When you’re a kid, remote control cars are totally awesome. Even if you can’t go anywhere by yourself, it’s much easier to imagine a nice getaway from the daily grind of elementary school if you have some wheels. And yeah, R/C cars are still awesome once you’re an adult, but actual car-driving experience will probably make you yearn for more realism.

What could be more realistic and fun than an active suspension? Plenty of adults will never get the chance to hit the switches in real car, but after a year of hard work, [snoopybg] is ready to go front and back, side to side, and even drift in this super scale ’63 Oldsmobile Dynamic 88 wagon. We think you’ll agree that [snoopybg] didn’t miss a detail — this thing makes engine noises, and there are LEDs in the dual exhaust pipes to simulate flames.

An Arduino reads data from a triple-axis accelerometer in real time, and adjusts a servo on each wheel accordingly, also in real time, to mimic a real car throwing its weight around on a real suspension system. If that weren’t cool enough, most of the car is printed, including the tires. [snoopybg] started with a drift car chassis, but even that has been hacked and drilled out as needed.

There are a ton of nice pictures on [snoopybg]’s site if you want to see what’s under the hood. We don’t see the code anywhere, but [snoopybg] seems quite open to publishing more details if there is interest out there. Strap yourself in and hold on tight, because we’re gonna take this baby for a spin after the break.

If this is all seems a bit much for you, but you’ve got that R/C itch again, there’s a lot to be said for upgrading the electronics in a stock R/C car.

Via r/duino

[Gurpreet] fell in love with the peaceful, floaty theme from the Avatar series and bought a kalimba so he could hear it resonate through his fingertips. He soon realized that although it’s nice to play the kalimba, it would be a lot cooler if it played itself. Then he could relax and enjoy the music without wearing out his thumbs.

After doing a bit of experimentation with printing tine-plucking extensions for the servo horns, [Gurpreet] decided to start the design process by mounting the servos on a printed base. The servos are slotted into place by their mounting tabs and secured with hot glue. We think this was a good choice — it’s functional and it looks cool, like a heat sink.

[Gurpreet]’s future plans include more servos to pluck the rest of the tines, and figuring out how feed it MIDI and play it real time. For the demo after the break, [Gurpreet] says he lapel mic’d the kalimba from the back and cut out the servo noise with Audacity, but ultimately wants to figure out how to quiet them directly. He’s going to try lubing the gears and making a sound-dampening enclosure with foam, but if you have any other ideas, let him know down below.

We don’t see too many kalimba projects around here, but here’s one connected to a Teensy-based looper.

Via [r/arduino]

There’s a trend in corporate America that has employees wear a step counter — technically a pedometer — and compete in teams to see who can get the most number of steps. We wonder how many people attach the device to an electric drill and win the competition easily. However if you want to do your own measurements, [Ashish Choudhary] has plans for making a pedometer with an Arduino. The device isn’t tiny, but as you can see in the video below it seems to work.

For the extra size, you do get some features. For one, there is a 16×2 LCD display and an ADXL335 accelerometer, and you can probably imagine some other cool features for such a device.

The Arduino computes the magnitude of the acceleration, and if it exceeds a certain threshold it adds a step to the step count. Honestly, this is a fun project but it cries out for a more compact form factor. An ESP8266 for example could ditch the display and connect via WiFi to your phone. Then again, your phone can probably do the same job, as could not to mention many smartwatches. But those don’t have nearly as much geek cred as this project.

This is a little large for a hamster. On the other hand, there’s plenty you can do with the accelerometer after you’ve had enough fun counting steps.

When you read “Arduino wristwatch”, you fall into the trap of envisioning an Arduino UNO clumsily strapped to someone’s wrist. [Marijo Blažević’s] creation is much more polished than that. A round circuit board holds two surface mount ICs and 12 LEDs. The whole thing looks nice fit snugly inside of a watch body. It isn’t a Rolex, but it does have considerable geek cred without being unwearable in polite company.

Once IC is an AVR micro, of course. The other is a DS3231 real time clock with built-in crystal. A CR2032 keeps it all running. The main body, the outer ring, the bottom, and the buttons are 3D printed in PLA. The crystal and the band are the only mechanical parts not printed. The bill of materials shows a 36mm crystal and even provides links for all the parts.

You don’t want to run LEDs all the time because it is bad on the battery. When you press the button once, you get one of the LEDs to light to show the hours. Another press reads the minutes in units of 5 minutes. A third press shows you one of five LEDs to show how many minutes to add. For example, if the time is 9:26 you’d get LED 9 (hours), LED 5 for 25 minutes, and the third press would show LED 1 for 1 extra minute. If either of the minute indicators show 12 o’clock, that indicates zero minutes.

The exciting thing, of course, is that you can program it beyond the code on GitHub. Already it can tell time and display the temperature. You don’t have a lot of I/O, but you ought to be able to get some more options and maybe some flashy LED blinking patterns in if you try.

Believe it or not, there’s a $400 toy mp3 player out there for kids. It looks pretty nice, with colorful buttons and a wood console and all, but those features don’t really justify the price tag. [DerThes] wanted one for his 2-year-old anyway, so he made his own ruggedized version for a whole lot less.

The simple and kid-friendly interface lets [DerThes Jr.] choose from one of nine albums to play by pushing one of the candy-colored buttons. The bottom row of buttons handle play/pause and moving through the track list. When mom and dad get tired of listening to whatever the kids are into these days, they can enter the special god mode code to access 99 of their favorite albums.

This baby boombox is built with an Arduino Uno and an Adafruit music maker shield. [DerThes] etched his own PCB to hold the buttons and the pair of shift registers needed to interface them with the Uno. If you’ve never etched before, here’s a good chance to dip your toe in the ferric chloride, because [DerThes] has the transparency in his repo and a line on a nice instructional video.

If you don’t think your toddler is ready to respect a field of momentaries, you could make a jukebox with NFC blocks.

[via Arduino blog]

When [gdarchen] wanted to read some NFC tags, he went through several iterations. First, he tried an Electron application, and then a client-server architecture. But his final iteration was to make a standalone reader with an Arduino and use WebUSB to connect to the application on the PC.

This sounds easy, but there were quite a few tricks required to make it work. He had to hack the board to get the NFC reader’s interrupt connected correctly because he was using a Leonardo board. But the biggest problem was enabling WebUSB support. There’s a library, but you have to change over your Arduino to use USB 2.1. It turns out that’s not hard, but there’s a caveat: Once you make this change you will need the WebUSB library in all your programs or Windows will refuse to recognize the Arduino and you won’t be able to easily reprogram it.

Once you fix those things, the rest is pretty easy. The PC side uses node.js. If you back up a level in the GitHub repository, you can see the earlier non-Arduino versions of the code, as well.

If you want to understand all the logic that went into the design, the author also included a slide show that discusses the three versions and their pros and cons. He did mention that he wanted a short-range solution so barcodes and QR codes were out. He also decided against RFID but didn’t really say why.

NFC business cards are a thing. You can also use them to catch some public transportation.

[Robson Couto] started to get interested in musical projects and as a side effect created downloadable code with simple notation for a good variety of themes, songs, and melodies. They are all for the Arduino and use only the built-in tone() function, but don’t let that distract you. If you look past that, you’ll see that each sketch is a melody that consists of single notes and durations; easily adapted to other purposes or simply used as-is. After all, [Robson] wanted the source of each tune to be easily understood, easily modified, and to have no external dependencies.

All that may sound a bit like MIDI, but MIDI has much more in common with hardware events than music notation because it includes (among other things) note starts and note ends as separate elements. Converting MIDI into a more usable format was a big part of a project that fed Bach music to a neural network and got surprisingly good results.

When doing music projects, sometimes having a recognizable melody represented very simply as notes and durations with only one note at a time can be an awfully handy resource, and you can find them on GitHub. There’s a brief video of the Tetris theme (actual name: Korobeiniki) being played after the break.

Sometimes, a project comes along that makes a good reference design for anyone doing similar work. In this particular case, it’s a DIY USB polygraph-like machine by [Juangg] using an Arduino and sensors on the hardware side, and a Python front end for data visualization. It’s even complete with 3D printed enclosure and sensor elements.

[Juangg] designed it to use three sensors: a pulse sensor, a breath sensor, and one to measure Galvanic Skin Response (GSR). The pulse sensor uses a piezo element pressed against a fingertip to detect changes in pressure resulting from blood flow. It can be picky about placement, but finding sweet spot can yield remarkably good readings. The breath sensor works on a similar principle but uses a 3D printed fixture to hold the sensor between a strap and the subject’s chest, so that breathing in and out can be detected. The GSR sensor is a voltage divider used to measure small changes in skin conductivity. How well does it all work? That depends on what one is looking to get out of it, but the documentation and design files are available from the project page and the GitHub repository if anyone wants a reference for similar work.

The polygraph may have a mixed reputation, but it makes a good project that demonstrates just how messy biometrics can be from an engineering perspective. And in case you missed it, here’s a reminder that Wonder Woman and the polygraph have much more in common than you might realize.

Americans love their coffee. The Brits adore their tea. In South America, the number one way to get through the day is with yerba mate, a tea made from the yerba plant. It is typically shared in a social setting, with one person preparing the beverage for everyone to enjoy. Although caffeine certainly deserves a ceremony, it never needs one. Hit the streets and you’ll see people everywhere with a thermos under one arm, keeping water hot and ready to refill the cup of mate in their hand.

The Stanley vacuum thermos is quite a popular choice for drinkers on the go, but the Argentinian government recently placed new restrictions foreign imports. [Roni Bandini] decided to build a minimum viable mate machine so he always has perfectly hot water on tap.

An Arduino Nano heats the water and displays the rising temperature on an LCD screen. When the temperature is just right, the display asks for your cup. An ultrasonic sensor detects the cup and dispenses a certain amount of water determined in the sketch. Yerba leaves can be used a few times before losing their flavor, so the machine keeps track and lets him know when it’s time to replace them. You can sip on a brief demo after the break.

Let’s say you don’t have perfectly-prepared mate, and it always comes out too hot. That’s better than too cold, but still not ideal. Why not make a temperature-sensing coaster that alerts you when it has cooled to perfection?

Programming is a valuable skill, though one that can be daunting to learn. Throw hardware in the mix, and things ratchet up another level again. However, there are many projects that have sought to reduce the level of difficulty for newcomers. HeyTeddy is a new project that allows users to program an Arduino with voice commands, and the help of on-screen tutorials.

It’s a system that initially sounds cumbersome, but through smart design, is actually quite streamlined. Users can talk to the system, which uses an Amazon Alexa device for natural language voice recognition. This enables HeyTeddy to respond to questions like “how do I use a flex sensor?” as well as direct commands, such as “Set pin 10 to 250”.

The demo video does a great job of demonstrating the system. While the system is not suited to professional development tasks, its has value as an educational tool for beginners. The system is able to guide users through both hardware setup on a breadboard, as well as guide them through tests when things don’t work. Once their experience level builds, code can be exported to the Arduino IDE for direct editing.

It’s a great tool that has plenty of promise to bring many more users into the hardware hacking fold. It’s out of the workshop of [MAKInteract], whose work we’ve seen before. Video after the break.