The PT2399 Delay/Echo Chip Data Sheet You Never Had

If you are fortunate enough to have had the opportunity to play with an analogue-reel-to-reel tape recorder in a well-equipped studio, you probably looped the tape around to create an echo, or a delay in the audio. It was a desirable effect to have, but not a practical one for a guitar pedal or similar portable accessory. Silicon alternatives for creating delays have been in production since the 1960s, first the so-called bucket brigade delay lines that used a switched chain of on-chip capacitors, and more recently all-digital chips that process the delay by storing samples in RAM. One of the more popular of those is the Princeton Technology PT2399, but it comes with something of a snag for the experimenter in the form of a sparse data sheet. Thankfully the folks at [Electrosmash] have come to the rescue on that front with a thorough technical examination of the chip that should fill in any gaps in the official documentation.

After a brief examination of the range of chips of which the 2399 is a part, they dive right into the chip’s internals by rearranging the internal circuit diagram from the data sheet to the point at which it makes more sense. At which point the difference between the chip’s delay and echo functions becomes obvious, through the inclusion of a feedback path.

We then are taken through the pins, examining what lies behind the power supply and analog inputs and outputs. We are somewhere between a data sheet and an app note here, as some of this is information rarely present even in really good data sheets. Finally, we are taken through the chip’s performance, with real-world distortion and noise measurements. Armed with this page, the would-be PT2399 designer really can say they know what they are working with.

Surprisingly few PT2399s have appeared on these pages, however one did pop up in the Synthbike.

An Optical Mouse Sensor For Robotic Vision

Readers with long memories will remember the days when mice and other similar pointing devices relied upon a hard rubber ball in contact with your desk or other surface, that transmitted any motion to a pair of toothed-wheel rotation sensors. Since the later half of the 1990s though, your rodent has been ever significantly more likely to rely upon an optical sensor taking the form of a small CCD camera connected to motion sensing electronics. These cameras are intriguing components with applications outside pointing devices, as is shown by [FoxIS] who has used one for robot vision.

The robot in question is a skid-steer 4-wheeled toy, to which he has added an ADNS3080 mouse sensor fitted with a lens, an H-bridge motor driver board, and a Wemos D1 Mini single board computer. The D1 serves a web page showing both the image from the ADNS3080 and an interface that allows the robot to be directed over a network connection. A pair of LiPo batteries complete the picture, with voltage monitoring via one of the Wemos analogue pins.

The ADNS3080 is an interesting component and we’d love see more of it. This laser distance sensor or perhaps this car movement tracker should give you some more info. We’ve heard rumors of them being useful for drones. Anyone?

Retrotechtacular: Constructing A Car Engine

Oxford is a city world-famous for its university, and is a must-see stop on the itinerary of many a tourist to the United Kingdom. It features mediaeval architecture, unspoilt meadows, two idylic rivers, and a car plant. That’s the part the guide books don’t tell you, if you drive a BMW Mini there is every chance that it was built in a shiny new factory on the outskirts of the historic tourist destination.

A 1930s Morris Ten Series II. Humber79 [CC BY-SA 3.0].
A 1930s Morris Ten Series II. Humber79 [CC BY-SA 3.0].
The origins of the Mini factory lie over the road on a site that now houses a science park but was once the location of the Morris Motors plant, at one time Britain’s largest carmaker. In the 1930s they featured in a British Pathé documentary film which we’ve placed below the break, part of a series on industry in which the production of an internal combustion engine was examined in great detail. The music and narration is charmingly of its time, but the film itself is not only a fascinating look inside a factory of over eight decades ago, but also an insight into engine manufacture that remains relevant today even if the engine itself bears little resemblance to the lump in your motor today.

Morris produced a range of run-of-the-mill saloon cars in this period, and their typical power unit was one of the four-cylinder engines from the film. It’s a sidevalve design with a three-bearing crank, and it lacks innovations such as bore liners. The metallurgy and lubrication in these engines was not to the same standard as an engine of today, so a prewar Morris owner would not have expected to see the same longevity you’d expect from your daily.

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A Pick-And-Place That Is A Work Of Art

It’s a Holy Grail among hackerspaces, the possession of a pick-and-place machine. These robotic helpers for placing surface-mount components on PCBs are something of a gateway to electronic production, but they can carry a fearsome cost. Happily for the cash-strapped would-be electronic manufacturer, it is possible to build a pick-and-place for yourself. [Mcuoneclipse] has demonstrated this with a rather impressive build that works with the freely available OpenPnP software.

Superficially it shares much with what you might expect from a small CNC mill, in that it has a frame made from extruded aluminium that carries rails that trace an X and a Y axis supporting a tool head. But instead of a blade it has a box made from laser-cut ply that contains a camera and a vacuum pick-up tool that can collect a component from the tapes and deposit it in the correct point on the board. At the machine’s heart is a Smoothieboard, and the work is done by an assortment of solenoid valves and actuators. A huge amount of attention to detail has been paid to this build, with a holder for all the interchangeable nozzles for different component sizes, laser-cut mountings for all the motorised components, and automatic feeders for the SMD tapes all being carefully designed and built. Several iterations of the design are presented, in particular around the head itself which has passed through more than one form to remove as much vibration as possible. But don’t take it from us, have a look at the video we’ve pasted in below the break.

This isn’t the first pick-and-place machine we’ve brought you here at Hackaday. If you already have a 3D printer, would you consider this upgrade?

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The Electric Vehicles Of EMF Camp: A Sinclair C5, (Almost) As It Should Have Been

Most Hackaday readers will have heard of [Clive Sinclair], the British inventor and serial entrepreneur whose name appeared on some of the most fondly-recalled 8-bit home computers. If you aren’t either a Sinclair enthusiast or a Brit of a Certain Age though, you may not also be aware that he dabbled for a while in the world of electric vehicles. In early 1985 he launched the C5, a sleek three-wheeler designed to take advantage of new laws governing electrically assisted bicycles.

The C5 was a commercial failure because it placed the rider in a vulnerable position almost at road level, but in the decades since its launch it has become something of a cult item. [Rob] fell for the C5 when he had a ride in one belonging to a friend, and decided he had to have one of his own. The story of his upgrading it and the mishaps that befell it along the way are the subject of his most recent blog post, and it’s not a tale that’s over by any means.

The C5 was flawed not only in its riding position, the trademark Sinclair economy in manufacture manifested itself in a minimalist motor drive to one rear wheel only, and a front wheel braking system that saw bicycle calipers unleashed on a plastic wheel rim. The latter was sorted with an upgrade to a disc brake, but the former required a bit more work. A first-generation motor and gearbox had an unusual plywood housing, and the C5 even made it peripherally into our review of EMF Camp 2016, but it didn’t quite have the power to start the machine without pedaling. Something with more grunt was called for, and it came in the form of a better gearbox which once fitted allowed the machine to power its way to the Tindie Cambridge meetup back in April. Your scribe had a ride, but all was not well. After a hard manual pedal back across Cambridge to the Makespace it was revealed that the much-vaunted Lotus chassis had lived up to the Sinclair reputation for under-engineering, and bent. Repairs are under way for the upcoming EMF Camp 2018, where we hope we’ll even see it entering the Hacky Racers competition.

The BBC Computer Literacy Project From The 1980s Is Yours To Browse

In the early 1980s there was growing public awareness that the microcomputer revolution would have a significant effect on everybody’s lives, and there was a brief period in which anything remotely connected with a computer attracted an air of glamour and sophistication. Broadcasters wanted to get in on the act, and produced glowing documentaries on the new technology, enthusiastically crystal-ball-gazing as they did so.

In the UK, the public service BBC broadcaster produced a brace of series’ over the decade probing all corners of the subject as part of the same Computer Literacy Project that gave us Acorn’s BBC Micro, and we are lucky enough that they’ve put them all online so that we can watch them (again, in some cases, if a Hackaday scribe can get away with revealing her age).

You can see famous shows such as the moment when the presenters experienced a live on-air hack while demonstrating an early online service, but most of it is a fascinating contemporary look at the computers we now enthuse over as retro devices. Will the MSX sweep all before it, for example? (It didn’t).

They seem very dated now with their 8-bit micros (if not just for the word “micro”), synth music, and cheesy graphics. But what does come across is the air of optimism, this was the future, and it was packaged not as a threat, but as a good place to be. Take a look, but make sure you have plenty of time. You may spend a while in front of the screen.

We’ve mentioned int he past another spin-off from the Computer Literacy Project, the Domesday Project.

Thanks [Darren Grant] for the tip.

 

A Sneak Peek At The TS100 Soldering Iron’s Younger Sibling

Many readers will be familiar with the TS100 soldering iron, a lightweight and powerful tool with an integrated temperature controller in its handle based upon an STM32 microcontroller. As an iron it’s a joy to use, it has hackable code, and it has become a firm favourite within our community. There have been rumours of a TS100 stablemate for some time now, with the model number being touted as a TS200 and with it being said to be USB-C powered. But beyond those tidbits, until now there has been not a lot to go on.

So [Marco Reps]’ video that we’ve placed below the break is a particularly interesting one, featuring as it does a prototype of the iron in question. It’s called the TS80 but there is evidence on its PCB that it has held the TS200 moniker in the past, it’s USB-C powered, and it features a new integrated heating element and bit with a Weller-style 3.5mm jack connector.

He runs it through a battery of tests and finds it to perform very well indeed, sometimes better than the TS100 despite his not having a USB-C power source capable of supplying the same voltage that his TS100 gets through its DC jack. To be clear, the TS100 is still a very good iron indeed, this one is simply a little bit better. Inside a sturdier metal barrel is a PCB with the STM32 on board as well as an OLED display that looks a little smaller than the one on the TS100. The shorter element receives praise, while the TS100 is hardly a long iron it is always good to get as close to the action as possible.

There is a concern over the lack of a DC jack and its reliance on USB-C, though he points out that with the appropriate cables and increasing USB-C adoption this should not remain a problem for long. We’d be interested to ensure that it can be powered through the USB-C socket from a simple DC power source such as a battery though, as that flexibility is such a bonus with the TS100.

So then, the TS80 is coming, but the TS100 is still a very good iron indeed so there’s no need to throw yours away any time soon. It’s an iron we look forward to seeing when it arrives though, and no doubt we’ll give you our verdict.

You can see our TS100 review if that takes your fancy, and while you’re at it take a look at one of the community’s most awesome TS100 hacks. [Marco] muses on how long it’ll be before someone has their TS80 playing audio through that 3.5mm jack.

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