Do you need a small weight scale? You can of course buy one, or you could instead make your own 3D-printed device with a load cell and an Arduino, as shown in the below video by MN Maker.

In his setup, the load cell first sends readings to an HX711 breakout board, which converts this analog signal into a digital output that the Nano can easily interpret. The output is displayed on a 0.96” 128×64 OLED, with a button on the back to switch power on and off, and another to tare the scale to zero. 

Code for the project is available here, while print files can be found on Thingiverse.

What really happens when you open the refrigerator door? Sure, you know intuitively that cold air escapes, but just how much? And how fast does the food inside actually heat up? To find out, Ryan Bates came up with his own data logging setup using an Arduino Uno, a custom sensor shield, and a microSD card reader.

His device uses a photoresistor to tell when the door has been opened, as well as a DHT22 temperature/humidity sensor to log the air temperature and door status. Along with this, TMP36 sensors are placed around the fridge to get a more granular look at temperatures, including one attached to a pickle jar. 

The results seen in the video below are quite interesting, and more information on the build can be found here if you’d like to try something similar.

As a kid you may have played Operation, but certainly never anything like this nine-foot-tall version from SPOT Technology. This device is not only impressively large, but assists doctors in their surgical pursuits with a CNC gantry setup to pull out obstructions.

In the game, amateur surgeons control the system using a small arcade cabinet next to the patient (Sergio), moving a magnetic gripper with a joystick and buttons. A camera rides along and transmits images to the cabinet, hopefully leading to a clean extraction. If the gripper isn’t aligned correctly, a button on the plunger reports the doctors error, and Sergio’s nose lights up red to indicate a failed surgery. Two Arduino Megas are implemented, one on the CNC playfield itself, another in the cabinet.

The project will be on display at the Philadelphia Mini Maker Faire on October 6^th if you’d like to see it in person.

Spilled wine may be a hassle to clean up, but you might also observe that it makes interesting patterns. Marketing firm KPS3 had the same sort of thought process when they created “The Santa Maria Swirl Machine” to promote the Santa Maria Valley wine industry.

The machine takes the form of a tabletop display, where a vacuum gripper first picks up a piece of paper and transports it into a clear “swirl area.” A glass is then automatically filled with wine, spun up to speed, and flung at the paper in order to create art. 

Control hardware includes an Arduino Micro and a pair of Raspberry Pi boards, along with cameras are used to stream the process and take a picture of the resulting pattern. If this sounds interesting, you can sign up to make your own spill-art here. You can also read more about the project on TechRepublic:

Visitors to the website can watch the current splash art being made, or register to join the queue to use the service—once their turn arrives, they are given a full-screen view and options to control their creation. Specialized watercolor paper is picked up by a servo equipped with a suction cup attached to a venturi (itself attached to an air compressor), which proceeds to hand off to a custom gripper to hold the paper in place for the wine to be spilled. 

From there, the Arduino-controlled stepper motor turns the lead screw, moving the paper into the splash zone, and fills the glass to the user-selected level, and begins to swirl the glass at the user-selected speed. Once the proper speed is attained, an actuator tips the glass forward, spilling the wine onto the paper. All of this is streamed by two cameras, with the final result photographed by a third. This photo is then processed in Lambda to clean up the photograph, detecting corners, applying filters and branding for the Santa Maria Valley Chamber of Commerce.

You’ve seen barcode scanners register the price for your groceries, and likely in many other applications, but did you ever consider if one could be made into an instrument? Well we now know the answer, thanks to this MIDI guitar by James Bruton.

Bruton’s amazing device presents a matrix of barcodes arranged on the instrument’s four necks, allowing him to select the note to be played with a scanner gun.

The scanned code then triggers a note that’s piped to an output device via an Arduino Mega and MIDI shield. A joystick, spinner, and arcade buttons are also available for functions such as note cutoff, changing the octave, and pitch bends.

Phones are pretty great. Used as telephones, they can save us from bad situations and let us communicate while roaming freely, for the most part. Used as computers, they often become time-sucking black holes that can twist our sense of self and reality. Assuming they pick up when you call, phones are arguably a good thing for kids to have, especially since you can hardly find a payphone these days. But how do you teach kids to use them responsibly, so they can still become functioning adults and move out someday? [Jaychouu] believes the answer is inside of a specialized lockbox.

This slick-looking box has a solenoid lock inside that can be unlocked via a keypad, or remotely via the OBLOQ IoT module. [Jaychouu] added a few features that drive it out of Arduino lockbox territory. To prevent latchkey children from cheating the system and putting rocks (or nothing at all) in the box, there’s a digital weight sensor and an ultrasonic sensor that validate the credentials of the contents and compare them with known values.

Want a basic lockbox to keep your phone out of reach while you work? Here’s one with a countdown timer.

In the heat of the moment, gamers live and die by the speed and user-friendliness of their input mechanisms. If you’re team PC, you have two controllers to worry about. Lots of times, players will choose a separate gaming keyboard over the all-purpose 104-banger type.

When [John Silvia]’s beloved Fang game pad went to that LAN party in the sky, he saw the opportunity to create a custom replacement exactly as he wanted it. Also, he couldn’t find one with his desired layout. Mechanical switches were a must, and he went with those Cherry MX-like Gaterons we keep seeing lately.

This 37-key game pad, which [John] named Eyetooth in homage to the Fang, has a couple of standout features. For one, any key can be reprogrammed key directly from the keypad itself, thanks to built-in macro commands. It’s keyboard-ception!

One of the macros toggles an optional auto-repeat feature. [John] says this is not for cheating, though you could totally use it for that if you were so inclined. He is physically unable to spam keys fast enough to satisfy some single-player games, so he designed this as a workaround. The auto-repeat’s frequency is adjustable in 5-millisecond increments using the up /down macros. There’s a lot more information about the macros on the project’s GitHub.

Eyetooth runs on an Arduino Pro Micro, so you can either use [John]’s code or something like QMK firmware. This baby is so open source that [John] even has a hot tip for getting quality grippy feet on the cheap: go to the dollar store and look for rubber heel grippers meant to keep feet from sliding around inside shoes.

If [John] finds himself doing a lot of reprogramming, adding a screen with a layout map could help him keep track of the key assignments.

If you have a Roomba, you know they are handy. However, they do have a habit of getting into places you’d rather they avoid. You can get virtual walls which are just little IR beacons, but it is certainly possible to roll your own. That’s what [MKme] did and it was surprisingly simple, although it could be the springboard to something more complicated. You can see a video about the build below.

As Arduino projects go, this could hardly be more simple. An IR LED, a resistor and a handfull of code that calls into an IR remote library. If that’s all you wanted, the Arduino is a bit overkill, although it is certainly easy enough and cheap.

We know that’s not much, but we were impressed with some of the other information associated with the project for future directions. For example, there’s this project that adds an ultrasonic sensor to a Roomba using the serial port built under the handle. The interface and protocol for that port is even nicely documented.

That got us thinking. You could probably use some ultrasonic sensors for two-way communication to do custom walls. For example, you could use one to send a set number of pulses per second and have another device on the Roomba to receive them and count. You could program rules like a particular wall is only really a wall between 8 AM and 5 PM, for example.

We’ve seen some people use the Roomba as a general-purpose robot platform. We still wish we could find a sensor in the DigiKey catalog to help avoid this common problem.

LEDs and blinky projects are great, and will likely never fade from our favor. But would you look at this sweeping beauty? This mesmerizing display is made from 36 micro servos with partial Popsicle sticks pasted on the arms. After seeing a huge display with 450 servos at an art museum, [Doug Domke] was inspired to make a scaled-down version.

What [Doug] didn’t scale down is the delightful visuals that simple servo motion can produce. The code produces a three-minute looping show that gets progressively more awesome, and you can stare at that after the break. Behind the pegboard, a single, hardworking Arduino Uno controls three 16-channel PWM controllers that sweep the servos. We like to imagine things other than Popsicle sticks swirling around, like little paper pinwheels, or maybe optical illusion wheels for people with strong stomachs.

You won’t see these in the video, but there are five ultrasonic sensors mounted face-up on the back of the pegboard. [Doug] has optional code built in to allow the servo sticks to follow hand movement. We hope he’ll upload a demo of that feature soon.

Servos can be hypnotic as well as helpful, as we saw in this 114-servo word clock.

Via Arduino blog

A question: if you’re controlling the classic video game Street Fighter with gestures, aren’t you just, you know, street fighting?

That’s a question [Charlie Gerard] is going to have to tackle should her AI gesture-recognition controller experiments take off. [Charlie] put together the game controller to learn more about the dark arts of machine learning in a fun and engaging way.

The controller consists of a battery-powered Arduino MKR1000 with WiFi and an MPU6050 accelerometer. Held in the hand, the controller streams accelerometer data to an external PC, capturing the characteristics of the motion. [Charlie] trained three different moves – a punch, an uppercut, and the dreaded Hadouken – and captured hundreds of examples of each. The raw data was massaged, converted to Tensors, and used to train a model for the three moves. Initial tests seem to work well. [Charlie] also made an online version that captures motion from your smartphone. The demo is explained in the video below; sadly, we couldn’t get more than three Hadoukens in before crashing it.

With most machine learning project seeming to concentrate on telling cats from dogs, this is a refreshing change. We’re seeing lots of offbeat machine learning projects these days, from cryptocurrency wallet attacks to a semi-creepy workout-monitoring gym camera.