The Coin Cell Emulator CR2016/CR2032 by [bobricius] homes in on a problem some hardware developers don’t realize they have: when working on hardware powered by the near-ubiquitous CR2016 or CR2032 format 3V coin cells, power can be a bit troublesome. Either the device is kept fed with coin cells as needed during development, or the developer installs some breakout wires to provide power from a more convenient source.
[bobricius]’s solution to all this is a small PCB designed to be inserted into most coin cell holders just like the cell itself. It integrates a micro USB connector with a 3V regulator for using USB as an external power source. The board also provides points for attaching alligator clips, should one wish to conveniently measure current consumption. It’s a tool with a purpose, and cleverly uses the physical shape of the PCB itself as an integral part of the function, much like another of [bobricius]’s projects: the Charlieplexed 7-segment LED display.
Just for a second, let’s perform a little engineering-based thought experiment. Let’s design a guitar tuner. First up, you’ll need a 1/4″ input, and some op-amps to get that signal into a microcontroller. In the microcontroller, you’re going to be doing some FFT. If you’re really fancy, you’ll have some lookup tables and an interface to switch between A440, maybe A430, and if you’re a huge nerd, C256. The interface is simple enough — just use a seven-segment display and a few LEDs to tell the user what note they’re on and how on-pitch they are. All in all, the design isn’t that hard.
Now let’s design a tuner for blind musicians. This makes things a bit more interesting. That LED interface isn’t going to work, and you’ve got to figure out a better way of telling the musician they’re on-pitch. This is the idea of [Pepijn]’s Accessible Guitar Tuner. It’s a finalist in The Hackaday Prize Assistive Technology round, and a really interesting problem to solve.
Most of [Pepijn]’s tuner is what you would expect — microcontrollers and FFT. The microcontroller is an ATMega, which is sufficient enough for a simple guitar tuner. The real trick here is the interface. [Pepijn] modulating the input from the guitar against a reference frequency. The difference between the guitar and this reference frequency is then turned into clicks and played through headphones. Fewer clicks mean the guitar is closer to being in tune.
This is one of those projects that’s a perfect fit for the Hackaday Prize Assistive Technology round. It’s an extremely simple problem to define, somewhat easy to build, and very useful. That doesn’t mean [Pepijn] isn’t having problems — he’s having a lot of trouble with the signal levels from a guitar. He’s looking for some help, so if you have some insights in reading signals that range from tiny piezos to active humbuckers, give him a few words of advice.
Rehabilitating brain injuries where a patient’s sense of balance has been compromised is no easy task. Current solutions only trigger when the patient reaches a threshold and by then, it may already be too late for a graceful recovery. [Simon Merrett]’s SoleSense is being designed to give continuous feedback like a stock humans innate sense of balance. Therapists hope this will aid recovery by more closely imitating what most of us grew up with.
SoleSense relies on capacitive sensors arranged under the feet to know where the patients are placing their weight. [OSHPark] is providing the first round of flexible PCBs so some lucky sole is going to get purple inserts.
Outside of recovery, devices like this can teach better posture or possibly enhance a fully functioning sense of balance. That could improve physical performance. Who knows, we are finding new ways of perceiving the world all the time.
The loss of memory is an extremely difficult situation, not just for those afflicted, but also for immediate family, close friends, and care givers. With no cure available for dementia, providing care is an extremely demanding task for everyone involved – both mentally and physically. Patients are unable to retain recent events and information, but will most likely be able to recall some amount of past memories. This presents serious challenges when they encounter “modern” technology and cannot figure out how to use and operate everyday devices that normal people take for granted.
[rosswesleyporter]’s Dad had trouble using modern iPods and CD players, so he built DQMusicBox — a Dementia friendly music player. It’s very simple interface resembling a radio from half a century ago. There are just two large, clearly marked rotary dials — one for Volume, the other for Songs, and a headphone socket. The inspiration came from a very moving documentary called “Alive Inside” which explores how music brings extreme joy to people with dementia.
The device is built around a Raspberry Pi, enclosed in a laser cut enclosure and requires no soldering — making it easy for anyone to build one for themselves using easily available parts. The Raspberry Pi runs on a lightweight, optimized version of Raspbian called DietPi. The music playback is handled by VLC ensuring support for a large number of music formats. A Python script looks for music files, sets up the VLC-NOX player and handles knob and button events. A bundled image file for the software includes everything needed to get it running, making setup easy and quick. Since Raspberry Pi’s are prone to OS corruption when power is disconnected without performing a proper shutdown, [Ross] uses write protection on the SD-card and walks you through the process of how it works.
Between his Project page, Github and DQMusicBox website, you will be able to get all the information needed to replicate this excellent project. And for his next version, he already has a few ideas for improvement and would like to hear if other hackers have suggestions.
This is the type of crowd that’s famous for building their own test equipment. If you need a way to program a flash chip, don’t go out and buy one — you can just build one. Need a spectrum analyzer? You can build that out of copper clad board. For his Hackaday Prize entry, [oakkar7] is building an optical power meter, capable enough to do futzy fiber work, but still completely DIY.
When you get into networking and telecom connections that don’t begin with the letters ‘RJ’, you start to stumble upon SPF transceivers. These ‘small form factor pluggable’ devices are little modular transceivers capable of handling fiber, Gigabit Ethernet, and other slightly weirder bit pipes. When used with fiber, they can measure optical power in dBm and watts, and can be debugged by a UART.
[oakkar]’s optical power meter uses these SPF transceivers, tied together with a fairly simple circuit consisting of an Arduino, a few tact switches, a Nokia LCD, and an FTDI UART. The key in tying all of this together is an Arduino library for SPF and DDM (Digital Diagnostics Monitoring), giving the user access to all the configuration bits in these transceivers.
While the circuit is simple enough to be built on a piece of perfboard, [oakkar] really knocked it out of the park with the enclosure on this one. With just a little bit of laser cut acrylic and a few standoffs, [oakkar] has a device that actually looks professional, and has most of the capabilities of fancier, more expensive tools.
[Vije Miller]’s Arduino Licorice Launcher is based on the simple and logical premise that one must always have a voice-activated Red Vines catapult in the workshop. When he calls out to the robot, it turns to aim at him and flings a piece of licorice at his head.
The chassis is CNCed out of quarter-inch MDF and the spring-loaded catapult arm is managed by two servos, one to tension the arm and one to secure it until it’s triggered. Third and fourth servos aim the catapult and dispense another piece of licorice from the magazine. His robot adapts a radio homing technique [Vije] learned about from RoboWarner, which allows a robot to track a moving RF signal.
[Vije]’s first prototype uses an Arduino Uno connected to a serial port on a PC, but he hopes to acquire an MKR1000 WiFi module, which combines a Arduino Zero with WiFi. Already, this Red Vines launcher is a complete success; the marketing team at Red Vines sent him a huge pile of swag and free licorice for his efforts. You can check out [Vije]’s promo video of the project below.
The Nokia 3210 is the greatest cell phone ever made. The battery lasted for days, custom color covers were available at every mall kiosk, it had the Snake game, and the chassis for this phone was finely crafted out of the crust of neutron stars. It was indestructible; it is the reason we now appreciate technology over more impermanent concepts like relationships and love.
For his Hackaday Prize entry, [Bastian] is bringing the Nokia 3210 into this century. He’s designing a circuit board with the same footprint, the same button layout, and a better screen that drops right into the lovely plastic enclosure of the 3210.
The current BOM for the upgraded 3210 includes an STM32 F7 microcontroller, which is more or less the current top of the line ARM micro you can get. For wireless, [Bastian] is using an A7 GSM/GPRS module and an ESP8266 for a little bit of WiFi. For a dumbphone, this is ludicrously overpowered. Provided [Bastian] gets a prototype up and running, there will be some interesting applications for a device this powerful in a package this indestructible.
One of the things [Bastian] has been butting his head against with this project is KiCad. Microvias don’t work like they should in KiCad — they’re restricted to the outer layers only. This is a problem for routing a complex board like this, so [Bastian] wrote a patch that gives KiCad an ‘I know what I’m doing mode’ for microvias everywhere.
This is truly the spirit of The Hackaday Prize: not only is [Bastian] building something ridiculous, he’s also creating the tools to do it.