There’s no shortage of Arduino-based clocks around. [Mr_fid’s] clock, though, gets a second look because it is very unique looking. Then it gets a third look because it would be very difficult to read for the uninitiated.

The clock uses three Xs made of LEDs. There is one X for the hours (this is a 24-hour clock), another for the minutes, and one for the seconds. The left side of each X represents the tens’ digit of the number, while the right-side is the units.

But wait… even with two segments on each side of the X, that only allows for numbers from 0 to 3 in binary, right? [Mr_fid] uses another dimension–color–to get around that limitation. Although he calls this a binary clock, it is more accurately a binary-coded-decimal (BCD) clock. Red LEDs represent the numbers one to three. Green LEDs are four to six. Two blue segments represent seven to nine. It sounds complicated, but if you watch the video, below, it will make sense.

This isn’t [Mr_fid’s] first clock. He is using a DS1307 real time clock module to make up for the Arduino’s tendency to drift. Even if you aren’t interested in the clock, the mounting of the LEDs with plastic–and the issues he had isolating them from each other–might come in handy in other displays.

We’ve seen a lot of Arduino clocks over the years, including some that talk. We’ve even seen some that qualify as interactive furniture, whatever that is.

[Diego Marino] and his colleagues at the Politecnico di Torino (Polytechnic University of Turin, Italy) designed a prototype that allows for patients with motor deficits, such as spinal cord injury (SCI), to do rehabilitation via Functional Electrical Stimulation. They devised a system that records and interprets muscle signals from the physiotherapist and then stimulates specific muscles, in the patient, via an electro-stimulator.

The acquisition system is based on a BITalino board that records the Surface Electromyography (sEMG) signal from the muscles of the physiotherapist, while they perform a specific exercise designed for the patient’s rehabilitation plan. The BITalino uses Bluetooth to send the data to a PC where the data is properly crunched in Matlab in order to recognize and to isolate the muscular activity patterns.

After that, the signals are ‘replayed’ on the patient using a relay-board connected to a Globus Genesy 600 electro-stimulator. This relay board hack is mostly because the Globus Genesy is not programmable so this was a fast way for them to implement the stimulator. In their video we can see the muscle activation being replayed immediately after the ‘physiotherapist’ performs the movement. It’s clearly a prototype but it does show promising results.

It reminds us of the Myoelectric Hand, with humans instead. We featured an EMG tutorial a while back for those curious about this topic. Without taking the merit out of excellent and needed medical research, we all wait for the day that all our bio-signals can be easy read and translated to, let’s say, a huge avatar robot like METHOD-2. Right? Right?…

WiFi and Bluetooth were never meant to be the radios used by a billion Internet of Things hats, umbrellas, irrigation systems, or any other device that makes a worldwide network of things interesting. The best radio for IoT is something lightweight which operates in the sub-Gigahertz range, doesn’t need a lot of bandwidth, and doesn’t suck down the power like WiFi. For the last few years, a new low-power wireless communication standard has been coming on the scene, and now this protocol — LoRa — will soon be available in an Arduino form factor.

The Primo, and NRF

It’s not LoRa, but the Arduino Primo line is based on the ESP8266 WiFi chip and a Nordic nRF52832 for Bluetooth. The Primo comes in the ever-familiar Arduino form factor, but it isn’t meant to be an ‘Internet of Things’ device. Instead, it’s a microcontroller for devices that need to be on the Internet.

Also on display at CES this year is the Primo Core which we first saw at BAMF back in May. It’s a board barely larger than a US quarter that has a few tricks up its sleeve. The Primo Core is built around the nRF52832, and adds humidity, temperature, 3-axis magnetometer and a 3-axis accelerometer to a square inch of fiberglass.

The Primo Core has a few mechanical tricks up its sleeve. Those castellated pins around the circumference can be soldered to the Alice Pad, a breakout board that adds a USB port and LiPo battery charger.

LoRa

Also on deck at the Arduino suite were two LoRa shields. In collobration with Semtech, Arduino will be releasing the pair of LoRa shields later this year. The first, the Node Shield, is about as simple as it can get — it’s simply a shield with a LoRa radio and a few connectors. The second, the Gateway Shield, does what it says on the tin: it’s designed to be a gateway from other Arduino devices (Ethernet or WiFi, for example) to a Node shield. The boards weren’t completely populated, but from what I could see, the Gateway shield is significantly more capable with support for a GPS chipset and antenna.

A partnership with Cayenne and MyDevices

Of course, the Internet of Things is worthless if you can’t manage it easily. Arduino has struck up a partnership with MyDevices to turn a bunch of low-bandwidth radio and serial connections into something easy to use. Already, we’ve seen a few builds and projects using MyDevices, but the demos I was shown were extremely easy to understand, even if there were far too many devices in the room.

All of this is great news if you’re working on the next great Internet of Things thing. The Primo Core is one of the smallest wireless microcontroller devices I’ve seen, and the addition of LoRa Arduino shields means we may actually see useful low-bandwidth networks in the very near future.

We’ll admit it: we sometimes overcomplicate things. Look at [Peter Weissbrod’s] automated cat feeder, for example. It isn’t anything more than a bottle, a servo, some odds and ends, and an Arduino. However, it lets him sleep in without his cat waking him for service.

We looked at the code and thought, “This thing will just dispense food all the time! That’s not what you want!” Then we looked closer. [Peter] uses a common household timer to just turn the device on in the morning, let it run for a bit, and then turns it off. You can see a video of the mechanism, below.

Honestly, we have mixed feelings. As we are sure someone’s already quit reading to comment: you don’t really need an Arduino for this. If it were doing the timing, that might make it more justifiable. Or perhaps have it sense daylight to feed in the morning. Still, Arduinos are cheap (we just picked up some tiny Pro’s for about $3) and it is a more flexible arrangement than, say, a 555 driving the servo.

We have seen many cat feeders over the years. Some of them use custom components. Others use whatever you have on hand (including another kitchen timer). However you do it, one thing is clear: When the aliens come and observe life on Earth, they will doubtless conclude that the cats are in charge.

Trolling eBay for parts can be bad for your wallet and your parts bin. Yes, it’s nice to be well stocked, but eventually you get to critical mass and things start to take on a life of their own.

This unconventional Arduino-based FM receiver is the result of one such inventory overflow, and even though it may take the long way around to listening to NPR, [Kevin Darrah]’s build has some great tips in it for other projects. Still in the mess-o-wires phase, the radio is centered around an ATmega328 talking to a TEA5767 FM radio module over I²C. Tuning is accomplished by a 10-turn vernier pot with an analog meter for frequency display. A 15-Watt amp drives a pair of speakers, but [Kevin] ran into some quality control issues with the amp and tuner modules that required a little extra soldering as a workaround. The longish video below offers a complete tutorial on the hardware and software and shows the radio in action.

We like the unconventional UI for this one, but a more traditional tuning method using the same guts is also possible, as this retro-radio refit shows.

It’s an ambitious build for sure — you don’t start with $500 worth of wood if you don’t intend for the finished product to dazzle. And this 240-pixel touch-sensitive light box coffee table does indeed dazzle.

Sometimes when we see such builds as these, fit and finish take a back seat to function. [dasdingo89] bucks that trend with a nicely detailed build, starting with the choice of zebrawood for the table frame. The bold grain and the frosted glass top make for a handsome table, but what lurks beneath the glass is pretty special too. The 240 WS2812 modules live on custom PCBs, each thoughtfully provided with connectors for easy service. There’s also an IR transmitter-receiver pair on each board to detect when something is placed over the pixel. The pixel boards are connected to custom-built shift register boards for the touch sensors, and an Arduino with Bluetooth runs the whole thing. Right now the table just flashes and responds to hand gestures, but you can easily see this forming the basis of a beautiful Tetris or Pong table.

This build reminds us a little of this pressure-sensitive light floor we featured recently, which also has some gaming possibilities. Maybe [dasdingo89] and  [creed_bratton_] should compare notes and see who can come up with the best games for their platform.

[via r/DIY and a tip from emptycanister]

Finding a product that is everything you want isn’t always possible. Making your own that checks off all those boxes can be. [Peter Clough] took the latter route and built a small Bluetooth speaker with an LED visualization display that he calls Magic Box.

A beefy 20W, 4Ohm speaker was screwed to the lid of a wooden box converted to the purpose. [Clough] cut a clear plastic sheet to the dimensions of the box, notching it 2cm from the edge to glue what would become the sound reactive neopixel strip into place — made possible by an electret microphone amplifier. There ended up being plenty of room inside the speaker box to cram an Arduino Pro Mini 3.3V, the RN-52 Bluetooth receiver, and the rest of the components, with an aux cable running out the base of the speaker. As a neat touch, neodymium magnets hold the lid closed.

We gotta say, a custom speaker with LED visualization makes for a tidy little package — aside from the satisfaction that comes from building it yourself.

Depending on your particular situation, you may even opt to design a speaker that attaches to a magnet implanted in your head.

[via /r/DIY]

I’m sure many of us remember building toy car race tracks as kids, racing the cars, and then arguing over which car came in first and who cheated because they let go of their car too soon. Ah, good times. [Phil] wanted to create a drag strip race track for his son to introduce him to die-cast cars. The only commercial drag strip [Phil] could find didn’t have an electronic start gate or a timer, so he created his own with the help of an Arduino, a servo, and some light dependent resistors.

The Arduino controls everything, the button input, the light sensor input, and the servo. A button press tells the Arduino to start the race by pulling the start gate down and starting the timer. When the light sensor is covered, the timer for that lane stops. The time is shown for each lane using a different colored 4-digit 7-segment LED.

There were a couple of problems that had to be solved. The servo launching the cars was pulling too much power when activated so that the IR LEDs used at the finish line would dim enough to trigger before the race had even begun! [Phil]’s article goes over these issues and his design ideas as he built the track.

It’s a simple build that should provide hours of fun for [Phil]’s son and his friends over the years and will hopefully put to rest any arguments over who won. There are lots of photos in [Phil]’s article, as well as several videos showing off how things work and at the end of the article, he includes the code he used to control everything. This would be a great surprise for any nieces and nephews coming to visit over the holidays — you might want to wait for final assembly and include them in the fun!

If you like these kind of projects, we’ve seen a similar Hot Wheels timing system, and a different kind of race track based on a turntable system.

[Florian] has been putting a lot of work into VR controllers that can be used without interfering with a regular mouse + keyboard combination, and his most recent work has opened the door to successfully emulating a Vive VR controller in Steam VR. He uses Arduino-based custom hardware on the hand, a Leap Motion controller, and fuses the data in software.

We’ve seen [Florian]’s work before in successfully combining a Leap Motion with additional hardware sensors. The idea is to compensate for the fact that the Leap Motion sensor is not very good at detecting some types of movement, such as tilting a fist towards or away from yourself — a movement similar to aiming a gun up or down. At the same time, an important goal is for any added hardware to leave fingers and hands free.

[Florian]’s DIY VR hand controls emulate the HTC Vive controllers in Valve’s Steam VR Tracking with a software chain that works with his custom hardware. His DIY controller doesn’t need to be actively held because by design it grips the hand, leaving fingers free to do other tasks like typing or gesturing.

Last time we saw [Florian]’s work, development was still heavy and there wasn’t any source code shared, but there’s now a git repository for the project with everything you’d need to join the fun. He adds that “I see a lot of people with Wii nunchucks looking to do this. With a few edits to my FreePIE script, they should be easily be able to enable whatever buttons/orientation data they want.”

We have DIY hardware emulating Vive controllers in software, and we’ve seen interfacing to the Vive’s Lighthouse hardware with DIY electronics. There’s a lot of hacking around going on in this area, and it’s exciting to see what comes next.

Space. The final frontier. Unfortunately, the vast majority of us are planet-locked until further notice. If you are dedicated hobbyist astronomer, you probably already have the rough positions of the planets memorized. But what if you want to know them exactly from the comfort of your room and educate yourself at the same time? [Shubham Paul] has gone the extra parsec to build a Real-Time Planet Tracker that calculates their locations using Kepler’s Laws with exacting precision.

An Arduino Mega provides the brains, while 3.5-turn-pan and 180-degree-tilt servos are the brawn. A potentiometer and switch allow for for planet and mode selection, while a GPS module and an optional MPU9250 gyroscope/magnetometer let it know where you are. Finally a laser pointer shows the planet’s location in a closed room. And then there’s code: a lot of code.

The hardware side of things — as [Shubham Paul] clarifies — looks a little unfinished because the focus of the project is the software with the intent to instruct. They have included all the code they wrote for the RTPT, providing a breakdown in each section for those who are looking to build their own.

There is an extra step to auto-align the RTPT to north, otherwise you’ll have to do so manually. But [Shubham Paul] has designed it so that even if you move the tracker about, the RTPT will readjust its calculations in real time. Each part of the project includes a wealth of related information beyond simple instructions to adequately equip any prospective builders.

This hack gets the job done. If it’s looks you’re after, an artistic expression of maker skills and astronomy can be seen in this planetary map that relies on persistence of vision.