had DMs from several readers who’ve found that this is not always the case, and the culprit is surprising. Espressif has released a new revision of their P4 application processor, and though it’s ostensibly the same, there are a couple of changes that have been catching people out.

The changes lie in both hardware and software, in that there’s a pin that’s changed from NC to a power rail, a few extra passives are needed, and firmware must be compiled separately for either revision. The problem is that they are being sold as the same device and appear in some places under the same SKU! This is leading to uncertainty as to which P4 revision is in stock at wholesalers. We’ve been told about boards designed for the old revision being assembled with the new one, a situation difficult to rework your way out of. Designers are also left uncertain as to which firmware build is needed for boards assembled in remote factories.

The ESP32-P4 is an impressive part for its price, and we’re sure that we’ll be seeing plenty of projects using this new revision over the coming years. We’re surprised that it doesn’t have a different enough part number and that the wholesalers have seemingly been caught napping by the change. We’re told that some of the well-known Chinese assembly houses are now carrying the two chips as separate SKUs, but that’s scant consolation for a designer with a pile of boards carrying the wrong part. If you’re working with the P4, watch out, make sure your board is designed for the latest revision, and ask your supplier to check which chips you’ll get.

If the P4 is new to you, we’ve already seen a few projects using it.