Vacuum Exposure Unit Gives Better PCB Etching Results

PCB etching seems to be a subject that sharply divides our community into those who are experts in it and etch themselves every PCB they use, and those who have significant quantities of ferric chloride stained clothing in their past and for whom the advent of cheap commercial PCB manufacture and CNC milled PCB prototyping have been the best thing since sliced bread.

Your likely success when etching your own boards is most dependent on the quality of your preparation and your equipment. If you began your PCB career with etch-resist transfers and a permanent marker with a Tupperware tub of etchant, then later progressed to laser toner or photographic masking and a bubble etcher, you’ll understand this.

[Jana Marie Hemsing] has drawn our attention to this very nicely built PCB etching suite (Translation, German original) at the Warpzone hackerspace (Translation, German original) in Münster, Germany. The foil pattern is printed on transparency and exposed to UV light over a photoresist coated board with a vacuum pump arrangement to ensure as good a contact as possible to the board for the sharpest result. They have two exposers, one for single sided and the other for double-sided boards, both are very well-built from what looks like plywood.

The attention to detail continues with a home-made magnetic stirrer and heated bubble etching tank Their etchant of choice is sodium persulphate, so there are none of those brown ferric chloride stains.

PCB etching is nothing new, indeed we have covered the subject extensively over the years. But we think you’ll agree, if you’re going to etch your own PCBs you should have as good a set-up as you can, and Warpzone’s PCB suite is rather well put together. Those of us in spaces with lesser facilities should be getting ideas from it.

Hackaday Prize Entry: AutoFan Saves Tired Drivers With Face Recognition

Long distance driving can be tedious at times. The glare of the sun and the greenhouse effect of all your car’s windows make it hot and dry. You turn on the fan, or air conditioning if you have it, and that brings relief. Soon enough you’ve got another problem, the cold dry air is uncomfortable on your eyes. Eventually as you become more tired, you find yourself needing the air on your face more and more as you stay alert. You thus spend most of the journey fiddling with your vents or adjusting the climate controls. Wouldn’t it be great if the car could do all that for you?

AutoFan is a project from [hanno] that aims to automate this process intelligently. It has a fan with steerable louvres, driven by a Raspberry Pi 2 with attached webcam. The Pi computes the position of the driver’s face, and ensures the air from the fan is directed to one side of it. If it sees the driver’s blink rate increasing it directs the air to their face, having detected that they are becoming tired.

The build logs go into detail on the mathematics of calculating servo angles and correcting for camera lens distortion in OpenCV. They also discuss the Python code used to take advantage of the multicore architecture, and to control the servos. The prototype fan housing can be seen in the video below the break, complete with an unimpressed-looking cat. For those of you interested in the code, he has made it available in a GitHub repository.

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Retrotechtacular: Railroads In The Jet Age

The front of the Soviet jet train on a monument in Tver, Russia. By Eskimozzz [PD], via Wikimedia Commons.
The front of the Soviet jet train on a monument in Tver, Russia. By Eskimozzz [PD], via Wikimedia Commons.
It started with one of those odd links that pop up from time to time on Hacker News: “The strange and now sadly abandoned Soviet Jet Train from the 1970s“. Pictures of a dilapidated railcar with a pair of jet engines in nacelles above its cab, forlorn in a rusty siding in the Russian winter. Reading a little further on the subject revealed a forgotten facet of the rivalry between Russians and Americans at the height of the Cold War, and became an engrossing trawl through Wikipedia entries, rail enthusiast websites, and YouTube videos.

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RC Car Piloting With The Blast Shield Down

Many of us have had a radio controlled car at some time in our youth, though it’s probable that none all of us entirely mastered it. There are memories of spectacular crashes, and if we were really unlucky, further boosts to Mr. Tamiya’s bank balance as fresh parts had to be fitted.

[Paul Yan] was watching his young son with a radio controlled toy, and was struck by how the two-joystick control layout is not necessarily as intuitive as it could be. By contrast when faced with a console game with first-person view and a steering wheel the boy had no problem dropping straight into play. This observation led him to investigate bringing a console steering wheel to an RC car, and the result is a rather impressive FPV immersive driving experience.

Paul's FPV car, explained.
Paul’s FPV car, explained.

His build took a PS2 steering wheel peripheral with pedals and mated it to an Arduino Uno via a PS2 shield. The Uno talks to a Nordic NRF24L01 RF module, which communicates with another NRF24L01 on the car. This in turn talks to a car-mounted Arduino Micro, which controls the car servos and speed controller.

FPV video is provided by a miniature camera and transmitter from the world of multirotor flying which is mounted on the car and transmits its pictures over 5GHz to a set of monitor goggles. Sadly he does not appear to have posted any of the software involved, though we doubt there is anything too challenging should you wish to try it for yourselves.

The video below shows the car in action, complete with an over-enthusiastic acceleration and crash from his young son. He tells us it’s a similar experience to playing a racing kart game in the real world, and having seen the video we wish we could have a go.

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Hackaday Prize Entry: Neopixel Pocket Watch

A timepiece is rather a rite of passage in the world of hardware hacking, and we never cease to be enthralled by the creativity of our community in coming up with new ones.

Today’s example comes from [Joshua Snyder], who has made a pocket watch. Not just any pocket watch, he’s taken the shell of a clockwork watch and inserted a ring of Neopixels, which he drives  from an ESP8266 module. Power comes from a small LiPo battery, and he’s cleverly engineered a small push-button switch so that it can be actuated by the knob from the original watch. Different colour LEDs traverse the ring to simulate the hands of a traditional timepiece, and the whole nestles behind the perforated cover of the watch shell for something of a steampunk feel.

He admits the battery life is not very good at the moment, probably because for now the WiFi is always enabled so he can reach its web interface for debugging. Sadly he appears to have not yet posted the software, but he does tell us it uses NTP to update its time, and that it supports over-the-air updating for new versions. He suggests a future version might dispense with the ESP and use an ATtiny or similar with a real-time clock giving better battery life.

We’ve covered a lot of LED timepieces over the years, including quite a few watches. Only a small selection are this PIC LED ring in a pocket watch case, another LED ring this time powered by an ATMega645, and this very stylish OLED wristwatch.

The Surprising Story Of The First Microprocessors

If you maintain an interest in vintage computers, you may well know something of the early history of the microprocessor, how Intel’s 4-bit 4004, intended for a desktop calculator, was the first to be developed, and the follow-up 8008 was the first 8-bit device. We tend to like simple stories when it comes to history, and inventions like this are always conveniently packaged for posterity as one-off events.

In fact the story of the development of the first microprocessors is a much more convoluted one than it might appear, with several different companies concurrently at the forefront of developments. A fascinating recent IEEE Spectrum piece from [Ken Shirriff] investigates this period in microprocessor design, and presents the surprising conclusion that Texas Instruments may deserve the crown of having created the first 8-bit device, dislodging the 8008 from its pedestal. Continue reading “The Surprising Story Of The First Microprocessors”

Review: The National Museum Of Computing

Here’s a question for you all: how will you know when you are no longer young? When you fall out of love with contemporary popular music perhaps, or start to find the idea of a cruise holiday attractive? The surefire sign for many people is having to ask a teenager how a piece of technology works — this is probably not that applicable to most Hackaday readers.

How about when you’re shocked to encounter a significant part of your youth in a museum? These are supposed to be places of The Olden Days, full of rustic agricultural tools or Neolithic pottery, yet here you are in front of your teenage years presented for all to see. You have two choices: you can surrender to the inevitable and henceforth only wear beige clothing, take up golf or maybe book that old person’s cruise holiday, or you can dive in misty-eyed and reacquaint yourself with everything in front of you.

The above is probably an experience many regulars of these pages would share on a visit to Britain’s National Museum Of Computing in a corner of the famous Bletchley Park site, home of Britain’s wartime codebreaking efforts. They describe what they do on their web site as follows:

We conserve, restore, reconstruct, and give hands-on access to historic computers and related artefacts – with a particular focus on those which were the result of pioneering British ingenuity.

For the visitor this means that their galleries contain a huge array of computing and associated equipment, many of which are presented as working exhibits without too much of the dumbing-down that pervades so many other museums, and that the staff are extremely knowledgable about them.

The museum is housed in one of the groups of wartime codebreakers’ huts, laid out roughly in the shape of a capital H with the top of one vertical lopped off. If you are a connoisseur of British wartime sites you’ll recognise these buildings, they were built to a fairly standard design all over the country. Internally this means that the galleries are structured around the long corridors that are a staple of that era, giving in particular the earlier exhibits a feel of their time.

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