Tiny, Hackable Telepresence Robot For Under $100? Meet Goby

April 17, 2025 by Donald Papp 10 Comments

[Charmed Labs] are responsible for bringing numerous open-source hardware products to fruition over the years, and their latest device is an adorably small robotic camera platform called Goby, currently crowdfunding for its initial release. Goby has a few really clever design features and delivers a capable (and hackable) platform for under 100 USD.

Goby embraces its small size, delivering what its creators dub “tinypresence” — or the feeling of being there, but on a very small scale. Cardboard courses, LEGO arenas, or even tabletop gaming scenery hits different when experienced from a first-person perspective. Goby is entirely reprogrammable with nothing more than a USB cable and the Arduino IDE, while costing less than most Arduino starter kits.

Recharging happens by driving over the charger, then pivoting down so the connectors (the little blunt vampire fangs under and to each side of the camera) come into contact with the charger.

One of the physical features we really like is the tail-like articulated caster at the rear. Flexing this pivots Goby up or down (and can even flip Goby completely over), allowing one to pan and tilt the view without needing to mount the camera on a gimbal. It also comes into play for recharging; Goby simply moves over the disc-shaped charger and pivots down to make contact.

At Goby‘s heart is an ESP32-S3 and OmniVision OV2640 camera sensor streaming a live video feed (and driving controls) with WebRTC. Fitting the WebRTC stack onto an ESP32 wasn’t easy, but opens up possibilities beyond just media streaming.

Goby is set up to make launching an encrypted connection as easy as sharing a URL or scanning a QR code. The link is negotiated between bot and client with the initial help of an external server, and once a peer-to-peer connection is established, the server’s job is done and it is out of the picture. [Charmed Labs]’s code for this functionality — named BitBang — is in beta and destined for an open release as well. While BitBang is being used here to make it effortless to access Goby remotely, it’s more broadly intended to make web access for any ESP32-based device easier to implement.

As far as tiny remote camera platforms go, it might not be as small as rebuilding a Hot Wheels car into a micro RC platform, but it’s definitely more accessible and probably cheaper, to boot. Check it out at the Kickstarter (see the first link in this post) and watch it in action in the video, embedded just below the page break.

Continue reading “Tiny, Hackable Telepresence Robot For Under $100? Meet Goby“ →

A photograph with labels showing the parts of a DIY scanning spectrometer.

DIY Scanning Spectrometer Is A Bright Idea

April 14, 2025 by Tyler August 7 Comments

Spectroscopy seems simple: split a beam of light into its constituent wavelengths with a prism or diffraction grating, and measure the intensity of each wavelength. The devil is in the details, though, and what looks simple is often much harder to pull of in practice. You’ll find lots of details in [Gary Boyd]’s write-up of his optical scanning spectrometer project, but no devils.

Schematic diagram of [Gary Boyd]'s spectrometer, showing optical elements and rays of light as well as major physical elements like the motor and linear stage. — Schematic diagram of [Gary Boyd]’s Czerny-Turner type scanning spectrometer.

A scanning spectrometer is opposed to the more usual camera-type spectrometer we see on these pages in that it uses a single-pixel sensor that sweeps across the spectrum, rather than spreading the spectrum across an imaging sensor.

Specifically, [Gary] has implemented a Czerny-Turner type spectrometer, which is a two-mirror design. The first concave mirror collimates the light coming into the spectrometer from its entrance slit, focusing it on a reflective diffraction grating. The second concave mirror focuses the various rays of light split by the diffraction grating onto the detector.

In this case [Gary] uses a cheap VEML 7700 ambient light sensor mounted to a small linear stage from amazon to achieve a very respectable 1 nm resolution in the range from 360 nm to 980 nm. That’s better than the human eye, so nothing to sneeze at — but [Gary] includes some ideas in his blog post to extend that even further. The whole device is controlled via an Arduino Uno that streams data to [Gary]’s PC.

[Gary] documents everything very well, from his optical mounts to the Arduino code used to drive the stepper motor and take measurements from the VEML 7700 sensor. The LED and laser “turrets” used in calibration are great designs as well. He also shares the spectra this device is capable of capturing– everything from the blackbody of a tungsten lamp used in calibration, to a cuvette of tea, to the sun itself as you can see here. If you have a couple minutes, [Gary]’s full writeup is absolutely worth a read.

This isn’t the first spectrometer we’ve highlighted– you might say we’ve shown a whole spectrum of them.

Tracking The ISS Made Easy

April 7, 2025 by Elliot Williams 3 Comments

If you made something blink, and now it’s time for you to make something move, something like a point-to-a-satellite tracker is a great idea. [Farid Rener] made this moving arrow that always points at the ISS, and documented it nicely to boot.

And there’s a little bit of everything here, from orbital mechanics and fetching the two-line elements (TLE) from the web, to writing the code to translate that into the tabletop machine’s coordinate system. It looks like [Farid] hadn’t done much 3D CAD before, so he got a chance to stretch those muscles too. Finally, it served as an introduction to resource-constrained programming: “This was the first time I’ve had to think about the size of a compiled binary – the most frustrating part was figuring out that using a C++ stringstream was adding too much code to my binary.”

[Farid] is learning a lot here, and you might too. For instance, using pencil lead (graphite) as a lubricant on sliding 3D-printed parts is new to us, but makes sense. We’ll have to try that out.

And while this is a simple desktop tracker, with a lot more mechanical design, the same basics could be put to real use for pointing a receiver dish. Of course, who says you need fancy motors and computers to point a satellite dish anyway? If you work on your arm muscles a bit, you could become the satellite pointer.

Automatically Crack Safes With This Autodialer

March 30, 2025 by Bryan Cockfield 13 Comments

When attempting to secure something, whether it’s a computer, sensitive data, or valuables, there’s always going to be a way to break that security. It might be impossibly hard, like taking centuries to brute-force an encryption algorithm, but it’s weakness is still there. And, like the future might make certain encryption obsolete, modern electronics has made security of the past somewhat obsolete as well. [Startup Chuck] has been using tools the creators of safes from the late 1800s could probably not have imagined.

The tool that [Startup Chuck] has come up with is known as an autodialer in the safe-cracking world, and as its name suggests it automates the process of opening the safe by trying as many combinations as possible. The autodialer attaches to the safe with three magnetic feet and couples to the dial through a chuck attached to a magnetic clutch, which allows the autodialer to disengage as soon as the correct combination is found. It’s driven with a stepper motor which can test out combinations so fast that [Startup Chuck] needed to take 240 fps video and slow it down to make sure that the mechanism was behaving properly.

The autodialer itself can’t actually open the safe, though. The last step of the process is taken care of by a bungie cord, attached to the safe handle to pre-tension it enough so that when the correct combination is finally entered the safe pops open automatically. For anyone looking to duplicate the project, [Startup Chuck] has added the program code to a GitHub page. If you’re looking at a more modern safe, though, there are of course ways to crack their security systems as well.

Continue reading “Automatically Crack Safes With This Autodialer” →

Laser Harp Sets The Tone

March 20, 2025 by Bryan Cockfield 16 Comments

In many ways, living here in the future is quite exiting. We have access to the world’s information instantaneously and can get plenty of exciting tools and hardware delivered to our homes in ways that people in the past with only a Sears catalog could only dream of. Lasers are of course among the exciting hardware available, which can be purchased with extremely high power levels. Provided the proper safety precautions are taken, that can lead to some interesting builds like this laser harp which uses a 3W laser for its strings.

[Cybercraftics]’ musical instrument is using a single laser to generate seven harp strings, using a fast stepper motor to rotate a mirror to precise locations, generating the effect via persistence of vision. Although he originally planned to use one Arduino for this project, the precise timing needed to keep the strings in the right place was getting corrupted by adding MIDI and the other musical parts to the project, so he split those out to a second Arduino.

Although his first prototype worked, he did have to experiment with the sensors used to detect his hand position on the instrument quite a bit before getting good results. This is where the higher power laser came into play, as the lower-powered ones weren’t quite bright enough. He also uses a pair of white gloves which help illuminate a blocked laser. With most of the issues ironed out, [Cybercraftics] notes that there’s room for improvement but still has a working instrument that seems like a blast to play. If you’re still stuck in the past without easy access to lasers, though, it’s worth noting that there are plenty of other ways to build futuristic instruments as well.

Continue reading “Laser Harp Sets The Tone” →

Taming The Wobble: An Arduino Self-Balancing Bot

March 9, 2025 by Heidi Ulrich 12 Comments

Getting a robot to stand on two wheels without tipping over involves a challenging dance with the laws of physics. Self-balancing robots are a great way to get into control systems, sensor fusion, and embedded programming. This build by [mircemk] shows how to make one with just a few common components, an Arduino, and a bit of patience fine-tuning the PID controller.

At the heart of the bot is the MPU6050 – a combo accelerometer/gyroscope sensor that keeps track of tilt and movement. An Arduino Uno takes this data, runs it through a PID loop, and commands an L298N motor driver to adjust the speed and direction of two DC motors. The power comes from two Li-ion batteries feeding everything with enough juice to keep it upright. The rest of the magic lies in the tuning.

PID (Proportional-Integral-Derivative) control is what makes the robot stay balanced. Kp (proportional gain) determines how aggressively the motors respond to tilting. Kd (derivative gain) dampens oscillations, and Ki (integral gain) helps correct slow drifts. Set them wrong, and your bot either wobbles like a confused penguin or falls flat on its face. A good trick is to start with only Kp, then slowly add Kd and Ki until it stabilizes. Then don’t forget to calibrate your MPU6050; each sensor has unique offsets that need to be compensated in the code.

Once dialed in, the result is a robot that looks like it defies gravity. Whether you’re hacking it for fun, turning it into a segway-like ride, or using it as a learning tool, a balancing bot is a great way to sharpen your control system skills. For more inspiration, check out this earlier attempt from 2022, or these self-balancing robots (one with a little work) from a year before that. You can read up on [mircemk]’s project details here.

Physical Computing Used To Be A Thing

March 8, 2025 by Elliot Williams 69 Comments

In the early 2000s, the idea that you could write programs on microcontrollers that did things in the physical world, like run motors or light up LEDs, was kind of new. At the time, most people thought of coding as stuff that stayed on the screen, or in cyberspace. This idea of writing code for physical gadgets was uncommon enough that it had a buzzword of its own: “physical computing”.

You never hear much about “physical computing” these days, but that’s not because the concept went away. Rather, it’s probably because it’s almost become the norm. I realized this as Tom Nardi and I were talking on the podcast about a number of apparently different trends that all point in the same direction.

We started off talking about the early days of the Arduino revolution. Sure, folks have been building hobby projects with microcontrollers built in before Arduino, but the combination of a standardized board, a wide-ranging software library, and abundant examples to learn from brought embedded programming to a much wider audience. And particularly, it brought this to an audience of beginners who were not only blinking an LED for the first time, but maybe even taking their first steps into coding. For many, the Arduino hello world was their coding hello world as well. These folks are “physical computing” natives.

Now, it’s to the point that when Arya goes to visit FOSDEM, an open-source software convention, there is hardware everywhere. Why? Because many successful software projects support open hardware, and many others run on it. People port their favorite programming languages to microcontroller platforms, and as they become more powerful, the lines between the “big” computers and the “micro” ones starts to blur.

And I think this is awesome. For one, it’s somehow more rewarding, when you’re just starting to learn to code, to see the letters you type cause something in the physical world to happen, even if it’s just blinking an LED. At the same time, everything has a microcontroller in it these days, and hacking on these devices is also another flavor of physical computing – there’s code in everything that you might think of as hardware. And with open licenses, everything being under version control, and more openness in open hardware than we’ve ever seen before, the open-source hardware world reflects the open-source software ethos.

Are we getting past the point where the hardware / software distinction is even worth making? And was “physical computing” just the buzzword for the final stages of blurring out those lines?