Why Make Coffee When You’re Tired? Let A Robot Do It For You

July 25, 2021 by Kristina Panos 9 Comments

Like us, [Alberto] doesn’t compromise when it comes to a good cup of coffee. We figure that if he went to an office in the Before Times, he was the type of coworker to bring in their own coffee equipment so as not to suffer the office brew. Or perhaps he volunteered to order the office supplies and therefore got to decide for everyone else. Yep, that’s definitely one way to do it.

But like many of us, he is now operating out of a home office. Even so, he’s got better things to do than stand around pouring the perfect cup of coffee every morning. See, that’s where we differ, [Alberto]. But we do love Cafeino, your automated pour-over machine. It’s so sleek and lovely, and we’re sure it does a much better job than we do by hand — although we enjoy doing the pouring ourselves.

Cafeino is designed to mimic the movements of a trained barista’s hand, because evidently you’re supposed to pour the water in slow, deliberate swirls to evenly cover the grounds. (Our kettle has a chunky spout, so we just sort of wing it.) Cafeino does this by pumping water from an electric kettle and pouring a thin stream of it in circles with the help of two servos.

The three buttons each represent a different recipe setting, which specifies the amount of water, the hand pouring pattern, and the resting times between blooming the grounds and actually pouring the bulk of the water. These recipes are set using the accompanying web app via an ESP32, although the main brain barista is an Arduino Nano. Grab a cup and check out the demo after the break.

Got an old but modern coffee robot lying around? You could turn it into a planter with automated watering.

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Tardygrade Walker Is A Lesson In 3D Printed Design

July 23, 2021 by Danie Conradie 12 Comments

The ability to quickly create complex parts with 3D printers has created a platform to show off mechanical design skills. This is true in the case of [Dejan Ristic]’s capable little Tardygrade walking robot, which uses only two servos and a bunch of clever 3D printed parts.

The robot’s chassis is split into two subassemblies, each with a pair of feet on diagonal corners. As one pair of feet lifts the robot, the other section of the robot can rotate before coming back down, allowing the robot to turn. One servo handles the actuation of the feet, while the other rotates the body as required. An ESP32 based controller creates a web server user interface, and power comes from a lipo cell.

The interesting part of this robot is in how [Dejan] designed it for printing and assembly. All the parts can print without support, and in the correct orientation to optimize strength. There are only six screws in the assembly holding the servo and servo horns, while everything else uses snap fits or short pieces of filament. Take a look at the videos after the break to gain some appreciation of the design effort and attention to detail that went into this robot. Even the contact surfaces of the feet were carefully designed for optimum walking over flat surfaces and small obstacles.

This reminds us of [gzumwalt]’s little 3D printed creations, like the fridge crawler and mechanical edge-avoiding robot.

It’s Linux – But On An ESP32

July 21, 2021 by Jenny List 44 Comments

GNU/Linux is an open-source marvel that has over the past three decades given us an almost infinitely versatile and powerful UNIX-like operating system. But even it has its limitations, particularly at the lower end of the hardware scale where less fully-featured processors often lack the prerequisites such as a memory management unit. Thus [JuiceRV]’s feat of booting a Linux kernel on an ESP32 microcontroller seems impossible, what’s happening?

The ESP’s dual 32-bit Xtensa cores are no slouch in the processing power department, but without that MMU it’s not an obvious Linux candidate platform. The solution to this problem comes in the form of an emulated RISC-V virtual machine which provides just enough grunt for a Linux 5.0.0 kernel to boot.

By any measure this represents an impressive piece of work, but will this new-found ability to run Linux on a microcontroller take the world by storm? Of course not, unless your tastes run to the very slowest of computing experiences. It is however the essence of the hack, and for that we salute it.

It’s not the first time Linux has run on a microcontroller, in the past someone hooked up a 30 pin SIMM and an SD card to an 8-bit Atmel chip and did it in a similar way with an ARM emulator.

Via CNX Software.

Header image: Ubahnverleih, CC0.

Motorized Camera Slider Gives Your Shots Style

July 11, 2021 by Tom Nardi 1 Comment

We’ve all seen those smooth panning shots, which combined with some public domain beats, are a hallmark of the modern YouTube tech video. Recreating that style in your own productions is as easy as pointing your browser to Amazon and picking up a motorized camera slider, so long as you don’t mind parting with a few hundred bucks, anyway. But [Paweł Spychalski] had a better idea. He decided to build his own camera slider and make it an open source project so others could spin up their own versions.

His design uses many components that have become popular and affordable thanks to the desktop 3D printer explosion, such as 2020 aluminum extrusion, LM8UU linear bearings, an 8 mm lead screw, and a NEMA 17 stepper motor. In fact, if you’ve got a broken 3D printer that you don’t know what to do with, stripping it for parts would get you a long way towards completing the BOM for this project.

To control the slider, [Paweł] is using an ESP32 and TMC2209 “StepStick” driver connected to an OLED display and a few buttons. As designed, a smartphone connected to a simple web page hosted by the ESP32 is the primary method of controlling the camera, but the buttons and display on the slider itself gives you a physical backup should you need it.

If you need something a bit more advanced than a linear slider, we’ve seen some impressive DIY motion rigs that can spin the camera around the target and produce some very professional looking shots.

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Messaging On Signal Via The ESP32

July 5, 2021 by Lewin Day 15 Comments

Signal is a popular encrypted messaging app, typically used on smartphones. The cross-platform service can now be used via the ESP32, however, thanks to the work of [Dharmik] and [Tirth].

The demonstration is simple, using an ESP32 microcontroller fitted with two push buttons. When one button is pushed, it increments a counter and sends a Signal message noting the current count. The other button sends an image as a Signal message.

The project relies on a Signal bot to deliver an API key that enables the project to work. Messages are sent by making HTTP requests with this key to the CallMeBot.com server. With the API key as authentication, users can only send messages to their own number, keeping the system safe from spammers.

While the demonstration is basic, it merely serves to illustrate how the project works. The aim was to allow home automation and other Internet of Things systems to send Signal messages, and through this method, it’s now possible. The highly security conscious likely won’t want to rely on a random third party server, but for those tinkering around, it may not be such a big deal.

The Internet of Things has a long history with self-messaging projects; we featured the Twittering Toaster back in 2008! Video after the break.

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E-Ink Equipped Sourdough Starter Jar

July 3, 2021 by Danie Conradie 2 Comments

One of the unexpected side effects of our this pandemic is a sudden growth in the global population of captive colonies of Lactobacillus bacteria and yeast. Also known as sourdough starters, they are usually found in jars with curious names written on top, living off a mixture of flour and water. They require close monitoring to keep them healthy and to determine when they are ready for baking. [Noah Feehan] has been working to instrument and automate the process for the past two years, and has created a high-tech jar to keep an eye on his sourdough starter.

For a sourdough starter to stay active, it must be kept within a certain temperature range, and performance is measured by how much the level inside the jar rises. Existing open source and commercial projects monitor these two parameters and transmit data out, but [Noah] wanted to include a few more features. The height of a sourdough starter rises due to the production of CO2, so he added an SCD-30 sensor module, which includes a temperature and humidity sensor. For level monitoring, an VL6180 time-of-flight sensor is mounted over a hole on top of the jar. [Noah] wanted to be able to see recent CO2 production and height stats right on the jar, a ESP32 module with onboard E-ink display was used. To draw air over the CO2 sensor at a constant rate, a small extraction fan was also added. Power is provided by a small LiPo battery. For long term logging, the data is sent over MQTT to a server running Mycodo environmental regulation software.

There are still several software improvements [Noah] would like to make, including battery life, user interface and alerts, but everything is open-source and available on GitHub, so feel free to jump in and build your own.

ESP32 Turned Handy SWD Flasher For NRF52 Chips

July 1, 2021 by Tom Nardi 9 Comments

Got an nRF52 or nRF51 device you need to flash? Got an ESP32 laying around collecting dust? If so, then firmware hacking extraordinaire [Aaron Christophel] has the open source code you need. His new project allows the affordable WiFi-enabled microcontroller to read and write to the internal flash of Nordic nRF52 series chips via their SWD interface. As long as you’ve got some jumper wires and a web browser, you’re good to go.

In the first video below [Aaron] demonstrates the technique with the PineTime smartwatch, but the process will be more or less the same regardless of what your target device is. Just connect the CLK and DIO lines to pins GPIO 21 and GPIO 19 of the ESP32, point your web browser to its address on the local network, and you’ll be presented with a straightforward user interface for reading and writing the chip’s flash.

As demonstrated in the second video, with a few more wires and a MOSFET, the ESP32 firmware is also able to perform a power glitch exploit on the chip that will allow you to read the contents of its flash even if the APPROTECT feature has been enabled. [Aaron] isn’t taking any credit for this technique though, pointing instead to the research performed by [LimitedResults] to explain the nuts and bolts of the attack.

We’re always excited when a message from [Aaron] hits the inbox, since more often that not it means another device has received an open source firmware replacement. From his earlier work with cheap fitness trackers to his wildly successful Bluetooth environmental sensor hacking, we don’t think this guy has ever seen a stock firmware that he didn’t want to immediately send to /dev/null.

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