A Gaggia classic espresso machine with an LCD screen attached to the top, sitting on a table with vase of yellow lily flowers to its left and sunlight coming in from a window from the right.

Homebrew Espresso Maker Modding With Gaggiuino

For those that don’t know, Gaggia is a company that produces a line of affordable “entry-level” espresso coffee makers that offer good quality consumer espresso machines at reasonable prices. The entry level machines don’t offer fine grained control over temperature, pressure and steam which is where the Gaggiuino project comes in.

A schematic of the Gagguino project

The Gaggiuino project is an “after market” modification of many espresso makers, such as the Gaggia classic and Gaggia classic pro. The main additions are a MAX6675 thermocouple module paired with a K-Type thermocouple sensor for closed loop control over the temperature. Options for adding an AC dimmer module that attaches to the pump motor and a 0 Mpa to 1.2 Mpa ranged XDB401 pressure sensor, installed in line between the pump and the boiler, provide further closed loop control over the pressure and flow profiling.

Load cells can be attached to the drip tray to allow for feedback about the pour weight with a Nextion 2.4″ LCD touchscreen provides the user interface for profile selection and other interactivity. The project offers a “base” modification using an Arduino Nano as the microcontroller, in line with its namesake, but has an option for an STM32 Blackpill module that can provide more functionality beyond the scope of the Nano.

The Gaggiuino project is open source with code and extensive documentation available on GitHub. There is also a Discord community for those wanting help with their build or that have the inclination to share their passion for DIY espresso modding with the Gaggiuino. Espresso machine hacks are a favorite of ours and we’ve featured many projects on espresso machine builds and mods ranging from PID control of classic espresso makers to beautifully minimal closed loop homebrew espresso machines.

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Using Statistics Instead Of Sensors

Statistics often gets a bad rap in mathematics circles for being less than concrete at best, and being downright misleading at worst. While these sentiments might ring true for things like political polling, it hides the fact that statistical methods can be put to good use in engineering systems with fantastic results. [Mark Smith], for example, has been working on an espresso machine which can make the perfect shot of coffee, and turned to one of the tools in the statistics toolbox in order to solve a problem rather than adding another sensor to his complex coffee-brewing machine.

To make espresso, steam is generated which is then forced through finely ground coffee. [Mark] found that his espresso machine was often pouring too much or too little coffee, and in order to improve his machine’s accuracy in this area he turned to the linear regression parameter R2, also known as the coefficient of determination. By using a machine learning algorithm tuned to this value, which assesses predictable variation in a data set, a computer can more easily tell when the coffee begins pouring out of the portafilter and into the espresso cup based on the pressure and water flow in the machine itself rather than using some other input such as the weight of the cup.

We have seen in the past how seriously [Mark] takes his coffee-making, and this is another step in a series of improvements he has made to his equipment. In this iteration, he has additionally produced a simulation in JupyterLab to better assist him in modeling the system and making even more accurate predictions. It’s quite a bit more effort than adding sensors, but since his espresso machine already included quite a bit of computing power it’s not too big a leap for him to make.

Extreme Espresso, Part 2: An Inductive Water Level Sensor

[Mark Smith] must really, really like his coffee, at least judging by how much effort he’s put into tricking out his espresso machine.

This inductive water tank sensor is part of a series of innovations [Mark] has added to his high-end Rancilio Silvia machine — we assume there are those that would quibble with that characterization, but 800 bucks is a lot to spend for a coffee maker in our books. We recently featured a host of mods he made to the machine as part of the “Espresso Connect” project, which includes a cool Nixie tube bar graph to indicate the water level in the machine. That display is driven by this sensor, the details of which [Mark] has now shared. The sensor straddles the wall of the 1.7-liter water tank, so no penetrations are needed. Inside the tanks is a track that guides a copper and PETG float that’s sealed with food-safe epoxy resin.

Directly adjacent to the float track on the outside of the tank is a long PCB with a couple of long, sinuous traces. These connect to an LX3302A inductive sensor IC, which reads the position of the copper slug inside the float. That simplifies the process greatly; [Mark] goes into great detail about the design and calibration of the sensor board, as well as hooking it into the Raspberry Pi Zero that lies at the heart of “Espresso Connect’. Altogether, the mods make for a precisely measured dose of espresso, as seen in the video below.

We’d say this was maybe a bit far to go for the perfect cup of coffee, but we sure respect the effort. And we think this inductive sensor method has a lot of non-caffeinated applications that probably bear exploration.

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3D Printing Espresso Parts

Virtually any hobby has an endless series of rabbit holes to fall into, with new details to learn around every corner. This is true for beekeeping, microcontrollers, bicycles, and gardening (just to name a few), but those involved in the intricate world of coffee roasting and brewing turn this detail dial up to the max. There are countless methods of making coffee, all with devout followers and detractors alike, and each with its unique set of equipment. To explore one of those methods and brew a perfect espresso, [Eric] turned to his trusted 3D printer and some compressed gas cylinders.

An espresso machine uses high pressure to force hot water through finely ground coffee. This pressure is often developed with an electric pump, but there are manual espresso machines as well. These require expensive parts which can withstand high forces, so rather than build a heavy-duty machine with levers, [Eric] turned to compressed CO2 to deliver the high pressure needed.

To build the pressure/brew chamber, he 3D printed most of the parts with the exception of the metal basked which holds the coffee. The 3D printed cap needs to withstand around nine atmospheres of pressure so it’s reasonably thick, held down with four large bolts, and holds a small CO2 canister, relief valve, and pressure gauge.

To [Eric]’s fine tastes, the contraption makes an excellent cup of coffee at minimal cost compared to a traditional espresso machine. The expendable CO2 cartridges only add $0.15 to the total cost of the cup and for it’s simplicity and small size this is an excellent trade-off. He plans to improve on the design over time, and we can’t wait to see what he discovers. In the meantime, we’ll focus on making sure that our beans are of the highest quality so they’re ready for that next espresso.

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Impressive Lever-Press Espresso Machine Has Finesse

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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Make That Special Cup Of Coffee By Completely Tweaking The Coffee Machine

An interesting part of working on the Building Management and Control (BMaC) project – as previously covered on this site – was the reverse-engineering and ultimately the gaining of full control over the coffee machines at the office. Not the boring filter coffee machines, mind you, but the fully automatic espresso machine type that grinds beans, makes coffee, adds milk, and much more. Depending on one’s budget, naturally.

These little marvels of engineering contain meters of tubing, dozens of sensors, valves, ceramic grinders, and heating elements. The complexity of this machinery made us think that maybe there was more that we could do with these machines beyond what their existing programming and predefined products would allow. Naturally, there was.

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Will Hack For Espresso

[Avidan Ross] has an unyielding passion for coffee. Brewing a proper espresso is more than measuring fluid ounces, and to that end, his office’s current espresso machine was not making the cut. What’s a maker to do but enlist his skills to brew some high-tech coffee.

For a proper espresso, the mass of the grounds and the brewed output need to be precisely measured. So, the office La Marzocco GS3 has been transformed into a closed-loop espresso machine with a Particle Photon and an Acaia Lunar waterproof scale at its heart.

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