Reverse-Engineering a Superior Chinese Product

It makes an Arduino look like a 555.  A 364 Mhz, 32 bit processor. 8 MB RAM. GSM. Bluetooth. LCD controller. PWM. USB and dozens more. Smaller than a Zippo and thinner than corrugated cardboard. And here is the kicker: $3. So why isn’t everyone using it? They can’t.

Adoption would mandate tier after tier of hacks just to figure out what exact hardware is there. Try to buy one and find that suppliers close their doors to foreigners. Try to use one, and only hints of incomplete documentation will be found. Is the problem patents? No, not really.

[Bunnie] has dubbed the phenomenon “Gongkai”, a type of institutionalized, collaborative, infringementesque knowledge-exchange that occupies an IP equivalent of bartering. Not quite open source, not quite proprietary. Legally, this sharing is only grey-market on paper, but widespread and quasi-accepted in practice – even among the rights holders. [Bunnie] figures it is just the way business is done in the East and it is a way that is encouraging innovation by knocking down barriers to entry. Chinese startups can churn out gimmicky trash almost on whim, using hardware most of us could only dream about for a serious project.

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Selfie-Bots Will Take Your Best Shots For You

Professor [Bruce Land] teaches a microcontroller class at Cornell University, and it seems like this year’s theme was selfie-taking-robots.

First up is a clever mix of technology by [Han, Bihan and Chuan]. What happens when you take an iPhone, three microphones and a microcontroller? The ultimate device in selfie-taking-technology, that’s what — Clap-on! The iPhone is mounted on a few servo motors which allows the bot to direct the camera towards, you guessed it, a clapping noise. On the second clap, the phone takes your picture. Cute.

Next up is a bit more sophisticated — a facial recognition selfie-bot. This little robot can be programmed to track faces and take pictures of you and your friends when your arm is just not long enough. Not only that, you can set all kinds of parameters so you get the perfect picture. It uses OpenCV to crunch the raw data and outputs commands to an ATmega1284 which controls the servo motors that direct the camera. This project was by [Michael and Jennifer] — two fourth year students at Cornell.

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PeriUSBoost: A DIY USB Battery Pack

If you travel often, use your mobile devices a lot, or run questionable ROMs on your phone, you likely have an external USB battery pack. These handy devices let you give a phone, tablet, or USB powered air humidifier (yes, those exist) some extra juice.

[Pedro]’s PeriUSBoost is a DIY phone charging solution. It’s a switching regulator that can boost battery voltages up to the 5 volt USB standard. This is accomplished using the LTC3426, a DC/DC converter with a built in switching element. The IC is a tiny SOT-23 package, and requires a few external passives work.

One interesting detail of USB charging is the resistor configuration on the USB data lines. These tell the device how much current can be drawn from the charger. For this device, the resistors are chosen to set the charge current to 0.5 A.

While a 0.5 A charge current isn’t exactly fast, it does allow for charging off AA batteries. [Pedro]’s testing resulted in a fully charged phone off of two AA batteries, but they did get a bit toasty while powering the device. It might not be the best device to stick in your pocket, but it gets the job done.

Using the Wrong Screw: A Painful Lesson in iPhone Repair

If you’ve ever had to repair an iPhone for a friend, you’ll know they have a ridiculous number of screws. Most companies standardize screws in their products, but since Apple doesn’t expect you to fix a phone yourself… they may have let this one slide.

You see, each of these screws is different.iPhone screws The red ones are 1.7mm long, the yellow one, 1.3mm, and the orange one, 1.2mm.

Guess what happens if you install either red or yellow screws into the orange spot, since your eyesight isn’t good enough to notice a 0.1mm difference? The screw will cut into the PCB and break several 50 micron traces, as shown in the picture above, causing a blue screen error on the phone.

Fun stuff.

[Sam Schmidt] is the owner of a repair outfit called iRepairNational, and he and his team spent a day trying to figure out the problem – it’s not exactly easy to spot. They’ve managed to repair it by cutting thin strips  of copper foil (the width of a human hair) and floating it into place using the surface tension of the flux they were using for soldering. On average it takes them around 2 hours to do the repair, though they’ve done a few in just under an hour.

Since discovering and sharing the problem, they’ve had customers around the world sending in phones for repair – often at the fault of someone else trying to repair something completely different in the phone, and then using the wrong screw as they put it all back together.

Estimating BB Gun Muzzle Velocity with a Voice Recorder and a Curtain


[Luke Wren] just wrote in to tell us about his new science blog called Wren’s Tech — it’s only a few days old, but he’s already got some pretty cool science experiments written up! Like how to estimate the muzzle velocity of a BB gun using just a voice recorder, and a curtain!

There are many different ways you could do this. One of the easiest is using a high-speed camera with a known grid or pattern as the background — like how Mythbusters does it. Unfortunately, high-speed cameras are usually out of reach for most hobbyists. [Luke] explains a rather cool system you can build with some electronics, whereby you have two thin wires a known distance apart — run current through both and use a circuit that can detect the interrupt as your projectile breaks the wires — or, you can use a voice recorder. Continue reading “Estimating BB Gun Muzzle Velocity with a Voice Recorder and a Curtain”

Pwning Timberman with Electronically Simulated Touchscreen Presses


What do you do if you suck at a smartphone game? Buy some in-game upgrades to pretend like you’re good? Screw that! [Valentin] did what any self-respecting hacker would: developed an automated system to play for him.

Granted, when you see the demo video embedded below you’ll realize there isn’t much strategy involved in this game. But that setup to simulate the touchscreen presses is pretty neat. We’re used to seeing mechanical touchscreen hacks but this one is electronic, using a couple of pads of copper foil tape and some relays to make it happen. Here’s the one caveat: you still need to be touching something with your hand. This just uses the relays to switch the connection between the pads and your body.

We’ve looked around for this before. Does anyone have a cheap, simple, and effective hack to fully automate presses on a modern touchscreen? Can we use a potato or something? Tell us below, but send it in to the tips line too!

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Embedding Wireless Charging into Your Laptop

Wireless charger in chromebook

Looking for a project to do [Jason Clark] thought it might be fun to integrate a spare wireless Qi charger into his HP Chromebook 14.

He started by cracking open the Qi charger — it’s held together by adhesive and four phillips screws hiding under the feet pads — all in all, not that difficult to do. Once the plastic is off, the circuit and coil are actually quite small making it an ideal choice for hacking into various things. We’ve seen them stuffed into Nook’s, a heart, salvaged for a phone hack…

Anyway, the next step was opening up the Chromebook. The Qi charger requires 5V at 2A to work, which luckily, is the USB 3.0 spec — of which he has two ports in the Chromebook. He identified the 5V supply on the board and soldered in the wires directly —  Let there be power!

While the coil and board are fairly small, there’s not that much space underneath the Chromebook’s skin, so [Jason] lengthened the coil wires and located it separately, just below the keyboard. He closed everything up, crossed his fingers and turned the power on. Success!

It’d be cool to do something similar with an RFID reader — then you could have your laptop locked unless you have your RFID ring with you!