Mikey, The Robot That Charges Itself

May 19, 2014 by 21 Comments

 

mikey-the-robot

Mikey is [Mike’s] autonomous robot. Like any good father, he’s given the robot his name. Mikey is an Arduino based robot, which uses a Pixy camera for vision.

[Mike] started with a common 4WD robot platform. He added an Arduino Uno, a motor controller, and a Pixy. The Pixy sends directions to the Arduino via a serial link. Mikey’s original task was driving around and finding frogs on the floor. Since then, [Mike] has found a higher calling for Mikey: self charging.

One of the most basic features of life is eating. In the case of autonomous robots, that means self charging. [Mike] gave Mikey the ability to self charge by training the Pixy to detect a green square. The green square identifies Mikey’s charging station. Probes mounted on 3D printed brackets hold the positive leads while springs on the base of the station make contact with conductive tape on Mikey’s belly. Once the circuit is complete, Mike stops moving and starts charging.

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Youthful Destruction At Maker Faire

May 19, 2014 by 28 Comments

[youtube=https://www.youtube.com/watch?v=FLmHTfi13dM&w=580]

 

Who didn’t get in trouble for taking things apart as a kid? The TakeItApart booth at the 2014 Maker Faire was among my favorite. It let anyone (especially the kids) grab a piece of electronics headed for recycling and crack it open just to see what is inside. The good news being that you didn’t need to be able to put it back together again since it’s just going to be ground up for its constituent materials anyway.

There’s something cathartic about watching a 7-year-old stabbing at a Walkman radio with a slotted screwdriver (those plastic cases are more robust than you might think). I asked if anyone had managed to slice open their hand back-to-the-future style in the process and thankfully the answer was no. But there was at least one instance of “free daycare” where the parents wandered off — there are plenty of distractions at MF — much to the chagrin of their progeny.

Seeing this made me think of this recent interview with [Bunnie Huang] in which he mentions taking chips out of their sockets on an Apple II when he was a kid. He would pull them and replace them backwards to see what effect it would have. Ha! If you have a similar childhood experience to share we’d love to hear about it in the comments. If you just want to see the guts of a bunch of stuff head of to TakeItApart.

An Experiment To Test Radioactive Decay Varying Over Time

May 19, 2014 by 64 Comments

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Here’s a hypothesis for you: radioactive decay varies over time, possibly with a yearly cycle. [Panteltje] decided to test this hypothesis, and so far has two year’s worth of data to comb over.

Radioactive decay can be easily detected with a photomultiplier tube, but these tubes are sensitive to magnetic fields and cosmic rays that would easily fly through just about any shielding [Pantelje] could come up with. Instead, the radiation in this setup is detected with simple photo detectors, pressed right up against a tritium-filled glass ampoule, a somewhat common lighting solution for fishing lures, watch faces, and compasses.

The experimental setup records the photo detectors, a temperature sensor, and a voltage reference, recording all the data to an EEPROM once an hour. All the important electronics are stuffed into a heatsinked, insulated, light-proof box, while the control electronics reside on a larger board with battery backup, alarm, indicator LEDs, and an RS232 connection.

After one year, [Pantelje] recorded the data and reset the experiment for another year. There are now two years worth of data available, ready for anyone to analyze. Of course, evidence that radioactive decay changes over the course of a few years would turn just about every scientific discipline on its head, so at the very least [Panteltje] has a great record of the output of tritium lights against the expected half-life.

Pokemon Artificial Intellegence

Pokemon Artificial Intelligence Is Smarter Than You

May 19, 2014 by 12 Comments

Who out there hasn’t angrily thrown a game controller across the room after continually getting killed by some stupid game-controlled villain? That is such a bummer! You probably wished there was some way to ‘just get past that point’. To take a step in that direction, [Ben] created an Artificial Intelligence program that will win at Pokemon Blue for Game Boy Advance.

The game is run in a Game Boy Advance emulator known as Visual Boy Tracer, which itself is a modified version of the most common GBA emulator, Visual Boy Advance. What sets Visual Boy Advance apart from the rest is that it has a memory dump feature which allows the user to send both the RAM and the ROM out of the emulator. The RAM holds all values currently needed by the emulator, this includes everything from text arrow flash times to details about currently battling Pokemon to the players position in the currently loaded map. The memory dump feature is key to allow the AI to understand what is happening in the game.

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Driving 1000 NeoPixels With 1k Of Arduino RAM

May 19, 2014 by 36 Comments

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NeoPixels, or WS2812 RGB LEDs, are the display device du jour for impressive and blinding lighting projects. Commonly known for very tight timing requirements, [Josh] discovered this is, in fact, usually unnecessary. The timing requirements for NeoPixels aren’t as bad as they seem, once you get to know them.

The official WS2812 timing specs give values that are fairly constraining for anyone writing a library to drive these RGB LED pixels, but simplifying the timing diagram by assuming a 50% duty cycle on the data lines and ignoring the longer maximum times results in a surprising conclusion: the only tight timing parameter for NeoPixel signaling is the maximum width of the 0-bit pulse.

Realizing this, [Josh] wrote a simple demo program to drive over 1000 NeoPixels – an 11 meter long strip – using 1K of RAM on an Arduino. The trick comes by simply delaying the bitbanging a set number of cycles. No obtuse assembly required.

There is only one problem with [Josh]’s method of driving a nearly unlimited amount of NeoPixels – building a display where every NeoPixel is an element in a larger image, such as in a video display, is impossible on systems with limited amounts of RAM. The code writes values to the NeoPixel strip algorithmically, so if you can’t build your animation with for loops, you’re out of luck. Still, Driving this many NeoPixels is a migraine trigger, and we have to give [Josh] credit for doing this with 1K of RAM.

Check out the video of [Josh]’s extreme NeoPixel strip below.

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Solar-Powered Mosquito Birth Control Is Making Waves

May 18, 2014 by 81 Comments

Mosquitoes really suck. Joking aside, they spread dangerous and deadly diseases like Malaria, Dengue and West Nile. They like to breed in pools of stagnant water which can be difficult to keep up with. From egg-laying to larval development, still water is vital for breeding mosquitoes. Instructables user [Gallactronics] hypothesized that disrupting the surface tension of potential nurseries was the key to discouraging breeding, and he built a solar-powered device for under $10 that proves his theory.

There are a few standard ways of dealing with standing water. Someone can keep it drained or it can be sprayed with pesticides. By aerating the water, mosquito mothers are far less likely to successfully arrange their eggs on the surface. Even if the eggs take, the turbulent water surface will suffocate the larvae.

This bubbler ticks all the boxes. It starts as soon as it comes in contact with water and sounds a piezo alarm when the pool has dried or when someone removes it. It runs for 10 minutes at 10-minute intervals using a 555 timer and some transistors. The water probes are stainless steel bolts, and it runs on a 6V 450mA solar cell. Be sure to watch the demonstration below.

We love to see this kind of ingenuity and elegance in problem solving. Then again, we also like the idea of killing them with lasers.

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Emulating Touchscreens In Python

May 18, 2014 by 11 Comments

DOS

Software, especially DOS-based software meant for CNC control lasts forever, but hardware most certainly does not. When faced with aged and decrepit hardware meant for controlling a CNC machine that was slowly dying, [Oliver] needed something that would emulate 3M Microtouch touchscreen. Not wanting to go the hardware route, he decided to emulate a touch screen in Python.

The Python code is fairly simple, taking mouse input and translating it to the serial protocol the 3M Microtouch, and thus the old DOS CNC app, uses. Writing the Python to capture mouse clicks was only half of the problem, though. [Oliver] also needed a way to send these mouse clicks to an old DOS application. Virtualizing an old machine running DOS created a few timing problems, but a solution was eventually found with DOSBox and the Virtual Serial Port Emulator that can connect two applications with serial ports.

[Oliver] was finally able to get everything working, bringing this equipment back to life for at least another 30 years. Let’s just hope all the code is well documented and archived for the next guy.