Author: Jenny List

3292 Articles

An Even Smaller World’s Smallest LED Blinky

April 11, 2019 by 14 Comments

Everything can be done with a 555. It’s a universal law, as all readers know. And a flashing light, you might think, will have been done before many times. But nobody has ever created a 555 flashing light as small as thie one created by [TWires], who has taken a TI LMC555 chip-scale packaged 555 and dead-bugged a working flasher on its surface using 01005 discrete components. There is a video showing it in operation that we’ve placed below the break, and it’s tiny. We probably all consider ourselves to be quite good at soldering, but this piece of work is in another class entirely.

The project was inspired by [Mike Harrison]’s previous holder of the smallest blinky prize, which used a PIC microcontroller atop a tiny surface mount supercapacitor. It uses the same capacitor for power, but we’d say it’s taken the blinky to new levels of tininess. Does this mean a new arms race is upon us in the world of tiny blinkies? We hope so, and though it’s difficult to imagine they can get much smaller we can’t wait to see what people come up with. If there’s one thing about our community it’s that saying something can’t be done is unwise: one of you will find a way if it is at all possible. Even Microchip’s MIC1555 might be a bit big though, so something inventive is called for.

For a fascinating run-down of the state of the 555 art, read this article from our own [Ted Yapo].

Continue reading “An Even Smaller World’s Smallest LED Blinky” →

Blacksmithing For The Uninitiated: Let’s Talk About Anvils

April 10, 2019 by 29 Comments

When you grow up with something as the constant backdrop to your life, it’s easy to forget as an adult that not everyone else shares your instinctive knowledge of the subject. My dad is a blacksmith, he’s now retired, but as I was growing up his very active forge was in a workshop next to our house. This is the second part of a series based upon that experience, exploring blacksmithing for people who have maybe always fancied a go at the anvil but have little idea where to start.

The Most Obvious Blacksmithing Tool: The Anvil

Having considered the hearth in our previous outing, it’s time to turn our attention to what is the signature piece of blacksmithing equipment: the anvil. This has the function of providing a high-mass hardened working surface against which metal can be forged, and it has a distinctive shape with various parts for particular metalworking tasks. There are many minor and major variations of anvil design depending upon where in the world your anvil hails from, but since my experience comes from the English counties, the anvil I will be describing is the pattern you’ll find in the British Isles.

Continue reading “Blacksmithing For The Uninitiated: Let’s Talk About Anvils” →

Restoring An HP LCZ Meter From The 1980s

April 7, 2019 by 11 Comments

We are fantastically lucky not only in the parts that are easily available to us at reasonable cost, but also for the affordable test equipment that we can have on our benches. It was not always this way though, and [NFM] treats us to an extensive teardown and upgrade of a piece of test equipment from the days when a hacker’s bench would have been well-appointed with just a multimeter and a 10MHz ‘scope.

The Hewlett Packard 4276A LCZ meter is, or perhaps was, the king of component testers. A 19″ rack unit that would comfortably fill a shelf, it has a host of functions and a brace of red LED displays. This particular meter had clearly seen better days, and required a look inside just to clean up connectors and replace aged batteries.

In the case is a backplane board with a series of edge connectors for a PSU, CPU, and analogue boards. Aged capacitors and those batteries were replaced, and those edge connectors cleaned up again. The CPU board appears to have a Z80 at its heart, and we’re sure we spotted a 1987 date code. There are plenty of nice high-quality touches, such as the individual 7-segment digits being socketed.

An after-market option for this equipment included a DC offset board, and incredibly HP publish its full schematic and a picture of its PCB in their manual. It was thus a simple process and quick PCB ordering to knock up a modern replica, with just a few component substitutions and single resistors replacing an HP specific encapsulated resistor pack.

As a treat we get a ringside seat for the set-up and alignment of the machine. The DC offset board gives the wrong voltage, which he traces to a voltage reference with a different tolerance to the original HP part. [NFM] makes some adjustments to resistor values, and is able to pull the voltage to the correct value. Finally we see the instrument put through its paces, and along the way have a demonstration of how capacitance of a ceramic capacitor can vary with voltage close to its working voltage. Even if you never have the need for an LCZ meter or never see an HP 4276A, this should be worth a watch. And if you now have an urge to find a bench full of similar treasures, take a look at our guide to old test equipment.

Continue reading “Restoring An HP LCZ Meter From The 1980s” →

A Vintage Sony Portable TV, Brought Up To Date

April 6, 2019 by 5 Comments

In the time before smartphones for on-the-go visual entertainment, there were portable TVs. You might think of a portable TV as a luggable device, but the really cool ones were pocket-sized. Perhaps if you are familiar with pocket TVs you’ll be thinking of a Citizen or a Casio with a matchbox-sized LCD, but before those devices reached the market there was an earlier generation that featured tiny CRTs. These were simply the coolest electronics that an ’80s kid could lust after, and [Nick Reynolds] is lucky enough to have one. It’s a Sony Watchman from some time in the first half of that decade, and because it’s useless in the age of digital broadcasts he’s upgraded it by installing a Raspberry Pi in its case.

The unlikely inspiration for the project came from the 1970s British sci-fi TV series Space 1999, in which portable CRT-based communicators were a prop. They were typical of the sci-fi vision of the future in shows of the period, one that got so much right but didn’t quite see the smartphone coming.

The Watchman features Sony’s angled CRT, and fitting a Pi Zero W into the limited space behind it called for some careful insulation of its parts with Kapton tape. He’s even included a Pi camera module with a contorted run of flexible cable, placing it beneath the screen where a tuning indicator once sat. He has no sound as yet, but is able to demonstrate a working videophone using Ekiga as a client. He has a few more Watchmen, and has plans for a suite of retro videophones, and a Pi 3 based model.

Surprisingly this isn’t the only Sony Watchman that’s had this kind of treatment, previously we’ve brought you one that hosted a Pong game.

Cambridge Mini Uncon: Robots, Light Boxes, PCB Watches, And Retro Computers

April 5, 2019 by 9 Comments

At Hackaday, we are nothing without our community. We meet up at conferences, shows, and camps, but one of our favourite way to congregate is with the Unconference format. It’s an event where you can stand up and give an eight-minute talk about what is important to you, and what you are working on.

Thank you to the Cambridge Makespace for hosting our most recent a Mini Unconference. Let’s take a look at the excellent talks and demos that highlighted the day!

Continue reading “Cambridge Mini Uncon: Robots, Light Boxes, PCB Watches, And Retro Computers” →

In Praise Of The App Note

April 2, 2019 by 36 Comments

When I am at a loss for an explanation in the world of electronics, I reach for my well-thumbed Horowitz & Hill. When H&H fails me which is not that often, the chances are I’ll find myself looking in an application note from a semiconductor company who is in cut-throat competition with its rivals in a bid for my attention. These companies have an extensive sales and marketing effort, part of which comes in the dissemination of knowledge.

Razor blades may be sold to young men with images of jet fighters and a subtle suggestion that a clean-shaven guy gets his girl, but semiconductor brands are sold by piquing the engineer’s interest with information. To that end, companies become publishing houses in praise of their products. They produce not only data sheets that deal with individual device, but app notes documents which cover a wider topic and tell the story of why this manufacturer’s parts are naturally the best in the world.

These app notes frequently make for fascinating reading, and if you haven’t found them yet you should head for the documentation sections of semiconductor biz websites and seek some of them out.

Continue reading “In Praise Of The App Note” →

Let A Dinosaur Show You The Future

April 1, 2019 by No comments

Our lives in the 21st century are in part governed by a series of systems which we rarely encounter directly but which can have a great impact upon our lives. The oil futures market, for example, for which [Igor Nikolic] has created a real-time visualisation in the form of a clock in which the “hand” is a plastic dinosaur (As ever, XKCD reminds us that oil contains homeopathic quantities of real dinosaur, but it makes a good talking point).

The clock is part of a series continuing from his previous grid balance lamp project which monitored supply and demand in the electricity grid, and takes a feed of oil futures pricing to an MQTT server which is then picked up by an ESP8266 in the clock. The dinosaur hand is attached to a stepper motor, the position of which is set according to the market movements. There are also three LEDs whose colours change according to price. The whole is mounted on a plaque made from the top of an oil drum, and placed for effect over a map of the Port of Rotterdam, one of Europe’s busiest trading hubs.

Monitoring of these invisible socio-technical systems is a fascinating subject, and in the past we have brought you news of the very real impact they can have on entire continents when international politics intrude.