Easily Program RP2040 Boards With Your Android Device

October 11, 2024 by 8 Comments

You could write your microcontroller code on your desktop PC, or you could do it on your laptop on the go. Or, if you want to get really portable about things, you could write your embedded code on your phone. Enter DroidScript.

Basically, DroidScript is a JavaScript and Python IDE for Android phones and tablets. Simple enough. You can use it to write apps for your phone or tablet. But its party piece? You can now also use it to program for embedded devices—namely, a range of those based on the RP2040 microcontroller. For example, the Adafruit QT-Py RP2040, the Pimoroni TinyFX, or the Pimoroni Yukon. They run MicroPython and CircuitPython, and you can program them from DroidScript. Easy.

A decade ago, this would have been a royal pain in the butt. But today? It’s easy, because the smartphones and devboards both use USB-C connectors. All you need is a regular USB-C cable and you can hook straight up to the board and burn your code.

You can get the app on the Google Play Store if you’re so inclined. We’ve seen some other neat smartphone programming projects over the years, too. Meanwhile, if you’ve found any other nifty ways to get your code on to a dev board, don’t hesitate to let us know!

Tiny Drones Do Distributed Mapping

October 11, 2024 by 12 Comments

Sending teams of tiny drones to explore areas and structures is a staple in sci-fi and research, but the weight and size of sensors and the required processing power have long been a limiting factor. In the video below, a research team from [ETH Zurich] breaks through these limits, demonstrating indoor mapping with a swarm of tiny drones without dependence on any external systems.

The drone is the modular Crazyflie platform, which uses stackable PCBs (decks) to expand capabilities. The team added a Flow deck for altitude control and motion tracking, and a Loco positioning deck with a UWB module determining relative distances between drones. On top of this, the team added two custom decks. The first mounts four VL53L5CX 8×8 pixel TOF sensors for omnidirectional LIDAR scanning. The final deck does handles all the required processing with a GAP9 System-on-Chip, which features 10 RISC-V cores running on just 200 mW of power.

Of course the special sauce of this project lies in the software. The team developed a lightweight collaborative Simultaneous Localization And Mapping (SLAM) algorithm which can be distributed across all the drones in the swarm. It combines LIDAR scan data and the estimated position of the drone during the scan, and then overlays the data for the scans for each location across different drones, compensating for errors in the odometry data. The team also implemented inter-drone collision avoidance, packet collision avoidance and optimizing drones’ paths. The code is supposed to be available on GitHub, but the link was broken at the time of writing.

The Crazyflie platform has been around for more than a decade now, and we’ve seen it used in several research projects, especially related to autonomous navigation. Continue reading “Tiny Drones Do Distributed Mapping” →

Symbolic Nixie Tubes Become Useful For Artistic Purposes

October 10, 2024 by 2 Comments

When it comes to Nixie tubes, the most common usage these days seems to be in clocks. That has people hunting for the numerical version of the tubes, which are usually paired with a couple of LEDs to make the colon in the middle of the clock. However, other Nixie tubes exist, like the IN-7, which has a whole bunch of neat symbols on it instead. [Joshua] decided to take these plentiful yet less-popular tubes and whip them up into a little art piece. 

The IN-7 is a tube normally paired with the numerical IN-4 tube in instrumentation, where it displays unit symbols relevant to the number being displayed. It can display omega, +, M, pi, m, A, -, V, K, and ~.

[Joshua]’s build is simple enough. It spells the word “MAKE” in Nixie tubes as a neat sign for a makerspace. It uses “M” for Mega, “A” for Amps, “K” for Kilo for the first three letters. The fourth letter, “e”, is achieved by turning the tube 90 degrees, so the “m” for milli approximates that character. Two rows spelling “MAKE” (or “MAKe”) are assembled, powered via a small circuit which [Joshua] assembled on a custom-etched board using the toner transfer process. The electronics are all wrapped up in a neat laser-cut acrylic enclosure which was designed in Inkscape.

It’s a neat little project which makes good use of a Nixie tube that is, by and large, unloved. It also recalls us of a misspent youth, writing silly words on scientific calculators using only the available Greek characters. Meanwhile, if you’re working on your own Nixie builds, we’ve featured some neat drivers that you might just find valuable.

Continue reading “Symbolic Nixie Tubes Become Useful For Artistic Purposes” →

A vaguely boat-shaped vehicle with three wheels and a mast. It sits in a barren-looking plain with short mountains in the distance

Sailing The High Steppes

October 10, 2024 by 29 Comments

Sails typically bring to mind the high seas, but wind power has been used to move craft on land as well. Honoring this rich tradition, [Falcon Riley] and [Amber Word] decided to sail across Mongolia in “Moby the Land Sailing vessel.”

Built in a mere three days from $200 in materials they were able to scrounge up the week before, the cart served as their home for the 300 km (~186 mi) journey across the Mongolian countryside. Unsurprisingly, bodging together a sailing vessel in three days to traverse uneven terrain led to a failed weld to the front tire, but a friendly local lent a hand to get them back on the road.

Built mostly out of plywood, the fully-laden cart tipped the scales at 225 kg (500 lbs) and could still be towed by hand. Under sail, however, they managed 70 km in one particularly windy day. They covered the distance in 46 days, which isn’t the fastest way to travel by any means, but not bad given the quick build time for this house on wheels. We suspect that a more lightweight and aerodynamic build could yield some impressive results. Maybe it’s time for a new class at Bonneville?

If you want to learn to sail in your own landlocked region, maybe learn a bit first? Instead you might want to build an autonomous sailing cart or take a gander at sailing out of this world?

[Thanks to Amber for stopping by to suggest some corrections!]

A Power Supply With Ultra High Resolution Current Measurement Built In

October 10, 2024 by 11 Comments

Need to do some real fine power consumption measurements? [Gero Müller] was in that exact situation, and wasn’t happy with the expensive off-the-shelf tools for doing the job. Thus, he built his own. Meet nanoTracer.

nanoTracer measures small current draws in very high resolution.

The concept of the device is simple. It’s a power supply that measures current on a nanoampere scale, and on microsecond intervals. It can deliver from 0 to 5.125 volts in 256 steps, and up to 100 mA of current. It has a sampling bandwidth of 1 MHz, at 2 million samples per second, with effective dynamic range from 100 mA all the way down to 100 nA. For capturing microscopic changes in current draw, that’s invaluable. The device also features a UART for talking to an attached project directly, and additional pins for taking further ADC measurements where needed.

Right now, it’s at an early prototype stage, and [Gero] tells us the software is “very basic” right now. Still, it’s easy to see how this device would be very useful to anyone working to optimize power consumption on low-power projects. One wonders if there are some applications in power-based side-channel attacks, too.

We’re hoping to learn more about nanoTracer from [Gero] soon—how it was built, how it works, and what it’s really like to use. Perhaps one day down the line, the design might even become available for others that could use such a nifty tool. There’s no mucking about when you get down to nanoamps, after all. If you’ve cooked up something similar in your own lab, don’t hesitate to let us know!

Building A Sound Camera For Under $400

October 10, 2024 by 22 Comments

[Benn Jordan] had an idea. He’d heard of motion amplification technology, where cameras are used to capture tiny vibrations in machinery and then visually amplify it for engineering analysis. This is typically the preserve of high-end industrial equipment, but [Benn] wondered if it really had to be this way. Armed with a modern 4K smartphone camera and the right analysis techniques, could he visually capture sound?

The video first explores commercially available “acoustic cameras” which are primarily sold business-to-business at incredibly high prices. However, [Benn] suspected he could build something similar on the cheap. He started out with a 16-channel microphone that streams over USB for just $275, sourced from MiniDSP, and paired it  with a Raspberry Pi 5 running the acoular framework for acoustic beamforming. Acoular analyses multichannel audio and visualizes them so you can locate sound sources. He added a 1080p camera, and soon enough, was able to overlay sound location data over the video stream. He was able to locate a hawk in a tree using this technique, which was pretty cool, and the total rig came in somewhere under $400.

The rest of the video covers other sound-camera techniques—vibration detection, the aforementioned motion amplification, and some neat biometric techniques. It turns out your webcam can probably detect your heart rate, for example.

It’s a great video that illuminates just what you can achieve with modern sound and video capture. Think SIGGRAPH-level stuff, but in a form you can digest over your lunchbreak. Video after the break.

Continue reading “Building A Sound Camera For Under $400” →

Supercon 2023: Receiving Microwave Signals From Deep-Space Probes

October 10, 2024 by 5 Comments

Here’s the thing about radio signals. There is wild and interesting stuff just getting beamed around all over the place. Phrased another way, there are beautiful signals everywhere for those with ears to listen. We go about our lives oblivious to most of them, but some dedicate their time to teasing out and capturing these transmissions.

David Prutchi is one such person. He’s a ham radio enthusiast that dabbles in receiving microwave signals sent from probes in deep space. What’s even better is that he came down to Supercon 2023 to tell us all about how it’s done!

Continue reading “Supercon 2023: Receiving Microwave Signals From Deep-Space Probes” →