Misc Hacks

4165 Articles

Clay Pot MP3 Player Whipped Up With The Freedom-K64F

April 24, 2021 by 13 Comments

In the streaming era, few of us think about MP3s on a day to day basis anymore. Our music collection is managed by warring executives in streaming companies from far-off lands. However, for [vinod], they’re still useful — seeing as he just built himself an MP3 player that fits in a clay pot.

The build is based on the FRDMK64F development board, packing a powerful 120 MHz ARM chip. This has enough grunt to decode MP3s on the fly, using the Helix MP3 decoder library. The MP3s themselves are streamed off an SD card, using the faster SDIO access method rather than relying on slower SPI. Once decoded, the resulting PCM audio data is shifted out via a DAC using the chip’s DMA hardware, allowing for smooth, glitch-free playback. Output to a big woofer is via a 15 W class D amplifier, with the whole rig powered from a USB powerbank.

With all the electronics piled on the back of a big woofer speaker with lashings of hot glue, the final result is quite imposing; all the more so when installed neatly inside a clay pot acting as a bass reflex enclosure. We’ve seen some concrete cast speakers before, but not nearly enough hacker projects in clay. Please rectify this, and inform us once you’ve done so. Thanks in advance — video after the break!

Continue reading “Clay Pot MP3 Player Whipped Up With The Freedom-K64F” →

Modding A Hot Wheels Car Into A Radio Controlled Drift Weapon

April 23, 2021 by 14 Comments

Hot Wheels are some of the most popular diecast toy cars worldwide. The car bodies are faithful recreations of the real thing, though the models are mere stationary playthings. That wasn’t good enough for [Jakarta Diecast Project], who set about modifying a little BMW E30 M3 into an awesome radio-controlled drift car.

The build starts by disassembling the original car, and pulling out the original wheels. The baseplate is then modified to accept a new rear suspension and axle assembly. A small DC motor is mounted to the assembly to drive the rear wheels. A set of front steering knuckles are then installed up front, with their own suspension and hooked up to a tiny servo for steering. Everything’s controlled by a compact off-the-shelf RC receiver, which even features a gyro to help keep the tiny car straight under acceleration. The bodyshell is then stripped of paint, and given a sweet bodykit, before receiving a lurid orange paint job and decals. It’s reattached to the car’s baseplate via magnets, which make taking the car apart easy when service or modifications are required.

While the build doesn’t go into the nitty gritty on some of the harder parts, like the construction of the incredibly complex front knuckles, it’s nonetheless a great guide to building such a tiny and well-presented RC car. In looks and performance, the result trounces typical commercial offerings in the same scale, as you’d expect from such a hand-crafted masterpiece. It may not be the smallest RC car we’ve featured, but it is one of the coolest. Video after the break.

Continue reading “Modding A Hot Wheels Car Into A Radio Controlled Drift Weapon” →

Pi-Based Spectrometer Puts The Complexity In The Software

April 23, 2021 by 43 Comments

Play around with optics long enough and sooner or later you’re probably going to want a spectrometer. Optical instruments are famously expensive, though, at least for high-quality units. But a useful spectrometer, like this DIY Raspberry Pi-based instrument, doesn’t necessarily have to break the bank.

This one comes to us by way of [Les Wright], whose homebrew laser builds we’ve been admiring for a while now. [Les] managed to keep the costs to a minimum here by keeping the optics super simple. The front end of the instrument is just a handheld diffraction-grating spectroscope, of the kind used in physics classrooms to demonstrate the spectral characteristics of different light sources. Turning it from a spectroscope to a spectrometer required a Raspberry Pi and a camera; mounted to a lens and positioned to see the spectrum created by the diffraction grating, the camera sends data to the Pi, where a Python program does the business of converting the spectrum to data. [Les]’s software is simple by complete, giving a graphical representation of the spectral data it sees. The video below shows the build process and what’s involved in calibrating the spectrometer, plus some of the more interesting spectra one can easily explore.

We appreciate the simplicity and the utility of this design, as well as its adaptability. Rather than using machined aluminum, the spectroscope holder and Pi cam bracket could easily be 3D-printer, and we could also see how the software could be adapted to use a PC and webcam.

Continue reading “Pi-Based Spectrometer Puts The Complexity In The Software” →

Turn On Your Lights With A Wave Of A Magic Wand

April 22, 2021 by 14 Comments

Smartphones and voice assistants are the typical way most of us interact with our smart devices around the home, but it doesn’t have to be the only way. [Sam March] wanted things to feel a little more magical – so built a wand to do the job instead.

The wand relies on a DA14531 Bluetooth Low Energy (BLE) system-on-chip, and is paired with what appear to be smart plugs running on the same hardware. With an accelerometer in the wand, it’s able to detect waving motions, and then signal the smartplugs over Bluetooth to switch outlets on or off. As far as the magic side of things is concerned, [Sam] took his lead from [Arthur C. Clarke], who famously stated “Any sufficiently advanced technology is indistinguishable from magic.” Thus, efforts were made to miniaturize the electronics down to a single tiny PCB, allowing it to be secreted inside a turned wooden wand that’s wrapped in leather.

The end result is a fun project that’s also probably useful when [Sam] wants to turn the lights off without getting out of bed. We could imagine that, configured properly to work on a room-by-room basis, it could be useful for guests who don’t know where the light switches are.

If the name sounds familiar, it’s because we’ve heard from [Sam] before – with his great DIY smartwatch build. Video after the break.

Continue reading “Turn On Your Lights With A Wave Of A Magic Wand” →

TR-109 Raspberry Picorder 2 Really Nails The Star Trek Aesthetic

April 22, 2021 by 9 Comments

Star Trek famously showed its medical staff using a multifunctional device by the name of the tricorder. While no such devices are regularly used by current medical staff in this timeline, the concept is nonetheless appealing to fans of the show. [directive0] is one such person, and built himself a replica by the name of the Picorder 2.

Picorder 2 is inspired by the tricorders from Star Trek: The Next Generation. The name is an indication that this isn’t a first attempt; it builds upon an earlier project based on the models from the original series. It’s built with a nifty 3D printed case that folds in half, just like the real deal. Plenty of attention to detail has been invested in the decals and backlit controls to really complete the look.

Inside, a Raspberry Pi Zero W runs the show, paired with a bunch of sensors and accessories to get the job done. The human interface is via capacitive touch, and data is displayed on an ST7735 LCD display for output. The graphing software [directive0] built does a great job of creating a Trekesque aesthetic, displaying data from various in-built sensors, such as temperature, humidity, and barometric pressure. There’s also a low-resolution thermal imaging camera – and it’s hard to get more sci-fi than that.

While we’re a ways off from medically-useful tricorders, it’s nonetheless fun to see replica props that have some life and functionality built into them. The tricorder remains a popular build – we see them pretty regularly! – and we can’t wait to see where the fandom takes them over the next few years.  Video after the break.

Continue reading “TR-109 Raspberry Picorder 2 Really Nails The Star Trek Aesthetic” →

Build Your Own Bluetooth Notification Ticker

April 21, 2021 by 17 Comments

Stock tickers were telegraph-based machines from the 19th century, and quickly fell by the wayside with the advent of computer replacements from the 1960s onwards. However, there’s something charming about small machines that deliver us paper strips of information – as demonstrated by this notification ticker from [DIYprojects] (Russian language, Google Translate link).

The heart of the build is an Arduino Mini, which receives the text content of smartphone notifications via a Bluetooth module hooked up to its serial port. The machine mounts a small roll of paper strip, which is pulled along by a stepper motor fitted with a rubber earbud for added grip. The pen is moved along the paper by a servo using a Lambda mechanism to allow it to move nicely perpendicular to the paper’s direction of travel. Instead of moving the pen up and down, the paper is pushed into the pen by a solenoid mounted underneath.

It’s a fun little project, and one we can imagine being great for educational purposes. It teaches skills required to work with steppers, servos, solenoids and Bluetooth, all at once. It’s a little different from some other pen plotter designs, but the ticker format has a certain charm that’s hard to replicate any other way. Video after the break.

Continue reading “Build Your Own Bluetooth Notification Ticker” →

A Useful Macro Pad For Microsoft Teams

April 20, 2021 by 15 Comments

Working from home has now become de rigeur for many more people around the globe. With it, has sprung up a desire for better controls for streaming and conferencing software. There are plenty of streamdecks on the market, of course, but this isn’t BuyADay, it’s HackADay. Thus, you’ll want to check out this great build for Microsoft Teams by [Build Comics].

The build consists of a series of Cherry MX Silent Red key switches in a 3D printed housing, dedicated to muting audio, switching video, and making and hanging up on calls. Naturally, they’re marked with their individual functions and lit with RGB LEDs for obvious feedback. The keys are read by a Raspberry Pi Pico, which handles USB communication with the PC. AutoHotKey is then pressed into service to make the final link to the Microsoft Teams software. [Build Comics] also worked on a 3D-printed busylight that indicates when they’re on a call; however, thus far it isn’t quite working properly. Jump into the conversation on Github or comment below if you’ve got insight on the problem.

It’s a build that likely saves a lot of hassle when you’re on several calls a day. The mute button is a sure-fire jobsaver on some occasions, and it’s better to have it and not need it, then need it and not have it. We’ve featured work from [Build Comics] before, too – like this excellent vintage meter restoration. Video after the break.

Continue reading “A Useful Macro Pad For Microsoft Teams” →