Going Lo-Tech For The Perfect Pokemon Go Throw

We have our eyes on the horizon for an epic GPS spoof to catch some legendaries in Pokemon Go, but until that hack shows up, we really like [Brian McEvoy’s] hack for the perfect Poke Ball throw.

[Brian] started out thinking that a mechanical build would be the best way (we know he’s got the servo motors and controllers to drive them from this tea steeping robot he built last year). But the mechanics of that are just too complicated for what you get in return (less wasted Poke Balls).

He came to the realization that your finger is the best machine, it just needs some augmentation. Most of his Poke Ball throws missed to one side or another, so he turned to papercraft to guide his way. He made a tray from some paperboard packaging, then used two small stacks of Post-it notes to create a channel where your finger slides. Simply hold the phone and the paper with one hand, and use your other to follow the paper channel to a successful capture. The paperboard doesn’t affect the screen’s ability to sense your finger.

This is one we’re definitely going to try out. But visions of hardware hacks for the game that has rocked the world still dance through our heads. Are you working on anything? If so, we’d love to hear about (so send in a tip!). Those still in the idea phase can ring in below. We are weighing the feasibility of doing a man-in-the-middle between a phone and its GPS chip to spoof location. That feels like a pretty tall mountain to climb.

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Build Your Own Brushless Motor

Building an electric motor from a coil of wire, some magnets, and some paper clips is a rite of passage for many budding science buffs. These motors are simple brushed motors. That is, the electromagnet spins towards a permanent magnet and the spinning breaks the circuit, allowing the electromagnet to continue spinning from inertia. Eventually, the connection completes again and the cycle starts over. Real brushed motors commutate the DC supply current so that the electromagnet changes polarity midway through the turn. Either way, the basic design is permanent magnets on the outside (the stationary part) and electromagnets on the inside (the rotating part).

Brushless motors flip this inside out. The rotating part (the rotor) has a permanent magnet. The stationary part (the stator) has multiple electromagnets. By controlling the electromagnets, the rotor spins. With no brushes, these motors are often more efficient, they don’t generate as much electrical noise, and there is no danger of brushes wearing out. In addition, the electromagnets staying put make the motor easier to wire and, if needed, easier to cool the electromagnets. The principle of operation is similar to a stepper motor. Steppers are usually optimized for small precise steps. Brushless motors are optimized for spinning, not stepping.

[Axbm] built a clever brushless motor out of little more than PVC pipe, some magnets, wire, and iron rods. The plan is simple: construct a PVC frame, build a rotor out of PVC and magnets, and mount electromagnets on the frame. An Arduino and some FETs drive the coils, although you could drive the motors using any number of methods. You can see the whole thing work in the video below.

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Expanding Horizons With The Ion Propelled Lifter

Like many people, going through university followed an intense career building period was a dry spell in terms of making things. Of course things settled down and I finally broke that dry spell to work on what I called “non-conventional propulsion”.

I wanted to stay away from the term “anti-gravity” because I was enough of a science nut to know that such a thing was dubious. But I also suspected that there might be science principles yet to be discovered. I was willing to give it a try anyway, and did for a few years. It was also my introduction to the world of high voltage… DC. Everything came out null though, meaning that any effects could be accounted for by some form of ionization or Coulomb force. At no time did I get anything to actually fly, though there was a lot of spinning things on rotors or weight changes on scales and balances due to ion propulsion.

So when a video appeared in 2001 from a small company called Transdimensional Technologies of a triangle shaped, aluminum foil and wire thing called a lifter that actually propelled itself off the table, I immediately had to make one. I’d had enough background by then to be confident that it was flying using ion propulsion. And in fact, given my background I was able to put an enhancement in my first version that others came up with only later.

For those who’ve never seen a lifter, it’s extremely simple. Think of it as a very leaky capacitor. One electrode is an aluminum foil skirt, in the shape of a triangle. Spaced apart from that around an inch or so away, usually using 1/6″ balsa wood sticks, is a very thin bare wire (think 30AWG) also shaped as a triangle. High voltage is applied between the foil skirt and the wire. The result is that a downward jet of air is created around and through the middle of the triangle and the lifter flies up off the table. But that is just the barest explanation of how it works. We must go deeper!

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DIYing Huge BGA Packages

One day [Andy] was cruising around eBay and spotted something interesting. Forty Virtex-E FPGAs for two quid each. These are the big boys of the FPGA world, with 512 user IO pins, almost 200,000 logic gates, packed into a 676-ball BGA package. These are not chips designed for the hobbyist. These chips are not designed for boards with less than six layers. These chips aren’t even designed for boards with 6/6mil tolerances from the usual suspects in China. By any account, a 676-ball package is not like a big keep out sign for hobbyists. You don’t turn down a £2 class in advanced PCB design, though, leading to one of the most impressive ‘I just bought some crap on eBay’ projects we’ve seen.

halfbuiltThe project [Andy] had in mind for these chips was a generic dev board, which meant breaking out the IO pins and connecting some SRAM, SDRAM, and Flash memory. The first issue with this project is escape routing all the balls. Xilinx published a handy application note that recommends specific design parameters for the traces of copper under the chip. Unfortunately, this was a six-layer board, and the design rules in the application note were for 5/5mil traces. [Andy]’s board house can’t do six-layer boards, and their design rules are for 6/6mil traces. To solve this problem, [Andy] just didn’t route the inner balls, and hoped the 5mil traces would work out.

With 676 tiny little pads on a PCB, the clocks routed, power supply implemented, too many decoupling caps on the back, differential pairs, static RAM, a few LEDs placed just for fun, [Andy] had to solder this thing up. Since the FPGA was oddly one of the less expensive items on the BOM, he soldered that first, just to see if it would work. It did, which meant it was time to place the RAM, Flash, and dozens of decoupling caps. Everything went relatively smoothly – the only problem was the tiny 0402 decoupling caps on the back of the board. This was, by far, the hardest part of the board to solder. [Andy] only managed to get most of the decoupling caps on with a hot air gun. That was good enough to bring the board up, but he’ll have to figure some other way of soldering those caps for the other 30 or so boards.

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Gremlins Are Air To Air Drones

If you are like most people, your drone flights start on the ground and end either on the ground or–in more cases than most of us want to admit–in a tree. Earlier this year, DARPA awarded initial contracts for the Gremlins program. The idea is to produce unmanned aircraft that can launch from another aircraft and then later have another aircraft recover it.

The idea is to allow a plane to launch an unmanned sensor, for example, while out of range of enemy fire. Later another aircraft can retrieve the drone where a ground crew would get it ready for another flight within 24 hours. An aircraft facing missile fire could unleash a swarm of drones, confusing attackers. The drones have a limited life of about twenty flights, allowing for inexpensive airframes that use existing technology. You can see a concept video from DARPA about how air-launched drones might play a role in future air combat below.

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