Author: Jenny List

3536 Articles

A Clock Timebase, No Microcontroller

April 17, 2023 by 20 Comments

Making an electronic clock is pretty easy here in 2023, with a microcontroller capable of delivering as many quartz-disciplined pulses as you’d like available for pennies. But how did engineers generate a timebase back in the old days, and how would you do it today? It’s a question [bicyclesonthemoon] is answering, with a driver for a former railway station clock.

The clock has a mechanism that expects pulses every minute, a +24V pulse on even minutes, and a -24V pulse on odd ones. He received a driver module with it, but for his own reasons wanted a controller without a microcontroller. He also wanted the timebase to be derived from the mains frequency. The result is a delve back into 1970s technology, and the type of project that’s now a pretty rare sight. Using a mixture of 4000 series logic and a few of the ubiquitous 555s [bicyclesonthemoon] recovers 50Hz pulses from the AC, and divides them down to 1 pulse per minute, before splitting into odd and even minutes to drive a pair of relays which in turn drive the clock. We like it, a lot.

Mains-locked clocks are less common than they used to be, but they’re still a thing. Do you still wake up to one?

What Can You Do With Discarded Fish Aggregation Devices

April 13, 2023 by 21 Comments

Often we bring you projects at the end of their trajectory so that you can marvel at a job well done, but sometimes we point you instead to the start of the story. Such is the case with [Brett Smith]’s investigation of discarded fish aggregation buoys, referred to as FADs. These 700-plus dollar devices are deployed in the ocean in the thousands by commercial fishing fleets, and most are not recovered. He’s looking at them from the point of view of re-using their technology in the marine conservation business.

His progress has been documented in a series of short YouTube videos, starting with an introduction that we’ve placed below the break. So far he’s gone on to a complete teardown, and then a detailed look at the PCB. Inside they have a solar charger for a bank of NiCd cells, an echo sounder, a GPS receiver, and an Iridium satellite modem allowing the device to phone home. There’s certainly plenty in there to experiment with, including a few slightly exotic parts, so keep an eye on his channel as we’re sure to see more.

These devices have never made it to Hackaday before, but we have seen an echo sounder on a surfboard.

Continue reading “What Can You Do With Discarded Fish Aggregation Devices” →

Your Fuji Digital Camera Is Hackable

April 8, 2023 by 9 Comments

There was a time when a digital camera was a surprisingly simple affair whose on-board processor didn’t have much in the way of smarts beyond what was needed to grab an image from the sensor and compress it onto some storage. But as they gained more features, over time cameras acquired all the trappings of a fully-fledged computer in their own right, including full-fat operating systems and the accompanying hackability opportunities.

Prominent among camera manufacturers are Fujifilm, whose cameras it turns out have plenty of hacking possibilities. There’s something of a community about them, with all their work appearing in a GitHub repository, and a cracking April Fool in which a Fujifilm camera appears able to be coaxed into running DOOM.

Correction: We’ve since heard from creator [Daniel] who assures us that not only was the DOOM hack very much real, but that he’s released the instructions on how to run the classic shooter on your own Fujfilm X-A2.

Fujifilm cameras past 2017 or so run the ThreadX real-time operating system on a variety of ARM SoCs, with an SQLite data store for camera settings and some custom software controlling the camera hardware. The hackability comes through patching firmware updates, and aside from manipulating the built-in scripting language and accessing the SQLite database, can include code execution.

Don’t have a Fujifilm? They’re not the only hackable camera to be found.

Even Amstrad Spectrums Need Their Bugs Fixing

April 6, 2023 by 2 Comments

The history of the Sinclair ZX Spectrum is one that mirrors the fortunes of the British home computer industry, one of an early 8-bit boom followed by a sharp decline as manufacturers failed to capitalise on the next generation of 16-bit machines. The grey ZX Spectrum on [Keri Szafir]’s bench is one that encapsulates that decline perfectly, being one of the first models produced under the ownership of Amstrad after Sir Clive’s company foundered. Amstrad made many improvements to the Spectrum, but as she demonstrates, there are still some fixes needed.

The machine came her way because of a hum from the tape deck circuitry. The read amplifier was picking up electrical noise, and she fixed it without mods to the circuit but with the simple expedient of powering the analogue circuit from the tape motor switch so it only works when needed.

Beyond that, this machine demonstrates another ’80s innovation, the SCART/Peritel AV connector. These first appeared on early-80s French TV sets, but by the later half of the decade had made it to the UK where Amstrad included support for an adapter cable from the DIN socket on the back of their Spectrum.  Even then they didn’t get it quite right, and she modifies some links on the board to better support it.

Sinclair were famous for on-board bodges, and even in new ownership continued. There’s a reversed transistor and at least one bodged-on component, but of course, it wouldn’t be a Spectrum without bugs, would it!

Continue reading “Even Amstrad Spectrums Need Their Bugs Fixing” →

No Home Cinema Is Complete Without A Motorized Projector

April 5, 2023 by 5 Comments

In the home of the future, everything is automated. Some of us are already there, in dwellings fully tricked-out with IoT and smart home devices. But they don’t somehow look as futuristic as a home in which everything is motorized. We don’t know whether this was the intention, but we certainly get a futuristic vibe from [Sam Baker]’s home cinema projector mount. It’s no mere bracket, instead on command the projector descends from concealment in the ceiling on a custom scissor lift mechanism.

A scissor lift is a simple enough mechanism, but since he was 3D printing one that had to withstand the weight of the projector, it took him a while to get it right. Even the lead screw which drives it is also printed, turned by a stepper motor. As the brains of the unit needn’t be particularly accomplished, an Arduino Nano does the job well enough.

It’s fair to say that his projector isn’t the heaviest of models, but the result glides smoothly down from the ceiling for a perfect home cinema experience. We like it.

Typewriter Mashup Becomes 120-Year-Old Teletype

April 5, 2023 by 13 Comments

Vintage typewriters can be beautiful and elegant devices. But there’s a limit to their value if, as with the 1903 Remington owned by [Daniel Ross], they are fire-damaged and have a seized mechanism. What did he do with what was essentially a piece of scrap metal? Produce an unholy mashup of the vintage machine and a 1988 Sharp daisy wheel typewriter to make a steampunk-style teletype, of course!

Stripping down both machines was evidently no easy task, and the result he’s achieved has the Sharp’s printer mechanism at 90 degrees to its original orientation sitting below the roller in the space once occupied by the Remington’s type bars. We’re sad to see that the keyboard on the older machine appears to be inoperable, but on the other hand each letter does light up as it’s typed.

Meanwhile at the electronics side the components from the Sharp have been transferred to a custom PCB, and the whole can be driven from a 300-baud serial line. As can be seen from the video below the break, the result is an unholy love-child of two typewriters that could scarcely be more different, but somehow it works to make an impressive whole.

If this project looks a little familiar to Hackaday readers, it’s because we’ve mentioned it in passing before. It’s hooked up to his COSMAC Elf retrocomputer, and we saw it in passing a couple of years ago at a much earlier stage of construction before the custom PCB and light-up keyboard.

Continue reading “Typewriter Mashup Becomes 120-Year-Old Teletype” →

A NOR Gate For An ALU?

April 5, 2023 by 18 Comments

If you know anything about he design of a CPU, you’ll probably be able to identify that a critical component of all CPUs is the Arithmetic Logic Unit, or ALU. This is a collection of gates that can do a selection of binary operations, and which depending on the capabilities of the computer, can be a complex component. It’s a surprise then to find that a working CPU can be made with just a single NOR gate — which is what is at the heart of [Dennis Kuschel]’s My4th single board discrete logic computer. It’s the latest in a series of machines from him using the NOR ALU technique, and it replaces hardware complexity with extra software to perform complex operations.

Aside from a refreshingly simple and understandable circuit, it has 32k of RAM and a 32k EPROM, of which about 9k is microcode and the rest program. It’s called My4th because it has a Forth interpreter on board, and it has I2C and digital I/O as well as a serial port for its console.

This will never be a fast computer, but the fact that it computes at all is ts charm. In 2023 there are very few machines about that can be understood in their entirety, so this one is rather special even if it’s not the first 1-bit ALU we’ve seen.

Thanks [Ken Boak] for the tip.