Perfect Cheese Every Time With This Temperature Controller

August 24, 2019 by Jenny List 13 Comments

Anyone who is from a background in which cheesemaking is a feature will tell you that it is an exact science in which small differences in parameters can make a huge difference in the resulting cheese, to the extent that entire batches can be rendered inedible. In particular the temperature at which the milk is held can be crucial to the production of individual styles of cheese. A friend of [William Dudley]’s had this problem, as a dairy farmer and artisinal cheesemaker they had to carefully control their vat with a set of profiles depending upon the recipe in use. This was achieved using an Arduino Mega 2650 and a thermocouple to control the heat source for the hot water in the outer wall of the vat.

A cheap K-type thermocouple amplifier proved unsatisfactory, so a Sparkfun item was substituted. A relay, Ethernet adaptor, and LCD display provided power control, access to a web interface, and user feedback respectively. Four buttons to select programs were added, and the whole was neatly boxed up to survive the dairy and put to work. In tests with a saucepan it was configured as a PID controller, but the real vat proved to have a much greater thermal inertia so a simpler bang-bang home thermostat style approach was used. Temperatures are logged in an eeprom for later retrieval via the web interface.

We don’t see the cheeses produced, but we’re sure they must be worth the effort. Blessed may be the cheesemakers, but doubly blessed are they who have a little help from an Arduino.

UbaBOT Mixes Up 50 Cocktails To Quench CCCamp Thirst

August 22, 2019 by Mike Szczys 11 Comments

[Steffen Pfiffner’s] tent during the Chaos Communication Camp is full of happiness delivered by something greater than alcohol alone. He’s brought a robot bartender that serves up a show while mixing up one of about 50 cocktail recipes.

The project is the work of five friends from Lake Constance (Bodensee) in southern Germany, near the borders with Switzerland and Austria. It started, as many projects do, with some late night drinking. The five were toiling to mix beverages more complex than your most common fare, and decided to turn their labors instead to robot making.

Since 2012, the project has gone through five revisions, the most recent of which the team calls Uba BOT. Delightfully, the cup tray which moves left and right on the front of the machine is connected using a strain gauge. This provides a way for the robot to sense the presence of a cup to avoid dispensing ingredients all over the bar itself. It also provides a feedback loop that verifies the amount of liquids and volume of ice added to the cup. Once everything’s in the cup, a rotary milk frother lowers itself into position to stir things up a bit.

A Raspberry Pi is in control of eighteen pumps that dispense both liquor and mixers. The team is still trying to work out a way to reliably dispense carbonated mixers, which so far have been a challenge due to over-excited foam. The software was originally based on Bartendro, but has since taken on a life of its own as these things often do. The first time you want a drink, you register an RFID tag and record your height, weight, and age which keeps track of your estimated blood alcohol content based on time and your number of visits to the robot. The firmware also tracks the state of each ingredient to alert a meat-based bar attendant of when a bottle needs replacing.

Join us after the break to see an explanation of what’s under the hood and to watch Uba BOT mix up a Mai Tai.

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Preserved Lemons On A Hacker’s Budget

August 6, 2019 by Brian McEvoy 15 Comments

“If you wish to make an apple pie from scratch, you must first invent the universe.” [Carl Sagan]. If you wish to make preserved lemons the same way as [Uri Tuchman], you have to start with that mentality. Video also below. The recipe for [Uri]’s preserved lemons involves two ingredients ~~see~~ sea salt, and sliced lemons, but we don’t expect you came here looking for a recipe and the food is less important than the journey.

Recipes take for granted that we have all the necessary utensils on hand, but what if you are missing one? What if you are missing all of them? Life’s lemons won’t get the best of us, and if we’re utensil-poor and tool-rich we will make those lemons regret trying to take a bite out of us. The first fixture for cutting lemons is a cutting board, then a knife, and finally an airtight container. We see him make all of them from stock material by hand. Does that seem like a lot of work? You forgot that if you’re going to eat up, you’ll need a serving platter and fork. If he ever opens a restaurant, don’t expect it to be fast food.

Maybe humans will only need one tool in the kitchen someday but at least one cat receives food from a single silicone-brained tool.

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Put A Smoke Detector To Some Use

July 30, 2019 by Bryan Cockfield 29 Comments

While we’re certainly not denying that smoke detectors are useful, there’s a certain kind of tragedy to the fact that most of them will never realize their true purpose of detecting smoke, and alerting us to a dangerous fire. On the other hand, [Ben] really unlocks the potential hidden deep in every smoke detector with his latest project which uses the smoke-detecting parts of a smoke detector to turn on the exhaust fan over his stove.

The project didn’t start with the noble aim of realizing the hidden and underutilized quiescent nature of a smoke alarm, though. He wanted his range exhaust fan to turn on automatically when it was needed during his (and his family’s) cooking activities. The particular range has four speeds so he wired up four relays to each of the switches in the range and programmed a Particle Photon to turn them on based on readings from an MQ-2 gas-detecting sensor.

The sensor didn’t work as well as he had hoped. It was overly sensitive to some gasses like LPG which would turn the range on full blast any time he used his cooking spray. Meanwhile, it would drift and not work properly during normal cooking. He tried disabling it and using only a temperature sensor, which didn’t work well either. Finally, he got the idea to tear apart a smoke detector and use its sensor’s analog output to inform the microcontroller of the current need for an exhaust fan. Now that that’s done, [Ben] might want to add some additional safety features to his stovetop too.

Making Instant Ramen A Bit More Instant

July 21, 2019 by Jenny List 32 Comments

Instant ramen, the favoured repast of the impecunious would-be tech genius! It’s cheap, of dubious nutritional value, and it only takes a minute to cook. But what if you are in the creative Zone to the extent that five minutes to boil water is too much? For that you need an automatic ramen cooker, which is what [Mayermakes] has created from an upcycled electric filter coffee maker.

A filter coffee maker is a surprisingly effective instant ramen cooker without modification, in that it already contains a hotplate and water boiler to dribble hot water on some noodles. But it lacks any means of adding the seasoning or the essential hot sauce, so he created a 3D-printed rotating hopper driven by a stepper motor, and a servo driven syringe, while coffee maker itself is given a solid state relay to switch it on.

Controlling the show is an Arduino MKR board, which serves up a web interface with the option of ramen as it comes, or ramen with hot sauce. The result is an automated pot of $0.49 noodles that will set no gourmet’s heart a-flutter. Then again, fine dining is not why instant ramen exists.

This appears to be our first ramen-cooking coffee pot, but we have seen a guitar made from noodles!

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Syringe Pump Turns CNC Machine Into A Frosting Bot

June 28, 2019 by Dan Maloney 3 Comments

“Amazing how with only the power of 3D-printing, two different computers, hundreds of dollars in CNC machinery, a lathe, and modern microcontroller magic, I can almost decorate a cupcake as well as a hyperactive ten-year-old.” We can think of no better way to sum up [Justin]’s experiment in CNC frosting application, which turns out to only be a gateway to more interesting use cases down the road.

Granted, it didn’t have to be this hard. [Justin] freely admits that he took the hard road and made parts where off-the-shelf components would have been fine. The design for the syringe pump was downloaded from Thingiverse and does just about what you’d expect – it uses a stepper motor to press down on the plunger of a 20-ml syringe full of frosting. Temporarily attached in place of the spindle on a CNC router, the pump dispenses onto the baked goods of your choice, although with an irregular surface like a muffin top the results are a bit rough. The extruded frosting tends to tear off and drop to the surface of the cake, distorting the design. We’d suggest mapping the Z-height of the cupcake first so the frosting can dispense from a consistent height.

Quality of the results is not really the point, though. As [Justin] teases, this hardware is in support of bioprinting of hydrogels, along with making synthetic opals. We’re looking forward to those projects, but in the meantime, maybe we can all just enjoy a spider silk beer with [Justin].

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The Quest For Perfect Croissants Via A DIY Dough Sheeter

June 22, 2019 by Lewin Day 24 Comments

Baking is a wonderful pastime, as much an art as a science. [Alex] pursues the craft with plenty of vigor, and had built his very own dough sheeter to assist in his work. Unfortunately, the design had several flaws, and came out of a recent move rather the worse for wear. Growing tired of having to deal with dough of inconsistent thickness, he went back to the drawing board to whip up a new version (Youtube link, embedded below).

The new model improves significantly over the predecessor, by directly addressing the engineering pitfalls of the first design.

The core of the machine is a moving platform combined with a rolling pin, that can be set to a desired height to roll the dough into a set thickness. This is key to baking top-notch croissants, which [Alex] takes very seriously. His initial model used a table leg for a rolling pin, fitted with a threaded rod down the centre. This had significant issues with both runout, and uneven diameter across its length. Additionally, its frame had not held up after a recent move, and [Alex] was keen to start again.

The new model starts with attention paid to the basic engineering issues. The table leg is replaced with a professional-grade rolling pin, fitted with 3D-printed gears that accurately align the axis of rotation to the centre of the pin. A rack and pinion drive is also added to move the dough platform. Finally, a locking pin system is used to set the desired height of the dough.

It’s a useful project for the keen baker, and one that leans heavily on additive manufacturing methods. Producing such a tool in the years before 3D printers would have required significant effort to produce the required gears and mating components, so it’s impressive to see how easily something like this can come together these days. A hacker mindset can always be handy for baking – don’t forget, you can improve your bread crusts with steam! Video after the break.

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