Pulse Oximetry Sensor Judges Your Coffee Roast

October 22, 2020 by Donald Papp 24 Comments

Breakout board for the MAX30101, which [Zach] used as the basis of his roast gauge. The sensor is at the top edge of the board.

Parts designed and marketed for a specific application can nevertheless still be useful in other ways, and whenever that happens, it’s probably the start of a pretty good hack. Using a sensor for something other than its intended purpose is exactly what [Zach Halvorson] did to make the Roast Vision device, which uses the MAX30101, a sealed optical sensor intended mainly for pulse oximetry and heart-rate monitoring.

[Zach] is instead using that sensor to measure the roast level of coffee beans, and assign a consistent number from 0 to 35 to represent everything from Very Dark to Very Light. Measuring a bean’s roast level is important to any roaster seeking accuracy and consistency, but when [Zach] found that commercial roast gauges could easily cost over a thousand dollars, he was sure he could do better.

[Zach] settled on using a Sparkfun MAX30101 breakout board to develop his device, and Sparkfun shared an informative blog post that demonstrates how making hardware and tools more accessible can help innovative ideas flourish. The Roast Vision device has a 3D printed enclosure, and a simple top-loading design with an integrated sample cup makes it easy to use. One simply puts about a teaspoon of finely-ground coffee into the sample cup, and the unit provides a measurement in a couple of seconds. Fortunately the sensor works just fine though an acrylic window which means the device can be sealed; a handy feature for a tool that will spend a lot of time around ground coffee.

The joys of fresh roasted coffee is something that is perfectly accessible to those making small batches at home. There are commercial options for small roasters of course, but should you wish to go the DIY route, check out our own Elliot Williams’ guide on making a low-cost DIY roaster.

WiFi Hacking Mr. Coffee

September 29, 2020 by Adam Zeloof 42 Comments

You wake up on a Sunday, roll out of bed, and make your way to the centerpiece of your morning, the magical device that helps you start your day: the coffee machine. You open the companion app, because everything has an app in 2020, and select a large latte with extra froth. As you switch open a browser to check Hackaday, the machine beeps. Then the built-in grinder cranks up to 100, the milk frother begins to whir, and the machine starts spraying water. Frantic, you look at the display for an error code and instead see a message instructing you to send $75 to a bitcoin wallet, lest your $300 machine become a doorstop.

Outlandish though it may seem, this has become quite a real possibility, as [Martin Hron] at the Avast Threat Labs demonstrates. In fact, he could probably make your modern macchiato machine do this without setting foot in your house (so long as it comes with a built-in ESP8266, like his did).

Building on others’ work that identified the simple commands that control the machine over it’s WiFi connection (nothing says “brew me a nice cup o’ joe” like 0x37), [Martin] reverse-engineered the Smarter Coffee companion app to extract and reverse engineer its firmware. He was actually able to find the entire firmware image packaged within the app- relatively uncommon in the world of Over-The-Air (OTA) updates, but convenient in this case. Using Interactive Disassembler (IDA) to sift through the firmware’s inner workings, he identified the functions that handle all basic operations, including displaying images on the screen, controlling the heating elements, and of course, beeping. From there, he modified the stock firmware image to include some malicious commands and ran an OTA update.

The mind-boggling part here is that not only was the firmware transmitted as unencrypted plaintext over unsecured WiFi, but the machine didn’t even require a user to confirm the update with a button press. With one quick reboot, the trap was set. The machine operated normally, while waiting for “Order 66,” causing it to turn all the heating elements on, spool up the built-in grinder, and beep. Constantly.

While a broken coffee machine seems relatively innocuous, there are some pretty significant lapses in hardware/firmware security here that, while avoidable, almost seem unnecessary in the first place. It makes us wonder- why does Mr. Coffee need a smartphone in the first place?

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Graphene Prints More Smoothly Under The Influence Of Alcohol

August 22, 2020 by Kristina Panos 10 Comments

If you’ve ever sloshed coffee out of your mug and watched the tiny particles scurry to the edges of the puddle, then you’ve witnessed a genuine mystery of fluid mechanics called the coffee ring effect. The same phenomenon happens with spilled wine, and with functional inks like graphene.

Graphene and other 2D crystals print much better under the influence of alcohol.

The coffee ring effect makes it difficult to print graphene and similar materials onto silicon wafers, plastics, and other hard surfaces because of this drying problem. There are already a few commercial options that can be used to combat the coffee ring effect, but they’re all polymers and surfactants that negatively affect the electronic properties of graphene.

Recently, a group of researchers discovered that alcohol is the ideal solution. In the case of spilled graphene, the particles fleeing for the edges are naturally spherical. By adding a mixture of isopropyl and 2-butanol alcohol, they get flattened into a pancake shape, resulting in smoother deformation during the drying process and an easier printing process with better results.

Graphene is quite interesting by nature, and has many uses. It can shift from an insulator to a superconductor with the right temperature changes, and it can desalinate sea water for drinking.

Something’s Brewing Up In The Woods – And It Looks Stunning

August 17, 2020 by Sven Gregori 9 Comments

Caffeine fuels the hacker, and there are plenty of options to get it into your system, from guzzling energy drinks to chewing instant coffee pellets. But let’s take a nice cup of coffee as input source, which itself can be prepared in many ways using all kinds of techniques. In its simplest form, you won’t need any fancy equipment or even electricity, just heat up some water over a fire and add your ground beans to it. This comes in handy if you’re camping out in the woods or find yourself in a post-apocalyptic world, and in case you still prefer a stylish coffee maker in such a situation — why let an apocalypse ruin having nice things? — you’re in luck, because [Andreas Herz] designed this nifty looking off-the-grid coffee maker.

The design somewhat resembles a certain high-end precision coffee maker that even fictional billionaires approve of, which [Andreas] created in Fusion 360 and is available online. The device base is made from brass, wood, and silicone he cast from a 3D printed mold, while the glass and ceramic parts — i.e. the water tank and coffee pot — are simply store bought. [Andreas] opted for fuel gel as heat source, which burns under a copper coil that acts as heat exchanger and starts the actual brewing process. It took him a few attempts to get it right, and in the end, a coat of black exhaust paint did the trick to get the temperatures high enough.

This may not be the fastest coffee maker, as you will see in the video after the break, but choosing a different fuel source might fix that — [Andreas] just went the safe(r) way by using fuel gel here. But hey, why rush things when you’re camping or having a cozy time in a cabin anyway. Now all you need is the right blend, maybe even your own, made with a camp stove coffee roaster. Of course, in case of an actual apocalypse, you may not have easy access to a CNC router or 3D printer, but then there’s always the option to build an espresso machine from salvaged motorcycle parts.

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Wobble Disk Coffee Roaster Gets The Beans Just Right

July 23, 2020 by Lewin Day 16 Comments

Coffee roasting is an art or a science, depending on who you talk to. Both camps will however agree that attention to detail is key. Many diehard beanheads, as they’re known, will go so far as to create their own roasting hardware to get the job done just right. [Larry Cotton] is one such builder, who has created an elegant roaster to get his brew just right.

The build is based around a wobble disk design. This consists of a round plate fixed at a 45-degree angle to a rotating shaft. As the shaft spins, the disk gently sweeps and agitates the roast, allowing the batch to heat up evenly without burning the beans. It’s a two-part design, with heat gun parts in the base to generate the hot air for the roasting process. The bean basket sits on top, held in place by magnets that also act as a conduit for the wobble disk motor’s power supply.

It’s a tidy build, which allows for accurate roasting and easy dumping of the beans once finished. If you’re a serious beanhead yourself with a few hacks up your sleeve, be sure to let us know! Video after the break.

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DIY Hand Mixer Whips Coffee Into Shape

June 27, 2020 by Kristina Panos 13 Comments

Along with the substantial rise in bread baking over the last few months, many people have been whipped into a frenzy over this tasty-looking frothy coffee beverage called Dalgona. It’s like a caffeinated meringue made from instant coffee, sugar, boiling water, and a whole lot of air that is then spooned onto milk or milk and ice.

Sure, you can use a whisk to mix it up if you don’t mind doing so continuously and vigorously for at least a full three minutes. [HimanshuS8] quickly got tired of making his wife’s coffee this way, and designed a small electric hand mixer especially for this task. [HimanshuS8] happens to be a hardware design engineer, which is why it looks so minimalist and beautiful.

The inside is just as beautiful, mixing junk bin parts like the 6 V motor from a cassette deck with printed gears and beaters. At the risk of reviving an old debate, we hope [HimanshuS8] used food-safe filament for those. If you replicate this, you could try to design it around standard metal beaters instead. Check out the demo after the break while you wait for the water to boil.

Coffee makes everything better, including 3D prints — the high cellulose content in coffee waste has been shown to drastically improve print strength.

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Impressive Lever-Press Espresso Machine Has Finesse

April 8, 2020 by Kristina Panos 8 Comments

Some people will do anything for a good cup of coffee, and we don’t blame them one bit — we’ve been known to pack up all our brewing equipment for road trips to avoid being stuck with whatever is waiting in the hotel room.

While this stylish lever-based industrial coffee machine made by [exthemius] doesn’t exactly make textbook espresso, it’s pretty darn close. Think of it like an Aeropress on steroids, or more appropriately, bulletproof coffee. As you can see in the demo after the break, the resulting coffee-spresso hybrid brew looks quite tasty.

Here’s how it works: finely-ground beans go in a pressurized portafilter basket that was scavenged from an entry-level prosumer espresso machine. Pour boiling water into the top of the cylinder, and pull the giant lever down slowly to force it through the portafilter. Presto, you’re in thin, brown flavor town.

We love the piston-esque plunger that [exthemius] made by layering washers and rubber gaskets up like a tiramisu. Although there are no plans laid out, there’s probably enough info in the reddit thread to recreate it.

If you ever do find yourself stuck with hotel house brand, soak it overnight to make it much more palatable.

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