AvoRipe Takes A Firm Grip On The Ultimate First World Food Problem

March 18, 2020 by Sven Gregori 14 Comments

You don’t have to be an extinct mammal or a Millennial to enjoy the smooth, buttery taste of an avocado. Being psychic on the other hand is definitely an advantage to catch that small, perfect window between raw and rotten of this divaesque fruit. But don’t worry, as modern problems require modern solutions, [Eden Bar-Tov] and [Elad Goldberg] built the AvoRipe, a device to notify you when your next avocado has reached that window.

Taking both the firmness and color of an avocado as indicators of its ripeness into account, the team built a dome holding a TCS3200 color sensor as stand for the avocado itself, and 3D printed a servo-controlled gripper with a force sensor attached to it. Closing the gripper’s arms step by step and reading the force sensor’s value will determine the softness the avocado has reached. Using an ESP8266 as centerpiece, the AvoRipe is turned into a full-blown IoT device, reporting the sensor readings to a smartphone app, and collecting the avocado’s data history on an Adafruit.IO dashboard.

There is unfortunately one big drawback: to calibrate the sensors, a set of nicely, ripe avocados are required, turning the device into somewhat of a chicken and egg situation. Nevertheless, it’s a nice showcase of tying together different platforms available for widescale hobbyist projects. Sure, it doesn’t hurt to know how to do each part from scratch on your own, but on the other hand, why not use the shortcuts that are at our disposal to remove some obstacles — which sometimes might include programming itself.

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Custom Reddit Keyboard Only Needs One Hand

March 17, 2020 by Tom Nardi 12 Comments

Sometimes you might want to browse your favorite social media site while eating a sandwich, or throwing darts, or fending off an attacker with a sword. You know, normal things that might occupy only one of your hands. If you’ve ever found yourself in such a situation, then this custom Reddit keyboard could be for you.

Built by [jangxx], this little board is about as simple as it gets. Even if you aren’t looking for a way to browse /r/cooking while practicing your single-handed egg cracking technique, the same principles could be used to quickly throw together a macro keyboard for whatever your particular needs might be.

Inside the 3D printed enclosure is nothing more exotic than an Arduino Pro Micro and five Cherry MX Red switches. The switches have been wired directly to the GPIO pins on the Arduino, and a simple Sketch takes care of the rest. [jangxx] has written the code in such a way that you can easily define the mapping of USB HID keys to physical switches right at the top of the file, making it easy to reuse for your own purposes.

As simple as this project is, we really like the trouble that [jangxx] went through on the 3D printed key caps. The white up and down arrows allow you to navigate through the posts, and the center key selects the one you want to view. Since it’s for Reddit, naturally the red and blue buttons for rapid voting. When you want to go back to the list of posts, just hit the center button again.

Back in 2011 we saw a dedicated Reddit voting peripheral, but we think the addition of simple navigation keys makes this project a bit more compelling. Incidentally, if you can think of any other reason you might want a one-handed keyboard for browsing Reddit…we definitely don’t want to hear about it.

Watchman Watches You Watching Him Watch You

March 15, 2020 by Kristina Panos 8 Comments

At this point, society has had over three decades to get used to the Blue Man Group. Maybe that’s why we’re less disturbed by [Graham Jessup]’s face-tracking Watchman than we should be. Either that, or it’s because it reminds us of Data from Star Trek: The Next Generation. Frankly, this is just way too cool to be dismissed out of hand as creepy.

The Watchman finds faces via video feed from a camera module positioned in his forehead as a third eye. The camera is connected to a Pi Zero that’s wearing a Google AIY vision bonnet. The Pi translates the face locations into servo positions and feeds them to an Arduino UNO located in the frontal lobe region to move the eyeballs and lids accordingly.

[Graham] had a bit of trouble with tracking accuracy at first, so he temporarily replaced the pupils with 5 mW lasers and calibrated them by tracking a printed stand-in of his head to avoid burning out his retinas.

This project builds on previous work by [Tjahzi] and the animatronic eye movements of [Will Cogley]. We can only imagine how awesome the Watchman would look with a pair of [Will]’s incredibly realistic eyeballs. Either way, we would totally trust the Watchman to defend our modest supply of toilet paper in the coming weeks. Check out a brief demo after the break, and a whole lot more clips on [Graham]’s site.

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This Barometer Looks Mighty Fine, Rain Or Shine

March 13, 2020 by Kristina Panos 14 Comments

Mythological legend has it that Tempestas, the Roman goddess of storms and sudden weather, saved the consul Scipio when his fleet of ships got caught in a storm off of Corsica. In return, she demanded that a temple be dedicated to her.

[SephenDeVos]’ beautiful barometer, dubbed Tempestas II, demands nothing of the viewer, but will likely command attention anyway because it looks so cool. If the weather is anything but clear and sunny, the appropriate sun-obscuring weather actor, be it clouds, more clouds, rain, or lightning will swing into place, blocking out the blue sky in layers, just like real life.

There’s a total of five weather-serving servos, and they’re all controlled by an Arduino Nano through a 16-channel PWM driver. The Nano gets the news from a BMP280 barometric pressure/temperature sensor and drives the servos accordingly.

Nine layers of nicely-decorated Plexiglas® hide the clouds and things in the wings while it’s nice outside. We totally love the way this looks — it’s even pretty on the back, where the sun don’t shine. This one is new and ongoing, so it seems likely that [Sephen] will post the code before the sun sets on this project. In the meantime, check out the demo after the break.

We don’t see too many barometers builds around here — maybe there’s too much pressure. This one tells you to lay off the coffee when the pressure’s too low.

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Slippy Slapper Uselessly Uses All The Arduinos

March 13, 2020 by Kristina Panos 8 Comments

Want to take that annoyingly productive coworker down a notch? Yeah, us too. How dare they get so much done and be so happy about it? How is it possible that they can bang on that keyboard all day when you struggle to string together an email?

The Slippy Slapper is a useless machine that turns people into useless machines using tactics like endless distraction and mild physical violence. It presses your buttons by asking them to press buttons for no reason other than killing their productivity. When they try to walk away, guess what? That’s another slappin’. Slippy Slapper would enrage us by proxy if he weren’t so dang cute.

You’re right, you don’t need an Arduino for this. For peak inefficiency and power consumption, you actually need four of them. One acts as the master, and bases its commands to the other three on the feedback it gets from Slippy’s ultrasonic nostrils. The other three control the slappin’ servos, the speakers, and reading WAV files off of the SD card. Slap your way past the break to see Slippy Slapper’s slapstick demo.

Need to annoy a group of coworkers all at once? Slip a big bank of useless machines into the conference room while it’s being set up.

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Vocal Effects On The Arduino Uno

March 12, 2020 by Lewin Day 14 Comments

When one thinks of audio processing, the mind doesn’t usually leap to an 8-bit micro. Despite this, if you’re looking for some glitchy fun, it’s more than possible, as [Amanda Ghassaei] demonstrates with the Arduino Uno in this 2012 throwback project.

The build is designed for vocal effects, based on the idea of granular synthesis. This is where audio samples are chopped up into small chunks, called “grains”, and manipulated in various ways to make fun sounds. Controls on the box allow the nature of the sound created to be modified by the user.

[Amanda]’s project serves as a great example of what it takes to run audio processing on the Arduino Uno. There’s a guide to using the on-board ADC as a microphone input, as well as the construction of a resistor ladder DAC for output. As a neccessity, this also requires discussion of how to write directly to the ATMEGA’s IO ports, rather than using the slower digitalWrite() function typically used in Arduino projects. There’s plenty of value here for anyone learning to do audio on a microcontroller platform.

Overall, it’s a fun project that serves as a good primer for those keen to dive into digital sound processing. Of course, those looking to kick things up a gear would do well to check out the Teensy Audio Library, too. Video after the break.

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Custom Tibia Keyboard For A Leg Up In The Game

March 11, 2020 by Kristina Panos 10 Comments

[Elite Worm] wrote in to tell us about a cool little keyboard designed to make playing a certain game a whole lot easier. One of the ways you can move your character is with the numpad in directional mode plus Control and Shift, but those are too far apart to drive blindly with one hand. This is all the motivation [Elite Worm] needed to build a custom keyboard with only the essentials.

The keyboard is controlled by an Arduino Pro Micro, which is fairly standard for this type of build — it’s usually that or a Teensy. [Elite Worm] used Cherry MX browns for a nice tactile feel, and added LEDs for a purple-white under-glow. We love the way the printed keycaps turned out, and are impressed because tolerances are notoriously tight for those fruity switch stems.

Starting to think of a few uses for a small custom keypad? This thing is wide open, and [Elite Worm] will even send you the PCB files if you ask nicely. See if you can get past the break without your mouse, and check out the build video while you wait.

Want more flexibility? Just use more switches! Continue reading “Custom Tibia Keyboard For A Leg Up In The Game” →