Onkyo Receiver Saved With An ESP32
?w=800" alt=""/>[Bill Dudley] had a problem. He had an Onkyo AV receiver that did a great job… until it didn’t. A DSP inside failed. When that happened, the main microprocessor running https://hackaday.com/2025/04/24/onkyo-receiver-saved-with-an-esp32/
https://hackaday.com/2025/04/24/onkyo-receiver-saved-with-an-esp32/
DolphinGemma Seeks to Speak to Dolphins
?w=800" alt="A black and blue swirl background with the logo of a blue dolphin over the word DolphinGemma with dolphin in white and Gemma in blue"/>Most people have wished for the ability to talk to other animals at some point, until they realized their cat would mostly insult them and ask for better service, but https://hackaday.com/2025/04/24/dolphingemma-seeks-to-speak-to-dolphins/
https://hackaday.com/2025/04/24/dolphingemma-seeks-to-speak-to-dolphins/
A Bicycle is Abandonware Now? Clever Hack Rescues Dead Light
?w=800" alt=""/>A bicycle is perhaps one of the most repairable pieces of equipment one can own — no matter what’s wrong with it, and wherever you are on the planet, you’ll https://hackaday.com/2025/04/24/a-bicycle-is-abandonware-now-clever-hack-rescues-dead-light/
https://hackaday.com/2025/04/24/a-bicycle-is-abandonware-now-clever-hack-rescues-dead-light/
Haptic Soft Buttons Speak(er) to Your Sense of Touch
?w=800" alt=""/>There’s just something about a satisfying “click” that our world of touchscreens misses out on; the only thing that might be better than a good solid “click” when you hit https://hackaday.com/2025/04/24/haptic-soft-buttons-speaker-to-your-sense-of-touch/
https://hackaday.com/2025/04/24/haptic-soft-buttons-speaker-to-your-sense-of-touch/
The Mohmmeter: A Steampunk Multimeter
[Agatha] sent us this stunning multimeter she built as a gift for her mom. Dubbed the Mohmmeter — a playful nod to its ohmmeter function and her mom — this https://hackaday.com/2025/04/24/the-mohmmeter-a-steampunk-multimeter/
https://hackaday.com/2025/04/24/the-mohmmeter-a-steampunk-multimeter/
C64 Assembly in Parts
?w=800" alt=""/>[Michal Sapka] wanted to learn a new skill, so he decided on the Commodore 64 assembly language. We didn’t say he wanted to learn a new skill that might land https://hackaday.com/2025/04/23/c64-assembly-in-parts/
Improved and Open Source: Non-Planar Infill for FDM
?w=800" alt="Non-planar 3d-print on bed"/>Strenghtening FDM prints has been discussed in detail over the last years. Solutions and results vary as each one’s desires differ. Now [TenTech] shares his latest improvements on his post-processing https://hackaday.com/2025/04/23/improved-and-open-source-non-planar-infill-for-fdm/
https://hackaday.com/2025/04/23/improved-and-open-source-non-planar-infill-for-fdm/
Abusing DuckDB-WASM To Create Doom In SQL
?w=800" alt=""/>These days you can run Doom anywhere on just about anything, with things like porting Doom to JavaScript these days about as interesting as writing Snake in BASIC on one’s https://hackaday.com/2025/04/23/abusing-duckdb-wasm-to-create-doom-in-sql/
https://hackaday.com/2025/04/23/abusing-duckdb-wasm-to-create-doom-in-sql/
The Evertop: a Low-Power, Off-Grid Solar Gem
?w=800" alt="Black and white photo of Evertop computer on desk"/>When was the last time you saw a computer actually outlast your weekend trip – and then some? Enter the Evertop, a portable IBM XT emulator powered by an ESP32 https://hackaday.com/2025/04/23/the-evertop-a-low-power-off-grid-solar-gem/
https://hackaday.com/2025/04/23/the-evertop-a-low-power-off-grid-solar-gem/
Open Source Commercial Synthesisers You Will Love
?w=800" alt=""/>Drumboy and Synthgirl from Randomwaves are a a pair of compact electronic instruments, a drum machine and a synthesiser. They are commercial products which were launched on Kickstarter, and if https://hackaday.com/2025/04/23/open-source-commercial-synthesisers-you-will-love/
https://hackaday.com/2025/04/23/open-source-commercial-synthesisers-you-will-love/
To See Within: Detecting X-Rays
?w=800" alt=""/>It’s amazing how quickly medical science made radiography one of its main diagnostic tools. Medicine had barely emerged from its Dark Age of bloodletting and the four humours when X-rays https://hackaday.com/2025/04/23/to-see-within-detecting-x-rays/
https://hackaday.com/2025/04/23/to-see-within-detecting-x-rays/
Unsolved Questions in Astronomy? Try Dark Matter!
?w=800" alt="A false colour image of the region of sky containing the CMZ."/>Sometimes in fantasy fiction, you don’t want to explain something that seems inexplicable, so you throw your hands up and say, “A wizard did it.” Sometimes in astronomy, instead of https://hackaday.com/2025/04/23/unsolved-questions-in-astronomy-try-dark-matter/
https://hackaday.com/2025/04/23/unsolved-questions-in-astronomy-try-dark-matter/
A Scratch-Built Commodore 64, Turing Style
?w=800" alt=""/>Building a Commodore 64 is among the easier projects for retrocomputing fans to tackle. That’s because the C64’s core chipset does most of the heavy lifting; source those and you’re https://hackaday.com/2025/04/23/a-scratch-built-commodore-64-turing-style/
https://hackaday.com/2025/04/23/a-scratch-built-commodore-64-turing-style/
Virtual Nodes, Real Waves: a Colpitts Walkthrough
?w=800" alt=""/>If you’ve ever fumbled through circuit simulation and ended up with a flatline instead of a sine wave, this video from [saisri] might just be the fix. In this walkthrough https://hackaday.com/2025/04/22/virtual-nodes-real-waves-a-colpitts-walkthrough/
https://hackaday.com/2025/04/22/virtual-nodes-real-waves-a-colpitts-walkthrough/
How Supercritical CO2 Working Fluid Can Increase Power Plant Efficiency
?w=800"/>Using steam to produce electricity or perform work via steam turbines has been a thing for a very long time. Today it is still exceedingly common to use steam in https://hackaday.com/2025/04/22/how-supercritical-co2-working-fluid-can-increase-power-plant-efficiency/
eInk PDA Revisited
?w=800" alt=""/>In the dark ages, before iOS and Android phones became ubiquitous, there was the PDA. These handheld computers acted as simple companions to a computer and could often handle calendars, https://hackaday.com/2025/04/22/eink-pda-revisited/
DIY Record Cutting Lathe is Really Groovy
?w=800" alt=""/>Back in the day, one of the few reasons to prefer compact cassette tape to vinyl was the fact you could record it at home in very good fidelity. Sure, https://hackaday.com/2025/04/22/diy-record-cutting-lathe-is-really-groovy/
https://hackaday.com/2025/04/22/diy-record-cutting-lathe-is-really-groovy/
British Wartime Periscope: a Peek Into the Past
?w=800" alt="British wartime periscope on a workbench"/>We all know periscopes serve for observation where there’s no direct line-of-sight, but did you know they can allow you to peer through history? That’s what [msylvain59] documented when he https://hackaday.com/2025/04/22/british-wartime-periscope-a-peek-into-the-past/
https://hackaday.com/2025/04/22/british-wartime-periscope-a-peek-into-the-past/
What’s Sixty Feet Across and Superconducting?
?w=800" alt="The central solenoid taking shape in the ITER assembly hall."/>What’s sixty feet (18.29 meters for the rest of the world) across and superconducting? The International Thermonuclear Experimental Reactor (ITER), and probably not much else. The last parts of the https://hackaday.com/2025/04/22/whats-sixty-feet-across-and-superconducting/
https://hackaday.com/2025/04/22/whats-sixty-feet-across-and-superconducting/
The Most Printable 3D Printer Yet
?w=800" alt="A 3D printer frame made of red plastic is shown on the left-hand side of the image. On the right-hand side, there is a large motor with a plastic frame attached to the frame. Next to the 3D printer, a blue plastic mesh is being fed through a red plastic frame."/>Despite the best efforts of the RepRap community over the last twenty years, self-replicating 3D printers have remained a stubbornly elusive goal, largely due to the difficulty of printing electronics. https://hackaday.com/2025/04/20/the-most-printable-3d-printer-yet/
https://hackaday.com/2025/04/20/the-most-printable-3d-printer-yet/
A 17th Century Music Computer
?w=800" alt=""/>We don’t think of computers as something you’d find in the 17th century. But [Levi McClain] found plans for one in a book — books, actually — by [Athanasius Kirker] https://hackaday.com/2025/04/12/a-17th-century-music-computer/
https://hackaday.com/2025/04/12/a-17th-century-music-computer/