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.
There’s a new development board in town from Adafruit, and it’s called the CLUE. This tiny board can be programmed in Arduino or CircuitPython, and it is absolutely stuffed with sensors and functionality, including Bluetooth. It’s essentially a BBC Micro:bit with more sensors, a screen, and a much beefier processor. Sound interesting? Let’s get out the magnifying glass and take a look, shall we?
(Editor’s note: Adafruit ran out of the first alpha run of the hardware. While we didn’t run into any bugs, the next versions will presumably have even fewer, but will also cost $40 instead of $30. That said, they’re giving out 3,000 of them to attendants of PyCon in April, so you might also get your hands on one that way.)
First and foremost, there’s the form factor — if that bottom edge looks familiar, that’s because the CLUE is designed to work with micro:bit robot kits and anything else with that edge connector, like the CRICKIT for micro:bit, or the Bit:Bot from Seeed Studios. This is big news for the micro:bit ecosystem, and not just because the CLUE brings tons of sensors and a screen to the scene, although a 1.3″ screen at 240×240 resolution is nothing to sneeze at.
The main brain is a Nordic nRF52840, so you can pair it to your phone and stream your collected data. Or, use it to get two CLUE boards talking to each other. This is a major upgrade from the micro:bit’s nRF51822 — the CLUE is four times faster, has four times the flash memory, and has sixteen times as much RAM. We hope someone can find a way to make them into short-range messaging machines with Q10 keyboards.
If you can’t grow your own synesthesia, buying electronics to do it for you is fine. Such is the case with the CHROMATIC by [Xavier Gazon], an artist who turns all kinds of electronics into circuit-bent musical art pieces. His project turns an old Philips Music 5120 turntable into a colorful MIDI sequencer, inspired by older 20th century instruments such as the Optophonic Piano and the Luminaphone.
The CHROMATIC uses colored pucks placed on a converted turntable to perform a looping sequence of chords in a given musical scale, generating MIDI data as output. Where its inspirations used primitive optics as their medium, this project employs a Teensy microcontroller and two modern optical sensors to do the work. One of these is a simple infrared sensor which tracks a white spot on the edge of the turntable, generating a MIDI clock signal to keep everything quantized and in sync. The other is a color sensor mounted on the tone arm, which can tell what color it sees and the height of the arm from the turntable.
While the instrument is still in beta testing phase details on how notes are generated aren’t yet given, though the general idea is that they are dictated by the color the tone arm sees and its position above the platter. Moving the tone arm changes which pucks it tracks, and the speed of the turntable can also be adjusted, changing how the melody sounds.
[XenonJohn] dabbles in cryptocurrency trading, and when he saw an opportunity to buy an RGB color sensor, his immediate thought — which he admitted to us would probably not be the immediate thought of most normal people — was that he could point it to his laptop screen and have it analyze the ratio of green (buy) orders to red (sell) orders being made for crypto trading. In theory, if at a given moment there are more people looking to buy than there are people looking to sell, the value of a commodity could be expected to go up slightly in the short-term. The reverse is true if a lot of sell orders coming in relative to buy orders. Having this information and possibly acting on it could be useful, but then again it might not. Either way, as far as out-of-left-field project ideas go, promoting an RGB color sensor to Cryptocurrency Trading Advisor is a pretty good one.
Since the RGB sensor only sees what is directly in front of it, [XenonJohn] assembled a sort of simple light guide. By enclosing the area of the screen that contains orders in foil-lined cardboard, the sensor can get a general approximation of the amount of red (sell orders) versus green (buy orders). The data gets read by an Arduino which does a simple analysis and sends alerts when a threshold is crossed. He dubbed it the Crypto-Eye, and a video demo is embedded below.
The project has been in gestation in [Karl]’s mind, on and off, for 10 years or so. The big problem centered around reliably separating out one M&M at a time from a hopper of many. From time to time, [Karl] would speak with other builders using similar techniques to his failed experiments, who often reported that the secret to their machine’s reliability was… careful video editing. It was only when a parts sorter flashed across the Hackaday feed that [Karl] found the mechanism that would work to make his project a reality.
Now that the individual candies could readily be separated and fed through a machine, the rest of the project came together quickly. A color sensor was combined with servos and a stepper motor to duct M&Ms into separate flasks.
The real value of this build, however, is in the overall attention paid to the aesthetics of the final product. The device was built to be a kinetic sculpture, able to run reliably with the minimum of attention at the behest of even an untrained user. By carefully optimising the mechanisms inside and building an attractive enclosure, [Karl] has developed something we’d be proud to show off in a living room.
It combines elements from LEGO Mindstorms with regular blocks in order to make music with color. A different music sample is assigned to each of five colors: red, blue, green, yellow, and white. The blocks are attached to spokes coming off of a wheel made with NXT an EV3. As the wheel turns, the blocks pass in front of a fixed color sensor that reads the color and plays the corresponding sample. The samples are different lengths, so changing the speed of the wheel makes for some interesting musical effects.
As you’ll see in the short video after the break, [Rare Beasts] starts the wheel moving slowly to demonstrate the system. Since the whole thing is made of LEGO, the blocks are totally modular. Removing a few of them here and there inserts rests into the music, which makes the result that much more complex.
[Paul] participated in a hackathon at work and created a hack to help solve what was ultimately a people problem. A soda fridge at work wasn’t getting refilled when empty. Instead of trying to make people less lazy, [Paul] went with making the fridge more needy.
The first thing [Paul] did was make a soda fridge refill sensor from a scale. As the fridge got emptier, it got lighter. The scale senses that and can decide it’s time for a refill. The only part missing was how to read the output from the scale. To do that, he took an unusual approach. Continue reading “Soda Fridge Hack To Fix A Lazy People Problem”→