Heat Pump Control That Works

September 4, 2023 by 33 Comments

Heat pumps are taking the world by storm, and for good reason. Not only are they many times more efficient than electric heaters, but they can also be used to provide cooling in the summer. Efficiency aside, though, they’re not perfectly designed devices, largely with respect to their climate control abilities especially for split-unit setups. Many of them don’t have remotely located thermostats to monitor temperature in an area, and rely on crude infrared remote controls as the only user interface. Looking to make some improvements to this setup, [Danilo] built a setup more reminiscent of a central HVAC system to control his.

Based on an ESP32 from Adafruit with an integrated TFT display, the device is placed away from the heat pump to more accurately measure room temperature. A humidity sensor is also included, as well as an ambient light sensor to automatically reduce the brightness of the display at night. A large wheel makes it quick and easy to adjust the temperature settings up or down. Armed with an infrared emitter, the device is capable of sending commands to the heat pump to more accurately control the climate of the room than the built-in controls are able to do. It’s also capable of logging data and integrating with various home automation systems.

While the device is optimized for the Mitsubishi heat pumps that [Danilo] has, only a few lines of code need to be changed to get this to work with other brands. This is a welcome improvement for those frustrated with the inaccurate climate controls of their heat pumps, and since it integrates seamlessly into home automation systems could also function in tandem with other backup heat sources, used in cold climates when it’s too cold outside to efficiently run the heat pump. And, if you don’t have a heat pump yet, you can always try and build your own.

Developing A 4,500 RPM Twin-Cylinder Air Engine

September 4, 2023 by 20 Comments

Compressed air isn’t really a practical form of energy storage for headline uses like transport or heating, but it’s a fun thing to tinker with at the small scale. [Tom Stanton] is plenty experienced in that area, having built a series of compressed air engines over the years. His latest effort is capable of running at up to 4,500 RPM, and delivering a full 0.05 horsepower.

Two-cylinder power!

[Tom’s] ultimate goal is to put his new tiny air engine on a small model aircraft. To enable consistent performance, his engine needs a regulator, but off-the-shelf models for industrial use were too hefty for his use. Thus, he set about equipping his engine with a lightweight regulator of his own 3D-printed design.

His latest ball-valve air engine was then designed to run on this lower regulated pressure of approximately 30 psi. It initially proved less efficient than his previous designs, but some engineering analysis revealed the problem. [Tom] does a great job of stepping through his process of understanding how these engines perform, and how he uses these findings to guide his design choices going forward.

It’s also great to see a YouTuber not just building fun things, but taking measurements and doing some real engineering. [Tom’s] air engines keep getting better, and we can’t wait to see where he takes his designs next.

Continue reading “Developing A 4,500 RPM Twin-Cylinder Air Engine” →

The ‘Scope Of This Kickstarter? Ten Years.

September 4, 2023 by 18 Comments

It may have taken ten years to come through on this particular Kickstarter, but a promise is a promise. In late August 2023, backers who had since likely forgotten all about the project started receiving their oscilloscope watches from creator [Gabriel Anzziani]. Whatever the reason(s) for the delay, the watch looks great, and is miles ahead of the prototype pictures.

As you may have guessed, it functions as both a watch and an oscilloscope. The watch has 12- and 24-hour modes as well as an alarm and calendar, and the ‘scope has all the features of the Xprotolab dev board, which [Gabriel] also created: ‘scope, waveform generator, logic analyzer, protocol sniffer, and frequency counter.

Internally, it has an 8-bit Xmega microcontroller which features an internal PDI, and the display is a 1.28″ E ink display. When we covered this ten years ago, the screen was the type of Sharp LCD featured in the Pebble watch. [Gabriel]’s ‘scope watch features eight buttons around the edge which are user-programmable. One of [Gabriel]’s goals was for people to make their own apps.

Of course, the Kickstarter rewards are no longer available, but if you want to build your own small, digital ‘scope, check out this DIY STM32 project.

Image via the Company Formerly Known As Twitter

Minimalist LED Lamp Is Circular Beauty Incarnate

September 4, 2023 by 8 Comments

Lamps used to be things built to provide light with specific purpose, whether as reading lamps, desk lamps, or bedside table lamps. Now we just build them for the vibes, as with this minimalist LED lamp from [andrei.erdei].

The build uses a 3D-printed frame printed in opaque grey, with a diffuser element printed in a more translucent white. This is key to allowing the LED to nicely glow through the lamp without ugly distracting hotspots spoiling the effect. The lamp mounts 36 WS2812B LEDs in strip form. These are controlled from an Arduino Nano running the FastLED library for lightweight and easy control of the addressable LEDs. Smooth rainbow animations are made easy by the use of the HSV color space, which is more suitable for this job than the RGB color space you may otherwise be more familiar with.

[andrei.erdei] does a great job of explaining the build, including the assembly, electronics, and code aspects. The latter could serve as a particularly good resource if you’re just starting out on your own builds in the blinky, glowable space. Video after the break.

Continue reading “Minimalist LED Lamp Is Circular Beauty Incarnate” →

See Some Of The Stranger VR Ideas From SIGGRAPH

September 4, 2023 by 15 Comments

[Devin Coldewey] shared his experiences with some of the more unusual VR concepts on display at SIGGRAPH 2023. Some of these ideas are pretty interesting in their own right, and even if they aren’t going to actually become commercial products they give some insight into the kinds of problems that are being worked on. Read on to see if anything sparks ideas of your own.

In the area of haptics and physical feedback, Sony shared research prototypes that look like short batons in which are hidden movable weights. These weights can shift up or down on demand, altering their center of gravity. [Devin] states that these units had a mild effect on their own, but when combined with VR visuals the result was impressive. There’s a video demonstration of how they work. Continue reading “See Some Of The Stranger VR Ideas From SIGGRAPH” →

Fiery Torch Build Is Remarkably Stylish

September 4, 2023 by 7 Comments

Hollywood movies, RPGs, and Dungeons and Dragons campaigns are all full of flaming torches. They’re a typical source of light in scenarios where electrical solutions simply aren’t available. [Wesley Treat] decided to build a rather attractive ceremonial torch of his own design, showing off his impressive crafting skills in the process.

The torch ignited a pretty rad sculpture.

The build starts with a foam simulacra that helps [Wesley] rough out the general shape of the torch. It’s a little shorter and stubbier than an Olympic torch might be, for reference. The main body of the torch is then hewn out of stout wooden blocks with the aid of a bandsaw with a nifty angle-adjustable cutting bed. A torch was then used to heat and bend steel strip  to make an attractive and heat-resistant flame shroud to sit on top. A wad of fuel-soaked material installed inside the shroud serves as the actual flaming compoment.

[Wesley] built the torch for the Maker Burn at Maker Camp in upstate New York. It did a plenty good job of helping burn down the giant scrap wood jackalope  sculpture built for the event. We do love the fire and the flames around these parts. Video after the break.

Continue reading “Fiery Torch Build Is Remarkably Stylish” →

Modding A Nerf Blaster The Old Fashioned Way

September 3, 2023 by 3 Comments

The Pistol Splat was a very weak blaster built for children, designed to shoot toy-grade paintball-like ammunition. [Matt Yuan] recognised the potential of the single-shot design, though, and repurposed it as a powerful Nerf blaster.

The blaster is a simple spring-plunger design. Upon pulling the trigger, the spring drives the piston forward, shooting the ammunition out the barrel. As stock, the Pistol Splat featured an incredibly strong spring and an unrestricted barrel, giving it plenty of performance capability. With some finagling, it’s capable of shooting a Nerf dart at 100 feet per second in stock form.

[Matt] improved the blaster by removing its dry-fire protection spring, which consists of a second spring to resist the plunger’s motion. Modification also involved fitting a barrel sized to properly seal on the darts. These two mods boosted the dart velocity to 110 feet per second. Adding a spacer to ensure the spring fully drove the piston forward for its full travel further boosted the dart velocity to a mighty 145 feet per second.

It bears noting that serious Nerf blasters like these demand eye protection. Video after the break.

Continue reading “Modding A Nerf Blaster The Old Fashioned Way” →