inside shot of a refrigerator with water bulk tank and seltzer pump

Continuous Seltzer Deployment System Solves Our Bubbly-Water Sourcing Problems

October 1, 2018 by Brian Boucheron 19 Comments

Seltzer water – that bubbly, carbonated water that disappoints sugar-craving children everywhere – has experienced a steady rise in popularity over the past few years. This is perhaps partly fueled by the availability of countertop carbonators such as the SodaStream.

Not satisfied with the tedious and pedestrian process of manually carbonating individual bottles of water, [piyoman] has instead built a tidy little tap of unlimited cold, filtered seltzer. It’s no easy gag. The build uses a commercial carbonator pump, reverse osmosis water filter, bulk tank, and a standard CO2 cylinder to create a constant source of carbonated water. Most of this setup is stuffed into a dorm-sized fridge (tetris-style) and topped with a fancy beer faucet to dispense the resulting bubblewater.

At roughly $800 for the documented system, you need to have a great reason to build your own. But [piyoman] provides detailed instructions, a parts list, and suggestions for cost savings and future improvements if you do take on a system like this for your seltzer needs.

Cheaper Carbonation Options

While looking at how DIY carbonation has been done in the past we found [Richard Kinch’s] Carbonating at Home with Improvised Equipment and Soda Fountains page which dives into many other options. His site – a wonderful, dense demonstration of the beauty of “web 1.0” – walks through the basics of carbonated water, discusses CO2 tanks and gauges, and shows how to build a simple carbonation cap for making seltzer in standard PET soda bottles.

Maker Faire NY: Cocoa Press Chocolate Printer

September 29, 2018 by Tom Nardi 11 Comments

If you haven’t figured it out by now, the hype over desktop filament printers is pretty much over. But that doesn’t mean there aren’t new avenues worth exploring that use the basic FDM printer technology. If anything, the low cost and high availability of 3D printer parts and kits makes it easier to branch off into new territory. For example, experimenting with other materials which lend themselves to being “printed” layer by layer like a thermoplastic. Materials such as cement, clay, or even chocolate.

[Ellie Weinstein] brought her Cocoa Press printer to the 2018 World Maker Faire in New York, and we have to say it’s a pretty impressive piece of engineering. Hackers have been known to throw a syringe-based paste extruder onto a regular 3D printer and try their luck with squirting out an edible object from time to time, but the Cocoa Press is truly a purpose built culinary machine.

Outwardly it features the plywood case and vaguely Makerbot-looking layout that we’ve seen plenty of times before in DIY 3D printers. It even uses the same RAMPS controller running Marlin that powers your average homebrew printer. But beyond these surface similarities, the Cocoa Press has a number of purpose-built components that make it uniquely qualified to handle the challenges of building with molten chocolate.

For one, beyond the nozzle and the walls of the syringe, nothing physically comes into contact with the chocolate to be printed; keeping the mess and chance of contamination to a minimum. The leadscrew actuated plunger used in common paste extruders is removed in favor of a purely air powered system: a compressor pumps up a small reservoir tank with filtered and dried air, and the Marlin commands which would normally rotate the extruder stepper motor are intercepted and used to trigger an air valve. These bursts of pressurized air fill the empty area above the chocolate and force it out of the 0.8 mm nozzle.

In a normal 3D printer, the “melt zone” is tiny, which allows for the heater itself to be relatively small. But that won’t work here; the entire chocolate load has to be liquefied. It’s a bit like having to keep a whole roll of PLA melted during the entire print. Accordingly, the heater on the Cocoa Press is huge, and [Ellie] even had a couple spare heaters loaded up with chocolate syringes next to the printer to keep them warm until they’re ready to get loaded up.

Of course, getting your working material hot in a 3D printer is only half the battle, you also need to rapidly cool it back down if you want it to hold its shape as new layers are placed on top of it. A normal 3D printer can generally get away with a little fan hanging next to the nozzle, but [Ellie] found the chocolate needed a bit of a chill to really solidify.

So she came up with a cooling system that makes use of water-cooled Peltier units. The cold side of the Peltier array is inside a box through which air is forced, which makes its way through an insulated hose up to the extruder, where a centrifugal fan and 3D printed manifold direct it towards the just-printed chocolate. She reports this system works well under normal circumstances, but unusually high ambient temperatures can overwhelm the cooler.

While “the man” prevented show goers from actually eating any of the machine’s creations (to give out food in New York, you must first register with the city), they certainly looked fantastic, and we’re interested in seeing where the project goes from here.

Tracking The Office Coffee Machines Using Current Draw

August 24, 2018 by Steven Dufresne 16 Comments

Coffee is the lifeblood of hackers, IT workers, and apparently, IT workers who are also hackers. [Omerfarukz] is clearly the latter. He works as part of a large team spread over multiple floors, all with coffee machines, any one of which is fair game. The problem is knowing which one has coffee that is ready to pour. He needed a non-invasive way to monitor the coffee machines.

After contemplating a few solutions, he opted for one which wouldn’t offend the coffee gods. The machines use a high current to produce their heat, so he adapted some old remote control power sockets for the machines to plug into which would now monitor the current. A high current means the coffee is brewing and he knew that brewing takes one minute per cup, so the duration of the high current tells him the number of cups.

Having had no success with a current sensing transformer, he opted for an ACS712 chip, at heart a Hall effect sensor which outputs a voltage proportional to the test current. That goes to the IO pins of an ATtiny, and from there via serial to an ESP8266 and thence to Google Firebase for processing and notifying of IT workers in need of stimulation. For those wishing to partake, he’s posted the circuit on Github.

We’ve seen a few other non-invasive ways to do this monitoring. For example, there’s weighing the machines using a bathroom scale and the more manual phone-notifying alarm button.

Digital Dining With Charged Chopsticks

August 16, 2018 by Brian McEvoy 14 Comments

You step out of the audience onto a stage, and a hypnotist hands you a potato chip. The chip is salty and crunchy and you are convinced the chip is genuine. Now, replace the ordinary potato chip with a low-sodium version and replace the hypnotist with an Arduino. [Nimesha Ranasinghe] at the University of Maine’s Multisensory Interactive Media Lab wants to trick people into eating food with less salt by telling our tongues that we taste more salt than the recipe calls for with the help of electrical pulses controlled by everyone’s (least) favorite microcontroller.

Eating Cheetos with chopsticks is a famous lifehack but eating unsalted popcorn could join the list if these chopsticks take hold and people want to reduce their blood pressure. Salt is a flavor enhancer, so in a way, this approach can supplement any savory dish.

Smelling is another popular machine hack in the kitchen, and naturally, touch is popular beyond phone screens. You have probably heard some good audio hacks here, and we are always seeing fascination stuff with video.

Internet Of Tea: Coaster Watches For Optimum Drinking Temperature

August 14, 2018 by Dan Maloney 3 Comments

Ah, the age-old question: at what temperature does one’s tea need to be for maximum enjoyment? It’s subjective, of course, but subjective in a way that makes everyone else’s opinion demonstrably wrong. What’s worse, the window of opportunity for optimum tea temperature is extremely narrow. What’s a tea drinker to do?

Throw a little technology at the problem, of course, in the form of this Internet of Tea smart coaster. Through careful experimentation, [Benjojo] determined the temperature of his favorite mug when the tea within was just right for drinking and designed a coaster to alert him to that fact. The coaster is 3D-printed and contains an MLX90616 IR temperature sensor looking up at the bottom of the mug. An ESP8266 lives inside the coaster too and watches for the Optimum Tea Window to open, sending an alert via Discord when the time is right. Yes, he admits that a simple blinking LED on the coaster would keep his tea habit metadata from being slurped up by the international tea intelligence community, but he claims he has nothing to hide. Good luck with that.

What’s next for [Dane]’s tea preparation? Perhaps he can close the loop and automate the whole pre-consumption process.

Carousel Of Cereals Mixes And Matches Custom Breakfast Blends

June 28, 2018 by Dan Maloney 10 Comments

There are those who reckon the humble bowl of breakfast cereal to be the height of culinary achievement. Look askance if you must, but cereal junkies are a thing, and they have a point. The magic comes not from just filling a bowl and adding a splash of milk, but by knowing which cereals to mix together.

Who needs all that fussy mixing, though, when you can automate and customize your cereal dispensing chores? That’s the approach [Kevin Obermann] and [Adrian Bernhart] took with their Cereal Dispensing Machine, even if they went a little further than necessary. Laser-cut plywood forms a four-station carousel for off-the-shelf dry-good dispensers, each of which got a stepper motor to replace the wrist-twisting. The original motors were a bit too wimpy to handle the more rugged morning selections and were eventually upgraded to gear motors. The platform that supports the dispensers also holds all the electronics, including an ESP32 to run everything and host the web app needed to choose your poison. Plus RGB LEDs, because breakfast should look like a rave. Sadly, the team ran out of GPIO pins and were unable to run the peristaltic pump needed to add the milk. There will always be version 2.0, though.

If cereal isn’t your automated breakfast of choice, we understand. Perhaps a more [Wallace] and [Gromit] style breakfast machine would do, or a robotic peanut butter sandwich any time of day is a treat.

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Raspberry Pi Tracks Starter Fermentation For Optimized Sourdough

June 27, 2018 by Dan Maloney 8 Comments

Those of you who’ve never had a real sourdough have never had real bread. Good food fights back a little when you eat it, and a proper sourdough, with its crispy crust and tangy center, certainly fits the bill. Sourdough aficionados, your humble writer included, all have recipes that we pretend are ancient family secrets while in reality we’re all just guessing. Sourdough is partly science, partly art, but mostly delicious black magic.

In an effort to demystify his sourdough process, [Justin Lam] has gone digital with this image processing sourdough starter monitor. Sourdough breads are leavened not by the addition of brewers yeast (Saccharomyces cerevisiae), but by the inclusion of a starter, a vibrant ecosystem of wild yeasts that is carefully nurtured, sometimes for years. Like any other living thing, it needs to be fed, a task that should happen at the point of maximum fermentation. Rather than guess when this might be, [Justin] used a Raspberry Pi Zero and PiCam to capture a time-lapse video of the starter as the beasties within give off their CO₂, thus expanding it up inside its container. A little Python does the work of thresholding and finding the top of the starter as it rises, allowing [Justin] to plot height of the starter over time. He found that peak height, and therefore peak fermentation, occurs about six hours after feeding. He has used his data to better inform his feeding schedule and to learn how best to revive neglected starters.

Surprisingly, this isn’t the first time we’ve discussed sourdough here. It seems that someone uses Git for iterative sourdough recipe development, and we once featured a foundry made from a pyrolyzed loaf of sourdough.

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