arduino

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Hassle-Free Classical Conditioning For Honey Bees

October 18, 2017 by 10 Comments

When you’re sick or have a headache, you tend to see things a bit differently. An ill-feeling human will display a cognitive bias and expect the world to punish them further. The same is true of honey bees. They are intelligent creatures that exhibit a variety of life skills, such as decision-making and learning.

It was proven back in 2011 that honey bees will make more pessimistic decisions after being shaken in a way that simulates an attack by varroa destructor mites. The bees were trained to associate a reward of sugar-water with a particular odor and to associate foul-tasting punishment water with another odor—that of formic acid, a common treatment against varroa mites. When a third stimulus created by mixing the two odors was presented, the experimenters found that the aggravated bees were more likely to expect the bad odor. Sure enough, they kept their tongues in their mouths when they smelled the third odor. All the bees that weren’t shaken looked forward to sucking down a bit of sugar-water.

So, how does one judge a honey bee’s response? Whenever their antennae come in contact with something appetizing, they stick out their proboscis involuntarily to have a taste. This is called proboscis extension reflex (PER), and it’s the ingrained, day-one behavior that leads them to suck the nectar out of flower blossoms and regurgitate it to make honey.

[LJohann] is a behavioral biologist who wanted to test the effects of varroa mite treatment on bee-havior by itself, without agitating the bees. He built a testing apparatus to pump odors toward bees and judge their response which is shown in a few brief demo videos after the break. This device enables [LJohann] to restrain a bee, tantalize its antennae with sucrose, and pump a stimulus odor at its face on the cue of an LED and piezo buzzer. A fan mounted behind the bee helps clear the air of the previous scents. We especially like the use of a servo to swing the tube in and out of the bee’s face between tests.

[LJohann] and his colleagues concluded that the varroa mite treatment by itself does not make the bees pessimistic. This is great news for concerned apiarists who might be skeptical about using formic acid in the fight against the honey bee’s worst predator. Check out the brief demo videos after the break.

Hackaday has long been abuzz about bees whether they produce honey or not. We’ve covered many kinds of sweet projects like intelligent hives, remote hive weight monitoring, and man-made bee nest alternatives. Continue reading “Hassle-Free Classical Conditioning For Honey Bees” →

Click Your Heels Thrice, Hail A Cab Home

October 17, 2017 by 21 Comments

If Dorothy from The Wizard of Oz were to wake up in 2017, with her magic Ruby Slippers on her feet, she’d probably believe she had woken up in a magical world. But modern folks will need a little more magic to impress them. Like Clicking your heels thrice to get home with these Uber ruby slippers. [Hannah Joshua] was tasked by her employer to build a quirky maker project. She got an idea when a friend complained about having trouble hailing a cab at the end of a hard day at work.

[Hannah] started with ruby colored slippers with a platform toe and high heels to allow space to stuff in all the magic dust, err, electronic bits. The initial plan was to use an Arduino with a GSM/GPS shield but that would have needed a separate SIM card and data plan for the shoes. Instead, she opted for the 1Sheeld which connects to a smart phone over Bluetooth. The 1Sheeld gets access to all of the smart phone’s sensors including the GPS as well as the data connection. The Arduino and 1Sheeld are put in a cavity carved out in the toe section. The 9 V battery goes inside another cavity in the heel, where an activation switch is also installed. Three LED’s indicate when the shoe is active, the cab request is accepted, and when the cab is on its way.

The code is basic since this one of her first Arduino projects, but it gets the job done. It sends an http request to Uber’s API to request a cab. The destination is hard-coded, so the slippers only allow you to get from your current location to whatever destination is programmed. The GitHub repository provides code, as well as some additional information on construction. [Hannah] has also added notes explaining some of the design choices and things to take care about if you plan to build one of these magic slippers.

We covered the 1Sheeld when it was introduced several years back, and if you get your hands on one, try building this Hand Waving Door Unlocker.

Continue reading “Click Your Heels Thrice, Hail A Cab Home” →

TeensyStep – Fast Stepper Library For Teensy

October 17, 2017 by 27 Comments

The Teensy platform is very popular with hackers — and rightly so. Teensys are available in 8-bit and 32-bit versions, the hardware has a bread-board friendly footprint, there are a ton of Teensy libraries available, and they can also run standard Arduino libraries. Want to blink a lot of LED’s? At very fast update rates? How about MIDI? Or USB-HID devices? The Teensy can handle just about anything you throw at it. Driving motors is easy using the standard Arduino libraries such as Stepper, AccelStepper or Arduino Stepper Library.

But if you want to move multiple motors at high micro-stepping speeds, either independently or synchronously and without step loss, these standard libraries become bottlenecks. [Lutz Niggl]’s new TeensyStep fast stepper control library offers a great improvement in performance when driving steppers at high speed. It works with all of the Teensy 3.x boards, and is able to handle accelerated synchronous and independent moves of multiple motors at the high pulse rates required for micro-stepping drivers.

The library can be used to turn motors at up to 300,000 steps/sec which works out to an incredible 5625 rpm at 1/16 th micro-stepping. In the demo video below, you can see him push two motors at 160,000 steps/sec — that’s 3000 rpm — without the two arms colliding. Motors can be moved either independently or synchronously. Synchronous movement uses Bresenham’s line algorithm to plan motor movements based on start and end positions. While doing a synchronous move, it can also run other motors independently. The TeensyStep library uses two class objects. The Stepper class does not require any system resources other than 56 bytes of memory. The StepControl class requires one IntervallTimer and two channels of a FTM  (FlexTimer Module) timer. Since all supported Teensys implement four PIT timers and a FTM0 module with eight timer channels, the usage is limited to four StepControl objects existing at the same time. Check out [Lutz]’s project page for some performance figures.

As a comparison, check out Better Stepping with 8-bit Micros — this approach uses DMA channels as high-speed counters, with each count sending a pulse to the motor.

Thanks to [Paul Stoffregen] for tipping us off about this new library. Continue reading “TeensyStep – Fast Stepper Library For Teensy” →

Nematoduino: A Roundworm Neural Model On An Arduino

October 13, 2017 by 13 Comments

When it comes to building a neural network to simulate complex behavior, Arduino isn’t exactly the first platform that springs to mind. But when your goal is to model the behavior of an organism with only a handful of neurons, the constraints presented by an Arduino start to make sense.

It may be the most important non-segmented worm you’ve never heard of, but Caenorhabditis elegans, mercifully abbreviated C. elegans, is an important model organism for neurobiology, having had its entire nervous system mapped in 2012. [Nathan Griffith] used this “connectome” to simulate a subset of the diminutive nematode’s behaviors, specifically movements toward attractants and away from obstacles. Riding atop a small robot chassis, the Arduino sends signals to the motors when the model determines it’s time to fire the virtual worm’s muscles. An ultrasonic sensor stands in for the “nose touch” neurons of the real worm, and when the model is not busy avoiding a touch, it’s actively seeking something to eat using the “chemotaxis” behavior. The model is up on GitHub and [Nathan] hopes it provides an approachable platform for would-be neuroroboticists.

This isn’t the first time someone has modeled the nematode’s connectome in silico, but kudos to [Nathan] for accomplishing it within the constraints an Arduino presents.

Continue reading “Nematoduino: A Roundworm Neural Model On An Arduino” →

Build Your Own Wave Tank

October 10, 2017 by 25 Comments

Wave tanks are cool, but it’s likely you don’t have one sitting on your coffee table at home. They’re more likely something you’ve seen in a documentary about oil tankers or icebergs. That need no longer be the case – you can build yourself a wave generator at home!

This build comes to use from [TVMiller] who started by creating a small tank out of acrylic sheet. Servo-actuated paddles are then placed in the tank to generate the periodic motion in the water. Two servos are controlled by an Arduino, allowing a variety of simple and more complex waves to be created in the tank. [TVMiller] has graciously provided the code for the project on Hackaday.io. We’d love to see more detail behind the tank build itself, too – like how the edges were sealed, and how the paddles are hinged.

A wave machine might not be the first thing that comes to mind when doing science at home, but with today’s hardware, it’s remarkable how simple it is to create one. Bonus points if you scale this up to the pool in your backyard – make sure to hit the tip line when you do.

RetroModem For The Commodore 64

October 7, 2017 by 17 Comments

Retrocomputers are fun, but ultimately limited in capability compared to modern hardware. One popular pursuit to rectify this is the connection of early home computers to the Internet. To that end, [que] built the Retromodem for the Commodore 64.

The build starts with a case from an Intel 14.4 modem. A little fast for the Commodore 64 era, but anachronism is charming when done tastefully. Inside is an Arduino with an ethernet module to handle the heavy lifting of carrying packets to the outside world.  [que] took the time to wire up status LEDs for the proper vintage look, which really adds something to the project. They switch on and off to indicate the various settings on the modem – it’s great to see in the video below the break the “HS” LED light up when the baud rate is changed to a higher speed.

The project implements most of the Hayes command set, so you can interface with it over a serial terminal just like it’s 1983. [que] doesn’t go into too many details of how it’s all put together, but for the experienced code warrior it’s a project that could be whipped up in a weekend or two. For a more modern take, perhaps you’d like to hook your C64 up over Wifi instead?

Continue reading “RetroModem For The Commodore 64” →

Arduino Uno Strain Relief

October 7, 2017 by 24 Comments

Do jumper wires pulling out of your Uno have you pulling your hair out? Is troubleshooting loose jumpers making you lose your mind?  Are your projects backing up because of all the time you’ve lost keeping jumper wires secure in your Arduino Uno? Then you need the all new Ardunio Strain Relief Enclosure!

[Jeremy Cook] has had it with loose jumpers pulling out of his Uno, so he designed a case that not only secures the Arduino; it also keeps those dastardly jumper wires from pulling out at the most inconvenient times.

Composed of 3/4 inch thick MDF and 1/8 inch thick polycarbonate, the Arduino Strain Relief enclosure is sure to be a hit for every hacker’s work bench. [Jeremy] used a CNC router to cut the enclosure and top. The plastic top is secured to the MDF base via four 4-40 screws. Interestingly – he applied super glue to the screw holes in the MDF before tapping them. We’ll have to try this trick on our next project!