TV Repair By Mail

I don’t think there was ever a correspondence school called the “Close Cover Before Striking School” but since book matches — which used to be a thing when most people smoked — always had that text on them anyway perhaps there should have been. There was a time when electronic magazines, billboards, and even book matches were constantly bombarding us with ads to have a career in electronics. Or computers. Or TV repair. So while we think of distance learning as a new idea, really it is just the evolution of these old correspondence schools which date back quite some time.

How far exactly? Hard to say. There’s evidence of some distance learning going back as far as 1728. In 1837, there was a correspondence course to learn shorthand. By 1858, the University of London started its external program for correspondence work and the University of Chicago had a home study division in 1892.  Radio was an early choice of topic, too. In the United States, the United Wireless Telegraph company started a training school — later the Marconi Institute — in 1909. However, it is doubtful that there was any correspondence training going on there until much later.

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Protect Your Property With This Fire-Breathing Billionaire

Let’s face it: if you can’t trust a fire-breathing billionaire industrialist to protect your stuff, who can you trust? (Video, embedded below.)

This one is straight out of the Really Bad Ideas™ files, and comes to us from [Marc Radinovic]. His story on this one is that he wants to protect the stuff in his new house, and felt that a face-recognition system with a flame thrower would be the best way to address that. And to somehow make it even better, said system would be built into a ridiculous portrait of everyone’s favorite plutocrat. The guts of the system are pretty much what you’d expect — a camera and a Raspberry Pi running OpenCV and a face recognition library, a butane reservoir and a solenoid valve, an arc lighter as an ignition source, and an Arduino and some completely not sketchy at all wiring to control all pieces. And LCD displays for [Elon]’s eyes, of course.

The system is trained to recognize [Marc]’s face and greets him cheerfully when he’s in view. [Non-Marc] people, however, are treated a bit less accommodatingly, up to and including a face-melting fireball. Effigies of other billionaires got the treatment; strangely, [Marc]’s face-recognition algorithm didn’t even recognize another [Mark] as a human face, which when you think about it is pretty darn funny.

So, certainly not a practical security system, and definitely not something you should build, but it’s pretty good fun anyway. It reminds us a bit of the fire-breathing duck we saw years ago.

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Building A Sinclair ZX81 In 2022 With All New Parts

As the supply of genuine retrocomputers dwindles and their prices skyrocket, enthusiasts are turning their eyes in other directions to satisfy their need for 8-bit pixelated goodness. Some take the emulation route, but others demand a solution that’s closer to the original hardware. Following the latter path, [iNimbleSloth] is answering the question as to whether it’s possible to build a Sinclair ZX81 from all-new parts in 2022.

The ZX81 was Sir Clive’s second Z80-based computer, and its low price made it an instant success which paved the way for the legendary ZX Spectrum. From here in 2022 the original Ferranti ULA chip that contained all the logic is unobtainable except by raiding another ’81, so he’s using a design that has the same functionality in 74 series logic. The PCB is the same size as the original, and he’s paired it with a keyboard PCB using tactile switches. The video below the break is the first of what is to be a series, and he will be looking at a readily available 3D printed ZX81 case and the re-manufactured membrane keyboard.

For those of us who first learned to code in its meager 1k of memory the ’81 will always be a special computer. Sure it had many faults, but simply having an affordable real computer at all in 1981 was special. To see one being made from scratch is special then, and it would be nice to think that a few other people might learn how a computer works the Sinclair way.

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A multi-colored chair with a stainless steel frame sits on wooden legs against a grey background.

Recycled Chairs Bring The Subway To Your Living Room

Public transit seats have a rough life. Enduring a number of wear cycles that would make your sofa weep, they take a beating and have to keep looking presentable. When trains and buses are retired, where do the old seats go? A team from the MIT Hobby Shop investigated what was happening to the seats from retiring MBTA Red Line cars and recycled them into stylish chairs.

After some sleuthing and many emails, the MBTA relinquished a number of old subway seats to the team. Since the subway seats didn’t have legs, wood from old church pews was used to create bases. It took one pew end support to create each set of legs, which were cut out on a bandsaw. The old dark stain was sanded off, and the bases were finished with three coats of gel topcoat, letting the natural beauty of the old oak shine through.

We love seeing old things given new life here at Hackaday. If you want to see some more recycled furniture, check out this tire table, this upcycled jeans chair, or these best practices for making box forts.

New Venue Gives Philly Maker Faire A Fresh Start

When we last checked in with the Philadelphia Maker Faire in 2019, one couldn’t help but be impressed with what the organizers had pulled off with just a fraction of the budget and resources it took to put on the defunct World Maker Faire in New York. We came away absolutely certain the event was on the verge of explosive growth, and that next year would be even bigger and better.

But of course, that didn’t happen. The COVID-19 pandemic meant that by the time the 2020 Faire should have kicked off, the logistics of holding a gathering much larger than a family dinner had become a serious hurdle. Philadelphia implemented strict rules on indoor and outdoor events to try and contain the spread of the virus, to the point that even when they were relaxed in 2021, it still didn’t make sense to try and put on a Faire under those conditions.

Thankfully things are largely back to normal-ish now, and as such the Philadelphia Maker Faire had something of a rebirth this year. Organizers decided to move the event to the Independence Seaport Museum, with vendor and exhibitor tables distributed throughout the museum’s three floors. This made the ticket price a great two-for-one value, especially if you had enough time left over to head out to the docks so you could explore the 130-year-old cruiser USS Olympia, and the USS Becuna, one of the last surviving WWII Balao-class submarines.

As you’d expect, the event was packed with fascinating projects and demonstrations, to the point that trying to list them all here would be impossible. But for those who couldn’t make the trip out to see what the 2022 Philadelphia Maker Faire had to offer, let’s take a look at a handful of the standout exhibits.

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An LCD mounted inside a Roland synthesizer

Reverse-Engineering A Display Protocol To Repair A Roland Synthesizer

Repairing electronic devices isn’t as hard as it used to be. Thanks to the internet, it’s easy to find datasheets and application notes for any standard component inside your gadget, and once you’ve found the faulty one, you simply buy a replacement from one of a million web shops — assuming you don’t end up with a fake, of course. When it comes to non-standard components, however, things get more difficult, as [dpeddi] found out when a friend asked him for help in repairing a Roland Juno-G synthesizer with a broken display.

The main issue here was the fact that the display in question was a custom design, with no replacement or documentation available. The only thing [dpeddi] could figure out from the service manual was the basic pinout, which showed a parallel interface with two lines labelled “chip select” — an indication that the display contained two separate controllers. But the exact protocol and data format was not documented, so [dpeddi] brought out his logic analyzer to try and decode the signals generated by the synthesizer.

After a bit of trial and error, he was able to figure out the protocol: it looked like the display contained two KS0713-type LCD controllers, each controlling one half of the screen. Finding a compatible replacement was still proving difficult, so [dpeddi] decided instead to decode the original signals using a microcontroller and show the picture on a modern LCD driven by SPI. After some intial experiments with an ESP32, it turned out that the task of reading two reasonably fast parallel buses and driving an even faster serial one was a bit too much for the ESP, so [dpeddi] upgraded to a Raspberry Pi Pico. This worked a treat, and thanks to a 3D-printed mounting bracket, the new display also fit snugly inside the Roland’s case.

The Pico’s code is available on [dpeddi]’s GitHub page, so if you’ve also got a dodgy display in your Juno-G you can simply download it and use it to plug in a brand-new display. However, the method of reverse-engineering an existing display protocol and translating it to that of a new one is pretty universal and should come in handy when working with any type of electronic device: say, a vintage calculator or multimeter, or even another synthesizer.

An acrylic map of the state of Lagos. Each region is lit a different color by LEDs shining on the acrylic panels. The colors coorespond to the air quality index key which is lit in cooresponding colors to the value.

Hackaday Prize 2022: This Interactive Air Quality Map Makes The Invisible Visible

Air quality can have a big impact on your health, but it isn’t always something you can see. [Ahmed Oyenuga] wanted to make air quality something more tangible and developed an Interactive Air Quality Map.

Using addressable LEDs and acrylic panels, [Oyenuga]’s map lights up different regions of his state (Lagos) with colors that correspond to qualitative values of the air quality readings. The color key on the edge of the map becomes a readout when you touch a specific region of the map.

Most of the map’s functionality is handled by an Arduino WiFi 1010, but the capacitive touch is running on a custom board [Oyenuga] designed with an ATSAMD21J17. [Oyenuga] is getting air quality data via a DesignSpark Environmental Sensor Development Kit (ESDK) and then uses reverse geocoding to take the GPS data and turn it into a location the map will understand.

If you’re interested in different options for monitoring air quality that could feed into a map like this, why don’t you check out this LoRa Air Quality Monitor or even a Mobile Air Quality Monitor.

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