Turning Fruits Into Ethylene And Ethane Refrigerant

One of the best parts about DIY chemistry and physics projects is that you get to decide how early in the supply chain you want to begin, such as with [Hyperspace Pirate]’s adventures in ethanol production from sugar fermentation. Although you can certainly just buy packs of sugar and yeast from the store and pretend that this will be helpful once the world embraces its Mad Max era, you may as well start with the stuff that actually grows on trees, like fruit.

While you could use the ethanol produced this way as ethanol fuel in combustion engines and the like, you can also turn the ethanol into ethylene and ethane. That way you can fill up your refrigerator, freezer, and air conditioner to keep your perishable foods and yourself fresh as the outside world descends into highly questionable fashion choices.

Even outside such a scenario it makes sense to generate your own ethane and ethylene, due to how much these refrigerants cost. Once you have the ethanol, some aluminium oxide catalyst at 350°C is enough to produce ethylene and water. Producing ethane is admittedly a bit more involved, requiring acetobacter bacteria to produce acetic acid, along with baking soda, a platinum anode and a few more odds and ends.

Producing butene and even longer chains from ethylene is also possible as a next step, but this gets even hairier than producing ethane from ethanol, so we’re likely to see this in a future update after all the low-hanging fruit has been harvested.

Continue reading “Turning Fruits Into Ethylene And Ethane Refrigerant”

A KVM Without The V (Or The M)

Many of us will be used to the idea of a KVM, a device that pipes keyboard, video, and mouse over the network from a remote machine to your own. But many remote machines don’t run a GUI, so there’s not always the need for a full video experience. Enter [morpheuslord] with the PicoTTY. It’s somewhere between an old-fashioned serial terminal and a KVM.

The system has two components, a Pi Pico which plugs in to the USB port of each client machine and connects to the network with a WIZnet W5100S Ethernet Hat, and a Pi Zero 2 W which forms the hub. The Pico acts as both a keyboard and a serial terminal, and streams both to the user via a web interface on the Zero.

We can see the use of a machine like this, but we have a few questions. Why for instance is the keyboard needed, given that the serial terminal could provide input in itself. But however it works we can see it might have a use in cases where a terminal can’t be accessed over the network directly, and we especially like it that a single USB peripheral does the job that a conventional KVM would use a bunch of cables for.

If it’s a more conventional KVM you seek, they can now be done using a microcontroller.

Architectural LED Install Shows How To Do It With Style

Anyone can string up some LED string lights in a space with mixed results. However, if you want to create a lighting environment that’s classy and stylish, it takes a little more finesse. [ipad.bendavid] has a great example of this, with a rather tidy architectural LED installation.

The final look is quite clean and evenly lit, without requiring the use of any diffuser material.

The electronic side of things is relatively straightforward. There’s an ESP32 running the show, commanding the colors for 928 individually-addressable WS2812 RGB LEDs. It uses the WebSocket API for real time control, integrates with Home Assistant, and even offers audio reactive lighting modes with the aid of an INMP441 I2S audio input module. A hefty 5 V, 60 A power supply ensures the LEDs are never short of juice. There was also careful attention paid to power distribution to avoid any dim spots or other issues.

Where it gets really cool, though, is the attention paid to the construction of the installation. The LED strips are installed in concentric square frames, which block light in specific areas to create a nice square pattern, with the LEDs facing the wall they’re installed on rather than projecting out to the viewer. This hides the strips themselves and eliminated the need for diffusers which can be a pain to get right.

Overall, the build is a pleasing one that plays with light and darkness and looks rather stylish in a way so many LED installs don’t. If you’re cooking up your own neat glowable projects, you know we’d love to see them on the tipsline.

The Seven Sensors And Breakout Boards To Avoid In A Product

We’ve all seen these sensors and modules kicking around, as part of beginner kits, strapped into prototypes and potentially even in products deployed in the field. Yet as [John Teel] rightfully points out in a recent video, most of these have no business ever being used in a real product, and might not even be suitable for prototyping.

First up is a combination of the related DHT11 and DHT22 temperature-humidity sensors. As common as these are, they’re also pretty sketchy with their proprietary one-wire protocol and at most questionable accuracy, worsened by not having a good supply chain. The replacements are plentiful: the SHT40 and SHT41, the Bosch Sensortec BME280 or BMP180, as well as TI’s HDC3020. These get you standard I2C communication and a supply chain plus a datasheet you can trust.

Second is the HC-SR04 ultrasonic distance sensor. Although fine for prototyping, it’s a 5 V module, lacks temperature compensation and other features that’d be needed outside a temperature-controlled room. Here ST’s VL53 Time-of-Flight sensors are a good alternative, containing a range of sensors of which we covered the fancier VL53L5CX previously for 3D scanning a room. Of course, you can also use reflective IR as a good cheap alternative.

Third is the HC-SR501 passive infrared (PIR) motion module. This one is also fine for PIR and motion sensing prototyping, but is too inconsistent and power-hungry for production. Instead you can get much better and much smaller PIR modules, like the Panasonic EKMC and EKMB, or the ST STHS34 IR motion and presence sensor.

Continue reading “The Seven Sensors And Breakout Boards To Avoid In A Product”

UV Printer? 3D Printer? HeyGears Says “Why Not Both”?

There’s a new contender in the prosumer UV printer world up on Kickstarter, the HeyGears G1. This one’s particularly interesting as they’re explicitly marketing it as being able to produce full-color 3D prints along with the “print-on-anything” functionality we’ve come to expect from a UV flatbed printer.

You get two choices of bed, with the larger being 420 mm x 320 mm x 130 mm. Hardly the largest build volume we’ve seen around here. You can fill that with up to 6 KG of UV ink/resin from its Epson-brand head in glorious full color and layers as small as 10 um. The ink isn’t super cheap — the CMYK kit looks to MRSP at 189 USD — but you aren’t locked in to expensive cartridges at least. HayGears sells ink in bottles, and you’re free to grab any other brand’s bottles if you want to risk it.

The Kickstarter is ongoing, and it will be some time before backers get their printers. But we can report that the early review copies, like the one [Steve Makes Everything] got for the video embedded below, seem to live up to the manufacturer’s claims, which is promising indeed. Certainly the idea of SLA quality without the mess is very appealing to many — though the super-early-bird price of two grand on Kickstarter and the doubtless higher MRSP may temper some of that interest.

If you’re curious about this UV printer business and why a maker might want one that doesn’t do 3D, our own [Tom Nardi] went hands-on with the EufyMake E1 last year.

Continue reading “UV Printer? 3D Printer? HeyGears Says “Why Not Both”?”

Bike Trainers As Video Game Controllers

While we’ve largely settled on analog sticks and digital buttons for controlling video games, there’s all sorts of projects to create truly esoteric controllers that allow playing games in unique ways. This one from [sukolupo] lets you use data from standard bike trainers to get your virtual character moving.

Called Deck de France, it maps the data coming from one of the supported bike trainers to a virtual controller which can then be “plugged in” to a gaming console of choice, in this case a Steam Deck mounted to the trainer’s handlebars. Although a bike trainer doesn’t have the same number of inputs as a modern gaming controller, it does have enough to play games like Rocket League. As you might expect, it’s also perfect for biking titles such as the Tour de France series.

As far as unique controllers for video games go, this one is surely up in the rankings with a real trombone or a controller purpose-built for riding virtual horses. It’s also a great way for those who are getting a bit bored of riding their trainers to breathe some new life into their exercise routine. We’ve also seen some open-source alternatives for modern bike trainer software as well, which is another great way to get excited about exercise equipment too.

Stewart Platform Walker Gains Feeling In Legs From Resistors

Stewy is a very interesting robot, with some slightly odd kinematics. Its head is a Stewart platform, which is a common-enough 6-DOF actuated plate normally used with a fixed base. By connecting legs to the same servos running the Stewart platform, [JD] turned it into an adorable hexapod walker. The walker had a problem, though: it can’t feel its feet, and [JD] thinks that would make it much more mobile on uneven surfaces. So he got some resistors to turn the cheap servos in its legs into force-sensing actuators.

Well, almost. He’s not actually putting strain gauges or anything like that into the legs; he’s just measuring the voltage drop across a resistor in series with the servos. Since the motors draw more current the more torque they’re putting out, he has a very quick and easy way to sense the current and thus the torque using good old Ohm’s law and an analog input on the microcontroller driving the robot. It’s a simple hack, but the data he’s getting is surprisingly good for how much work it is to add to a robot, as you can see in the video — at least once he slowed down the servos a touch.

Perhaps this isn’t a ground-breaking innovation, but [JD] does a very good idea explaining it. Of course if you want to use resistors to sense force directly, force-sensitive resistors are a thing that we’ve seen in everything from Twister-mat MIDI controllers to self-leveling 3D printers.

Continue reading “Stewart Platform Walker Gains Feeling In Legs From Resistors”