small

29 Articles

How Small Can The ESP32 Get?

September 7, 2023 by 22 Comments

At its core, the ESP32 chip is not much more than an integrated circuit, a huge mass of transistors sealed inside an epoxy resin package with some leads. Of course, most of us won’t buy discrete ESP32 chips with no support circuitry since it’s typically easier and often not that much more expensive to get them paired with development boards of some type for easy access to things like USB and GPIO. But these tiny chips need little in the way of support to get up and running as [Paul] demonstrates with this tiny ESP32 board.

The project started as a challenge for [Paul] to build the smallest ESP32 that would still function. That means carving away nearly everything normally found accompanying one of these chips. There is no charging circuitry, only one of the GPIO pins is accessible, and it even foregoes the WiFi antennas which eliminates the major reason most people would reach for this chip in the first place. But at this form factor even without wireless capabilities it still blows other chips of this stature, like the ATtiny series, out of the water.

Even though [Paul] built it as a challenge, it goes a long way to demonstrate what’s really needed to get one of these chips up and running properly. And plenty of projects don’t need a ton of I/O or Wi-Fi either, so presuming these individual chips can be found cheaply and boards produced for various projects its an excellent way to minimize size and perhaps even power requirements. You can make these boards even smaller than a USB-A connector if you want to take this process even further, too.

Continue reading “How Small Can The ESP32 Get?” →

MeArm 3.0: The Pocket-Sized Robot Arm

June 26, 2023 by 14 Comments

We all might dream of having an industrial robot arm at our disposal, complete with working controller that doesn’t need constant maintenance and replacement parts, and which is able to help us with other projects with only a minimum of coding or instruction. That’s a pipe dream for most of us, as without a large space, sufficient funding, or unlimited amounts of troubleshooting time we’ll almost always have to look for something smaller and simpler. Perhaps something even as small as this pocket-sized robotic arm.

This isn’t actually the first time we’ve seen the MeArm; the small robot has been around since 2014 and has undergone a number of revisions and upgrades. Even this revision has been out for a little while now but this latest in the series is now available with a number of improvements over the older models. The assembly time required has been reduced from two hours to about 30 minutes and the hardware has even been fully open-sourced as well which allows virtually anyone with the prerequisite tools to build this tiny robot for whatever they happen to need it for, due to its very permissive licensing.

The linked Instructable goes into every detail needed for building the robot as well as documenting all of the parts needed, although you will need access to some specialty tools to make a lot of them. We also featured a Friday Hack Chat about these robots back in 2018 that has some interesting details about these robots in it, and although this is a relatively small robot in the grand scheme of things it’s always possible to upgrade to something larger in the future.

Continue reading “MeArm 3.0: The Pocket-Sized Robot Arm” →

Pocket-Sized Thermal Imager

March 14, 2023 by 25 Comments

Just as the gold standard for multimeters and other instrumentation likely comes in a yellow package of some sort, there is a similar household name for thermal imaging. But, if they’re known for anything other than the highest quality thermal cameras, it’s excessively high price. There are other options around but if you want to make sure that the finished product has some sort of quality control you might want to consider building your own thermal imaging device like [Ruslan] has done here.

The pocket-sized thermal camera is built around a MLX90640 sensor from Melexis which can be obtained on its own, but can also be paired with an STM32F446 board with a USB connection in order to easily connect it to a computer. For that, [Ruslan] paired it with an ESP32 board with a companion screen, so that the entire package could be assembled together with a battery and still maintain its sleek shape. The data coming from the thermal imagining sensor does need some post-processing in order to display useful images, but this is well within the capabilities of the STM32 and ESP32.

With an operating time on battery of over eight hours and a weight under 100 grams, this could be just the thing for someone looking for a thermal camera who doesn’t want to give up an arm and a leg to one of the industry giants. If you’re looking for something even simpler, we’ve seen a thermal camera based on a Raspberry Pi that delivers its images over the network instead of on its own screen.

A Mega-Tiny Arduino

March 2, 2023 by 26 Comments

Integrated circuits, chipsets, memory modules, and all kinds of other transistor-based technology continues to get smaller, cheaper, and more energy efficient as time moves on. Not only are the components themselves smaller, but their supporting infrastructure is as well. Computers like the Raspberry Pi are about the size of a credit card and have computing power on the order of full-sized PCs from a few decades ago. The Arduino is no exception to this trend, either, and this new dev board called the Epi 32U4 might be the smallest ATmega platform we’ve seen so far.

As the name suggests, the board is based around the ATmega32U4 which is somewhat unique among Atmel chips in that it includes support for USB within the chip itself rather than relying on external translating circuitry. This makes it an excellent choice for any project which involves sending keyboard, mouse, or other peripheral information to a computer. This goes a few steps further with eliminating “bloat” compared to other boards, too — there’s no on-board voltage regulator, and just a single LEDs on pin 13.

One of the other features this board boasts over other small form factor boards is on-board USB-C, which is definitely a perk as more and more devices switch away from the various forms of older USB-type plugs. The project’s specifications are also available on this GitHub page for anyone that wants to produce their own. And, if you don’t have a 32U4 on hand and still want to build a keyboard project, it’s possible to get some other Arduinos to support these features but it’ll take a little more work.

Thanks to [Rasmus L] for the tip!

Comparing Solar Energy Harvesters

October 27, 2022 by 11 Comments

There doesn’t have to be much more to setting up a simple solar panel installation than connecting the panel to a battery. Of course we would at least recommend the use of a battery management system or charge controller to avoid damaging the battery, although in a pinch it’s not always strictly necessary. But these simple systems leave a lot on the table, and most people with any sizable amount of solar panels tend to use a maximum power point tracking (MPPT) system to increase the yield of the panels. For a really tiny installation like [Salvatore] has, you’ll want to take a look at a similar system known as a solar energy harvester.

[Salvatore] is planning to use an energy harvester at his small weather station, which is currently powered by an LDO regulator and a small solar cell. While this is fairly energy efficient, the energy harvesters that he is testing with this build will go far beyond what an LDO is capable of. The circuit actually has two energy harvesters built onto it which allows him to test the capabilities of both before he makes a decision for his weather station. Every amount of energy is critical when using the cell he has on hand, which easily fits in the palm of one’s hand.

The testing of this module isn’t complete yet, but he does have two working prototypes to test in future videos to see which one truly performs the best. For a project of this size, this is a great way to get around the problem of supplying a small amount of power to something remote. For a larger solar panel installation, you’ll definitely want to build an MPPT system though.

Continue reading “Comparing Solar Energy Harvesters” →

Tiny Pinball Machine Also Runs X86 Code

July 21, 2022 by 13 Comments

As arcades become more and more rare, plenty of pinball enthusiasts are moving these intricate machines to their home collections in basements, garages, and guest rooms. But if you’re not fortunate enough to live in a home that can support a space-intensive hobby like pinball machines, there are some solutions to that problem. This one, for example, fits on the palm of your hand and also happens to run some impressive software for its size.

The machine isn’t a mechanical pinball machine like its larger cousins, though. Its essentially a 3D printed case made to look like a pinball machine with two screens attached. It does have a working plunger for launching the ball and two buttons on the sides for the approximation of authenticity, but it’s actually running Pinball Fantasies — a pinball simulator designed to run on x86 hardware from the 90s. This sports an ESP32 on the inside, which has just enough computing capability to run an x86 emulator that can load these games in DOS.

The game includes haptic feedback and zips along at 60 frames per second, which really brings the pinball experience to its maximum level given the game’s minuscule size. It’s impressive for fitting a lot into a small space, both from physical and software points-of-view. For more full-sized digital pinball builds, take a look at this one which comes exceptionally close to replicating the real thing.

Continue reading “Tiny Pinball Machine Also Runs X86 Code” →

New Resin Printing Method Creates Objects In Seconds

June 1, 2022 by 20 Comments

For anyone looking to buy a 3D printer at home, the first major decision that needs to be made is whether to get a resin printer or a filament printer. Resin has the benefits of finer detail, but filament printers are typically able to produce stronger prints. Within those two main camps are various different types and sizes to choose from, but thanks to some researchers at Switzerland’s École polytechnique fédérale de Lausanne (EPFL) there’s a new type of resin printer on the horizon that can produce prints nearly instantaneously.

The method works similarly to existing resin printers by shining a specific light pattern on the resin in order to harden it. The main difference is that the resin is initially placed in a cylinder and spun at a high speed, and the light is shined on the resin at different angles with very precise intensities and timings in order to harden the resin in specific areas. This high-speed method allows the printer to produce prints in record-breaking time. The only current downside, besides the high price for the prototype printer, is that it’s currently limited to small prints.

With the ability to scale in the future and the trend of most new technologies to come down in price after they have been on the market for some amount of time, it would be groundbreaking to be able to produce prints with this type of speed if printers like these can be scalable. Especially if they end up matching the size and scale of homemade printers like this resin printer.

Thanks to [suicidal.banana] for the tip!