Old Phone, New Remote Switch

With mobile phones now ubiquitous for the masses in much of the world for over two decades, something a lot of readers will be familiar with is a drawer full of their past devices. Alongside the older smartphone you’ll have a couple of feature phones, and probably at the bottom a Nokia candybar or a Motorola flip phone. There have been various attempts over the years to make use of the computing power the more recent ones contain through using their smartphone operating systems, but the older devices remain relatively useless.

[Vishwasnavada] has a neat plan though, using an ancient phone as a remote trigger device, by interfacing it with an Arduino. There are many ways this could be achieved depending on the model of the phone in question, but one thing common to nearly all devices is a vibration motor. Removing the motor and taking its power line to a GPIO allows the Arduino to sense when the phone is ringing. The idea then is that a call can be placed to the phone which is not picked up, but because it triggers the vibration motor it can be used to make the microcontroller do something remotely. A hack with limited capabilities then, but one that is cheap and simple, uses a recycled device, and should work almost anywhere populated on the planet given the global reach of 2G networks.

This isn’t the first respin of a classic Nokia we’ve brought you, they will also talk data.

Hacking A Very Special 486

It’s fair to say that Moore’s Law is not delivering on its promise of advancing semiconductor capabilities as fast as it used to, as the limits of current fabrication techniques are being met. Where this is being written for example there are two laptops, one from the last year and one that is 11 years old, and while the new one is undeniably faster it has not overtaken the other by as much as a ten year gap between 1990s machines would have revealed.

So with older laptops being still so relatively quick, what possible attraction could there be for working on a machine from the 1990s, when the Moore’s Law curve was steeper? It’s something [Jim W] is doing, with his HP Internet Advisor (J2522B), and when you see the machine in question perhaps you’ll understand why. The J2522B is a laptop, but it’s no ordinary ’90s road warrior’s status symbol. This 486-powered beast is a piece of test equipment, specifically one for examining Ethernet ports, thus it’s built like a tank and is mains powered only. It boasts a 486DX4, 16 MB of memory, a then-colossal 1.3 GB hard drive, and an ISA Fast Ethernet card. Oh, and WIndows 95, which with a couple of decades’ hindsight seems an amusing choice to power a piece of security test equipment.  Impressive specs for the day, but the $20,000 price tag would still have been steep compared to a comparable laptop.

[Jim]’s machine is destined for classic gaming, though with only the little HP pop-out mouse you saw on their Omnibook range at the time, he needed a PS/2 port. Some chipset hunting found that, but at the cost of accidentally frying a MOSFET when a screen connector was incorrectly re-inserted. We’re then treated to a guide to substituting older MOSFETs with modern parts, useful in itself, but followed by a marvelous piece of bodge work as an SOIC-8 part is placed on a DPAK footprint.

This is an interesting series of posts, partly from a retro angle as they deal with an interesting machine, but also from a hacking angle as he’s getting closer to the vintage PC hardware than most of us to. Keep an eye on it, there is sure to be more in the pipeline.

Build A Boat With Your Buddies

It’s probably a dream common to many groups of friends among the Hackaday readership: go away together to a sunny island some time in the summer, take a load of beer and maybe a BBQ, and build something. Some of us get close to it at hacker camps such as Toorcamp or EMF, but few do it as well as [KristianKalm] and his friends. Their time on an island resulted in a boat, and what a boat it is!

To be fair, this is not a craft you’d sail the high seas in, its unique hull design rendered in single-skin plywood might have some stability issues and probably would have difficulty maintaining structural integrity in a high sea. But it’s perfect for their summer time backwater, with its electric outboard, steering wheel, and seat from a Russian saloon car.

The plans are fairly simple, cut from two sheets of ply it has an angular pointed front, sloping sides, and a fairly narrow bottom. Our experience with river boats would have led to a wider flat-bottomed hull, but this one looks stable enough for their purposes. Everything is held together with PVA glue and extra pieces of wood over the joints, something that amazingly keeps the water at bay. It is fairly obviously a rather basic and ever some might say rather ugly boat, but we’d guess there are few readers who wouldn’t want to give it a spin as part of a summer holiday.

If this has caught your fancy, don’t panic, the Northern Hemisphere still has some summer left, and all you need to do is find a plastic barrel!

Thanks [Keith Olson] for the tip!

The C.H.I.P Returns, Maybe

Remember the C.H.I.P? The little ARM-based and Linux-capable single board computer that was launched in 2015 at what was then a seemingly impossibly cheap price of $9, then took ages to arrive before fading away and the company behind it going under? Like a zombie, it has returned from the dead!

So, should we be reaching for the staples of zombie movies, and breaking out the long-playing records? Or should we be cautiously welcoming it back into the fold, a prodigal son to the wider family of boards? Before continuing, it’s best to take a closer look.

The C.H.I.P that has returned is a C.H.I.P Pro, the slightly more powerful upgraded model, and it has done so because unlike its sibling it was released under an open-source licence. Therefore this is a clone of the original, and it comes from an outfit called Source Parts, who have put their board up for sale via Amazon, but with what looks suspiciously like a photo of an original Next Thing Co board. We can’t raise Source Parts’ website as this is being written so we can’t tell you much about its originator and whether this is likely to be a reliable supplier that can provide continuity, so maybe we’d suggest a little caution until more information has emerged. We’re sure that community members will share their experiences.

It’s encouraging to see the C.H.I.P Pro return, but on balance we’d say that its price is not the most attractive given that the same money can buy you powerful boards that come with much better support. The SBC market has moved on since the original was a thing, and to make a splash this one will have to have some special sauce that we’re just not seeing. If they cloned the Pocket C.H.I.P all-in-one computer with keyboard and display, now that would catch our attention!

It all seemed so rosy for the C.H.I.P at launch, but even then its competitors doubted the $9 BoM, and boards such as the Raspberry Pi Zero took its market. The end came in March this year, but perhaps there might be more life in it yet.

Thanks [SlowBro] for the tip.

How Low Can You Go? Tiny Current Generator

Current limited power supplies are a ubiquitous feature of the bench, and have no doubt helped prevent many calamities and much magic smoke being released from pieces of electronics. But for all their usefulness they are a crude tool that has a current resolution in the range of amps rather than single digit milliamps or microamps.

To address this issue, [Yann Guidon] has produced a precision current source, a device designed to reliably inject tiny currents. And in a refreshing twist, it has an extremely simple circuit in the form of a couple of PNP transistors. It has a range from 20 mA to 5 µA which is set and fine-tuned by a pair of pots, and it has a front-panel ammeter hacked from a surplus pocket multimeter, allowing the current to be monitored. Being powered by its own internal battery (and a separate battery for the ammeter) it is not tied to the same ground as the circuit into which its current is being fed.

[Yann] is a prolific builder whose work has featured here more than once. Take a look at his rubidium reference and his discrete component clocks, for example, and his portable LED flash.

Bomb Hoist Teardown Shows Cold-War-Era Big Iron

Buying surplus equipment lends a frisson of excitement as you eagerly await the package or crate containing your purchase. Did you buy a hidden treasure, or has some shyster succeeded in unloading a pile of garbage onto you, their mark? [Professor Churls] shelled out $49.99 for a military surplus bomb hoist which definitely falls into the former category. His teardown reveals it to be a beautifully over-engineered piece of Cold-War-era American hardware.

As the package with its extremely heavy contents is first inspected, he reminds us just what a bomb hoist does, it is clipped to an aircraft by ground crew and serves as a small but extremely powerful crane to lift up to a 6000-pound piece of ordnance onto the wing pylon of an aircraft. This particular example dates from the 1960s, and features a 28-volt DC motor coupled to a bulky gearbox assembly on a swivel mount for attachment.

His teardown is extremely detailed, but such is the engineering and complexity of the device you’ll want to read every part of it. The motor is a fairly traditional separately-excited brushed DC design such as you’d expect from that era, but with unusual features such as brushes on pivots rather than a slide. The multiple sets of gears are packed in aged and phenolic-smelling grease, and have unusual features such as stub-form teeth for high torque at low durations. There is even an entirely separate gear train for the hex drive provided so that crews could keep the bombers rolling even when the power was out.

He leaves us with the tantalising information that there is a project awaiting this device, but doesn’t tell us what that might be. We hope we’ll get to see it, whatever it is. Meanwhile it’s great to see that this kind of item can still be found from military surplus suppliers, where this is being written they have degenerated into little more than stockists of camouflage-printed camping gear. Our colleague [Brandon Dunson] lamented in 2015 on the slow decline of the electronic surplus business in his location.

Review: SMD Tweezer Meter Or Tweezer Probes For Your Multimeter?

It’s remarkable how tiny electronics have become. Heaven knows what an old-timer whose experience started with tubes must think, to go from solder tags to SMD in a lifetime is some journey. Even  the generation that started with discrete transistors has lived through an incredible shift. But it’s true, SMD components are tiny, and that presents a challenge aside from the one you’ll face when soldering them. Identifying and measuring the value of a chip component too small to have any writing upon it becomes almost impossible with a pair of standard test probes.

Happily the test equipment manufacturers have risen to the challenge, and produced all sorts of meters designed for SMD work that have a pair of tweezers instead of test prods. When I was looking for one I did my usual thing when it comes to Hackaday reviews. I looked at the budget end of the market, and bought an inexpensive Chinese model for about £16($21). And since I was browsing tweezers I couldn’t resist adding another purchase to my order. I found a pair of tweezer test probes for my multimeter which cost me just over a pound ($1.30) and would provide a useful comparison. For working with SMD components in situ, do you even need the special meter?

Continue reading “Review: SMD Tweezer Meter Or Tweezer Probes For Your Multimeter?”