Author: Bryan Cockfield

1839 Articles

20 FPS On E-Paper Display Without Help

July 21, 2026 by 5 Comments

If electronic paper displays have one downside, it’s generally refresh rate. Earlier versions of the tech might only have been able to do single-digit frames per second, while modern, mid-range devices can sometimes manage 10-20 FPS — and that’s not including the frames needed to blank the display. Getting up past that double-digit barrier typically requires higher-end displays, more powerful processors or FPGAs, and more money. On the other hand, [Tony] was recently able to get 20 FPS out of an ESP32-based device without using any extra processing power.

The key to improving e-paper performance is understanding how the display actually works. The “ink” consists of microscopic charged pigment particles that physically move in response to electric fields, making the display much slower than LCD or OLED panels. Rather than fully erasing and redrawing every frame, the software takes advantage of the particles’ existing state by generating optimized driving waveforms that only move the particles needed to produce the next image. On the software side, an MPEG-like encoding is used so only changes between frames are transmitted and converted into these waveforms, reducing unnecessary data transfers and allowing much higher frame rates.

Tony’s method is able to drive 960×540 panels, like those found in the Lilygo or M5PaperS3, to 20 FPS, and these platforms are based on nothing more than the capable but limited ESP32 chip. It’s an impressive push, and worth checking out the video in the linked project page. We assume you’d need a little more to drive something like the massive e-paper display found in this home automation setup, though.

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A Feature-Rich Drum Machine

July 20, 2026 by 5 Comments

A little over a month ago, we featured a project from [Igor] who built 64 bits of DRAM from scratch using discrete components. Jokes about memory pricing aside, he did have a use case for such a small amount of memory — he is using it in a custom-built drum machine. But featuring the memory build and not the drum machine was perhaps putting the cart before the horse, so in this video, [Igor] shows off the construction of each part of his impressive 16- or 64-step sequence drum machine.

This isn’t Igor’s first drum machine, either, although his previous build was a bit more limited. It had fewer steps in the sequence and didn’t quite have the range of his newer model. The upgraded version can play more steps but also includes force-sensitive drum pads based on piezo sensors and more voices (drums) as well. Each voice is built electronically using various op-amps and passive components, and [Igor] has the schematics for each of them, as well as every other part of the drum machine, for those looking to recreate any part of this on their own. There’s a lot going on in this lengthy video as well, so for the musically inclined, it’s worth taking a look in full.

Now that our horse is in the correct position in front of the cart, it’s worth going back and looking at the memory build if you missed it when it first ran. A small amount of memory makes the machine programmable rather than just playable, and truly expands the capabilities of a machine like this in the recording studio.

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Pong-like Cabinet For Classic Dinosaur Jumper

July 19, 2026 by 2 Comments

Back when Google ran a functional search engine, there used to be all kinds of quirky, fun antics hidden in their products. From Easter eggs in certain search results, to a flight simulator hidden in Google Maps, to funny, engaging April Fools jokes, it was a lighter, less corporate time. Now, though, to recreate any of that early Google magic, we have to do it on our own, and [Paul] has come up with an arcade cabinet for the classic Google Chrome dinosaur game that does just that.

Although the Dinosaur Game is still available in modern versions of Google Chrome, it lends itself almost perfectly to an arcade cabinet. Built from 18 mm plywood, the cabinet is standard DIY arcade fare with a built-in shelf to house the electronics and a 4:3 flatscreen monitor for a display. The Raspberry Pi 3B is also just enough to run the game, but the software running on it is unique. The Pi runs an operating system called FullPageOS, which automatically loads a modified version of the Dino jumper in full-screen mode. It’s been changed to look more like an arcade game than a browser Easter egg, with features like a leaderboard and an automatic-play screensaver mode, and the build is rounded out by a cactus-shaped scratching post to accompany the cabinet.

As for gameplay, we couldn’t ask for a simpler user interface. A single button is all that’s needed for this game, and it’s surprisingly engaging. It is a bit large for a single-button game, even with its reduced-width cabinet, so if you’re looking for something smaller, you could always base it on a tabletop arcade system instead.

Using Solar Air Heating To Dry Clothes

July 17, 2026 by 47 Comments

About a month ago, [Greenhill Forge] built a few solar panels to collect energy from the sun. Unlike solar photovoltaics, which turn sunlight directly into electricity, these were designed to gather solar thermal energy with air. These types of panels can gather a tremendous amount of energy for a very low cost, and although the first video only went into the theory of their operation, his latest video actually shows us how to use that energy in a practical way.

The video starts by building a new solar panel, using upgraded materials and building methods compared to the previous versions which should improve the efficiency. There’s some data analysis of the performance, but at the end of the video [Greenhill Forge] actually hooks one of these up to a clothes dryer to explore its real-world efficacy. This process involves disconnecting the electric heater, removing one of the blower fans, and building a new flange to accept the heated air from the solar panel. A microcontroller keeps an eye on the incoming air temperature and controls a fan to try to hit the target temperature.

After an hour of drying, the test clothing was completely dry, with the only electricity used to turn the drum in the dryer. This is more than an order of magnitude of reduction in the power needed to dry clothes, which is fairly impressive. [Greenhill Forge] also notes that systems like these could augment off-grid systems not only for clothes drying but for home heating, greenhouse heating, or drying out various crops and that they could reduce strain on an electrical system that otherwise relies on resistive heating methods. There are many ways of building these panels, so be sure to check out his first video for ideas. Continue reading “Using Solar Air Heating To Dry Clothes” →

Five Solar Air Heating Methods Tested

July 4, 2026 by 63 Comments

For as good as solar panels are at converting sunlight directly into usable electricity, especially for how cheap they’re becoming, they can still only gather around 20-30% of the energy that hits them. That’s fine if you have a large roof or a huge tract of land, but if you have limited space and need to do something like heat a home, there are better options available to capture more of that energy. [Greenhill Forge] has built five solar air heating panels to test this concept, and do it much more inexpensively than commercial options.

These solar heaters use sunlight to heat a fluid, in this case air, and move that heated fluid to another space. Each panel is about two square meters, insulated on all sides except the top, and configured in a way that air can flow past something that the sun has heated. The first panel, a control, does not use a glazing to help trap this heat, but the rest all have a polycarbonate window to increase the greenhouse effect of the panels. The four remaining all experiment with the way air flows around a black corrugated steel sheet to gather more of the heat, with the fifth panel using a set of black screen instead.

With the panels all set out in the sun, [Greenhill Forge] is using a set of thermocouples from a previous project to measure the efficiency of each panel. Surprisingly, he found that the panel using the layers of screen was the best at gathering energy, although he notes several times that these types of panels are extremely sensitive to changes in physical configuration, so this is not the most definitive test possible. However, at only around $100 per panel it’s quite a deal if the goal is a usable space heater that doesn’t use any fuel or grid electricity.

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Microdistillery For Microchemistry

July 3, 2026 by 21 Comments

Much like radio operators being encouraged to use the least possible amount of power to make a contact, chemists have a similar rule encouraging using the least amount of materials in experiments. Not only is this rooted in economics, but in safety as well; if something goes wrong it’s generally good if there’s not excess amounts of reactants. With modern techniques, though, it’s possible to bring experimental chemistry down to incredibly small scales, and [Marb’s lab] found that they needed a custom built still for these new, diminutive experiments.

The first step is to build the heating component of the still. This is provided with a few custom aluminum parts for the base and a pair of heaters originally meant for 3D printers, with the assembled unit wrapped in insulation. The heater accomodates a 25 mL round-bottom flask. Temperature control of the heating mantle is provided by a controller mounted to a DIN rail which receives power from a 24V power supply, and an additional temperature probe is added to measure the temperature of the distillate. A test run with water shows the small still quickly and efficiently evaporating the water up to a condenser.

Although building a still doesn’t have to be technically difficult, building something this small that’s effective and safe is a bit more challenging than a backyard moonshining operation. Scaling chemical reactions down can often be a challenge but is possible with the right mindset and equipment. We’ve seen miniaturization of many things that we might not have expected including hydrogen production, aluminum smelting, and even the construction of a microscope.

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Modern E-Ink Dashboards, Kindle And Otherwise

July 3, 2026 by 13 Comments

People have been attempting to turn Kindles into more than e-readers since the first devices came out nearly two decades ago. The e-ink displays are low-power and great for displaying information that doesn’t refresh too often, and with Amazon continuing their trend of bricking their older devices there will be more of these devices available. [Hemant] built a weather dashboard with one of his, but since then had requests for other types of e-reader dashboards and has a guide for making more general-purpose use of an old Kindle.

The first approaches outlined here involve the installation of a dashboard client on the Kindle and pointing it at a server that hosts a PNG image of whatever information needs to be displayed. The client simply displays that image and refreshes it at predetermined intervals. There are a number of options for creating that server as well, including using Home Assistant for those who already have a home automation system deployed. The benefit of using Home Assistant is that it’s much more straightforward to gather data for the dashboards from sensors and other peripherals that are already installed.

Installing a client like this might seem straightforward, and it can be, provided that the Kindle involved is jailbroken or capable of being jailbroken. An Amazon update recently broke many modern devices’ ability to execute the jailbreak, so not every Kindle can do this anymore. But [Hemant] goes into detail about this and also outlines some methods for using generic e-ink displays instead, and also dives into the hardware and software behind building a server to host the dashboard images for those without Home Assistant already running. It’s a great overview for those who have always wanted something like this but never knew where to start.