Fixing The Failure Of The Reevo

The Reevo is a hubless electric bike that launched to considerable fanfare but struggled with hardware shortcomings and a proprietary controller accessible only through an unavailable app. YouTuber Berm Peak undertook a full overhaul, starting with jailbreaking the locked controller — whose PCBs were surprisingly well-labelled, enabling reverse-engineering of its communication protocols. Beyond the firmware, nearly every physical component needed work: shrouds and buttons were overhauled, fasteners replaced, and a digital touch display integrated via the jailbroken interface. Even the brakes required attention. The complete repair methodology and firmware modifications are now published on GitHub for other Reevo owners.

Sources: Hackaday

Pi Pico Puts Bluetooth Keyboards On The I2C Bus

Roberto Alsina’s bt2i2c project converts a Pi Pico W into a Bluetooth-to-I2C keyboard bridge. Once flashed, the Pico pairs with any standard Bluetooth keyboard and relays its keystrokes onto the I2C bus, presenting itself to downstream devices as a BlackBerry BBQ20/BBQ10 keyboard at address 0x1F — a well-documented interface with extensive existing library support. An optional ST7789 display connected over SPI gives visual confirmation of pairing status. With Bluetooth keyboards now connectable to any I2C-capable microcontroller, the project opens doors for writerdeck builds and embedded terminals that lack USB host capability but could benefit from a comfortable wireless keyboard.

Sources: Hackaday

3D Printing A Miniature CoreXY Printer

Alex Yu’s Encore is a self-replicating CoreXY printer built almost entirely from 3D-printed parts, with a 120 mm print bed and every component sized to fit within a 225 mm build volume. The frameless design mounts linear rails directly onto printed side panels, which proved sufficiently rigid without a traditional aluminium extrusion frame. Drive motors are NEMA 17 steppers with sliding-mount belt tensioning; a Bambu-style hotend pairs with a Bowden extruder. Tuning required a stronger hotend cooling fan and redesigned ventilation shroud to resolve thermal issues, but the resulting prints show impressive quality. All design files and documentation are on GitHub.

Sources: Hackaday

Desalinating Seawater With Solar And No Brine

A solar-thermal desalination method that eliminates brine discharge entirely has been demonstrated by Luheng Tang and colleagues in a paper published in Light: Science and Applications. The system uses specially treated wicking panels that draw seawater across their surface, with solar radiation evaporating fresh water while a self-cleaning surface treatment prevents salt crystal accumulation — a key failure mode in earlier designs. Extracted materials including table salt, lithium, gold, and uranium can be recovered as usable byproducts rather than dumped as waste. Tests across multiple ocean sources achieved 74% solar-to-vapor conversion efficiency with nearly 100% salt extraction; scaling to industrial capacity remains the next challenge.

Sources: Hackaday

An Ethernet WiFi Router On A Pi Pico 2W

Matt Deeds demonstrates that the Pi Pico 2W can serve as a functional WiFi-to-Ethernet router using entirely bit-banged 10BASE-T networking — no dedicated Ethernet silicon required. The project, written in Rust as a partial port of an earlier implementation, uses Ethernet magnetics on the physical layer while handling all framing and protocol logic in software. Transmit runs at full 10BASE-T speed; receive achieves around 100 kB/s. For applications where raw throughput is secondary, the Pico may now be the cheapest Ethernet-to-wireless bridge possible. The firmware is available as pico-10base-t-rs on GitHub, showcasing how far the RP2350’s programmable I/O can be pushed.

Sources: Hackaday

Bluetooth Gramophone Has Surprisingly Contemporary Roots

JGJMatt’s project adds Bluetooth audio playback to a vintage gramophone without modifying any of its original mechanicals. The contemporary roots in the title refer to an actual 1920s commercial product — the Dulce-Tone Radio Speaker — which used the same principle: a weak speaker placed under the gramophone needle, using the horn as an amplifier for radio signals. The modern version substitutes a neodymium magnet and voice coil from a 3W speaker, driven by an MH-M38 Bluetooth module, in a 3D-printed needle holder and battery-backed enclosure. The modification is fully reversible, allowing the instrument to play original shellac 78s at any time.

Sources: Hackaday

How Small Can You Make A C Executable?

A simple C program that does nothing but return 0 compiles to a surprisingly bloated 15,816 bytes with gcc defaults. Weineng documents a step-by-step campaign to slash that size: stripping debug info and pre-main boilerplate brings it to 13,632 bytes, aggressive linker flags reduce it to 8,704, removing error-handling sections yields 4,320, and cutting dynamic memory allocation overhead gets to 400 bytes — a 97% reduction from the default build. The write-up is a practical guide to compiler and linker flags many developers have never reached for, with techniques applicable to embedded systems where flash space budgets are tight.

Sources: Hackaday

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