Wristwatch PCB Swaps Must Be In The Air

August 8, 2021 by Mike Szczys 19 Comments

Are we seeing more wristwatch PCB swapping projects because more people are working on them, or because we saw one and they’re on our mind? The world may never know, but when it comes to design constraints, there’s a pretty fun challenge here both in fitting your electronic wizardry inside the confines of an injection molded case, and in the power budget to make your creation run on a sippy straw of battery power.

Just this morning we came across [Joey Castillo’s] sensor-watch project. He chose the Casio F-91W as the donor wristwatch. It’s got that classic Casio look of a segment LCD display capable of displaying hours, minutes, and seconds, as well as day and date. But the added bonus is that we know these have decent water resistance while still providing three buttons for user input. Sure, it’s less buttons than the pink calculator watch we saw [Dave Darko] working on earlier in the week, but which would you trust in the pool?

Replacement PCB sized to use the same battery contact and CR2016 for power [via @josecastillo]

We see that [Joey] also chose to use the ATSAML22 microcontroller and sheds some light on why: it includes a built-in segment LCD controller! If you’re a peripheral geek like us, you can read about the SLCD controller on page 924 of the datasheet (PDF), it’s a whole datasheet onto itself.

The sensor part of the sensor-watch is a flex PCB breakout that allows you to swap in whatever sensor fits your needs. The first to be reflowed at [Joey’s] bench is a BME280 humidity sensor, which is most obviously useful for the included temperature measurements, but maybe it could also alarm at moisture ingress? [Joey] says you can swap in other parts as long as they’re in the QFN or LGA size range. We think an IMU is in order since there’s a lot of fun interaction there like the watch reacting to being positioned in front of your face, or to take tap-based inputs.

We think beginning with a donor watch is brilliant since pulling off a case, especially one that keeps water out, is 97% of the battle. But when your UI is unique to the watch world, sometimes you need to start from scratch like this wooden word clock wristwatch.

A SNES Music Player You Can Control With A Browser

August 8, 2021 by Lewin Day 3 Comments

Listening to chiptunes on an emulator or software-based player is fine, but sometimes you just gotta have that real hardware charm. [Kazhuu] is one such enthusiast who feels this way, and set about building a hardware player for SNES chiptunes that can be controlled from a browser.

The build relies on an Arduino Micro to control the SNES Audio Processing Unit (APU), featuring the Nintendo S-SMP as produced by Sony and designed by Ken Kutaragi. Yes, the father of the PlayStation designed the capable wavetable synthesis chip in the Super Nintendo, and it’s that same hardware that [Kazhuu]’s project interfaces with modern hardware.

With the Arduino’s IO lines hooked up to the APU, song data can be piped out to the Arduino over a serial connection to a PC. This can be handled by a Python script, or more intuitively via a browser-based front-end. This uses WebUSB in order to take input from the browser and then send data out over the USB-serial connection to the Arduino.

It’s a neat demonstration of both working with vintage Nintendo sound hardware and how to code modern browser applications to work with embedded systems. If you’re a SEGA kid, though, you might prefer this build instead. Video after the break.

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Building A Solar Powered Game Boy Pocket

August 8, 2021 by Matthew Carlson 5 Comments

Light has always been a key part of the classic Game Boy experience. Some of us have fond memories of riding along in the back seat of a car at night, pausing and unpausing the game as the street lights overhead briefly give enough light to see the unlit display. The availability of third party IPS displays for these classic handhelds has largely eradicated this problem today, but as you might expect, the increased power requirements of the more modern screen reduces the system’s runtime.

As part of their examination into energy production, the [Houston Museum of Natural Science] set out to see if they could improve things by adding a solar panel to the back of a Game Boy Pocket that had already been modified with an IPS display. The Pocket version of the Game Boy was selected as it has a nice flat back that made it easy to attach a solar panel, and in fact the panel sourced for this mod is so well dimensioned, it almost looks like the device came that way.

In the video below, you can see the modification starts by cutting away a large section of the Game Boy’s rear panel to fit the 1000 mAh LiPo battery. The solar panel is then affixed over the back with super glue. A diode is soldered onto the solar cell, and then wired into a charge controller that came with USB-C input. The placement of the charge controller ended up being trickier than expected, but with a little hot glue, it works just fine. Overall this is a simple mod but a brilliant idea.

This isn’t the first solar-powered handheld game system we’ve seen, but it’s nice to see the idea revisited and expanded on, particularly regarding ergonomics. In addition, we love the incredible detail of narration that’s given as this hack slowly takes shape. Video after the break.

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Giant CNC Machine Measures A Full Cubic Meter

August 8, 2021 by Lewin Day 32 Comments

There are plenty of designs for table-top 3D printers, engravers, and general CNC machines out there. However, if you wanna build big things and build them fast, sometimes you need a machine that can handle bigger jobs. This gigantic 1x1x1 m 5-axis CNC machine from [Brian Brocken] absolutely fits the bill.

The build relies on 3D-printed components and aluminium tubing to make it accessible for anyone to put together. [Brian] notes that 25×25 mm tubing with a 2 mm wall thickness does an okay job, but those aiming to minimize deflection would do well to upgrade to 5 mm thickness instead. Stepper motors are NEMA 23 size, though the Y-axis uses a pair of NEMA 17s. This is necessary to deal with the immense size of the machine. Control is thanks to an Arduino Mega fitted with a RAMPS board, running the Marlin firmware.

The plan is to use the machine to test out a variety of CNC machining techniques. It could make for a great maxi-sized 3D printer, and should be able to handle some basic 5-axis milling of very soft materials like foams. This might seem silly on the face of it, but it can be of great use for mold making tasks.

We’ve seen giant CNC routers built before, too, and they can readily be put to great use. Video after the break.

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The Magnetosphere Has A Ton Of Energy. Can A Guitar Amp Company Tap Into It?

August 7, 2021 by Jenny List 55 Comments

Researching a piece on vacuum tubes, we stumbled on something unexpected from Electro-Harmonix, best known for guitar amplifiers and audio tube manufacture. In a break from their core business, they plan to tap energy from the magnetosphere. This came as something of a surprise to their guitarist customers who were no doubt expecting a fancy new effects pedal, but it seems they’re serious.

The magnetosphere is the region of space surrounding the earth in which the earth’s magnetic field has most influence, and unlike the tidy pattern of magnetic field surrounding a bar magnet that you might have seen with iron filings at school, it’s distorted by the constant buffeting of the solar wind. This means that a significant quantity of potential energy is stored in its compression, and it’s this energy that Electro-Harmonix have their eye on.

Like Fox Mulder: we want to believe. Unfortunately the trouble with such ideas is readily visible with a quick web search; they attract a significant number of what one might charitably call cranks, and there is no shortage of unsubstantiated claims surrounding conspiracy theories, silenced genus inventors, and their mystery devices. Weird and wonderful descriptions and cryptic circuit diagrams abound, so separating the wheat if there is any from the inevitable chaff becomes a challenge. We respect that the Electro-Harmonix team are professional engineers who we hope are unlikely to become caught up in the weirder part of the Internet, but we’ll reserve our judgement until they provide more technical details of what they propose.

Header: NASA, Public domain.

Nintendo Zapper Reborn As Home Automation Remote

August 7, 2021 by Brian McEvoy 3 Comments

Generally, using a gun to turn your lights off is dangerous and expensive, but for the [DuctTape Mechanic], it’s just how he does things. Video also after the break. To be fair, he uses a salvaged Nintendo Zapper, not a firearm, and replaces the guts with an RF transmitter. We are shocked that he chose a radio model instead of infrared seeing as how he is repurposing a light gun, but our scores in Duck Hunt suggest he made the right choice.

The transmitter comes from a keychain remote, so it all fits neatly inside the Zapper chassis. A couple of wires hijack the stock button and run to the stock trigger, so you keep that authentic feel. The receiver side is a bit trickier. When it senses a button press, it sends a pulse, as you would find in a garage door opener, but to keep a lamp on, there needs to be some latching and so there is an Arduino. The microcontroller keeps a tally and operates a 10 amp relay module, so it is mostly acting as the glue between hardware. All of the mains electrical components sit in a blue plastic box with a receptacle on the front.

We don’t see the Zappers used for their intended purposes much anymore because they rely on old technology, but that doesn’t keep people from repurposing the iconic peripheral.

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RAMPS Rebuild Keeps Robox 3D Printer Out Of Junk Bin

August 7, 2021 by Matthew Carlson 11 Comments

A 3D printer is a wonderful invention, but it needs maintenance like every machine that runs for long hours. [Rob Ward] had a well-used Robox 3D printer that was in need of some repairs, but getting the necessary replacement parts shipped to Australia was cost-prohibitive. Rather than see a beloved printer be scrapped as e-waste, he decided to rebuild it using components that he could more easily source. Unfortunately the proprietary software and design of the Robox made this a bit difficult, so it was decided a brain transplant was the best path forward.

Step one was to deduce how the motors worked. A spare RAMPS 1.4 board and Arduino Mega2560 made short work of the limit switches and XYZ motors. This was largely accomplished by splicing into the PCBs themselves. The Bowden filament driver motor had a filament detector and an optical travel sensor that required a bit of extra tuning, but now the challenging task was next: extruding.

With a cheap CR10 hot end from an online auction house, [Rob] began modifying the filament feed to feed in a different direction than the Robox was designed for (the filament comes in at a 90-degree angle on the stock Robox). A fan was needed to cool the filament feed line. Initial results were mixed with lots of blockages and clogs in the filament. A better hot end and a machined aluminum bracket for a smoother path made more reliable prints.

The original bed heater was an excellent heater but it was a 240 VAC heater. Reluctant to having high voltages running through his hacked system, he switched them out for 12 VDC adhesive pads. A MOSFET and MOSFET buffer allowed the bed to reach a temperature workable for PLA. [Rob] upgraded to a GT2560 running Marlin 2.x.x.

With a reliable machine, [Rob] stepped back to admire his work. However, the conversion to the feed being perpendicular to the bed surface had reduced his overall build height. With some modeling in OpenSCAD and some clever use of a standard silicone sock, he had a solution that fed the wire into the back of the hot end, allowing to reclaim some of the build height.

It was a long twelves months of work but the write-up is a joy to read. He’s included STL and SCAD files for the replacement parts on the printer. If you’re interested in seeing more machines rebuilt, why not take a look at this knitting machine gifted with a new brain.