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Galvanic Isolated FTDI Board Saves Your USB Ports

Isolated FTDI circuitg

We work with some dangerous circuits in the pursuit of cool hacks. High voltage, high current, all demand some respect. We can protect our bodies easily enough, but what about that fancy new laptop or Macbook? [David] is here to help with his isolated versatile FTDI circuit.

Our computers are often wired directly into the circuits we’re hacking on. In days past that might have been a parallel or serial port. Today it’s almost always USB, specifically serial over USB. USB has some safety features built-in, such as current limiting. However, it isn’t too hard to blow up a USB port, or even a motherboard with high voltage. Galvanic isolation is a method of removing any electrical connection between two circuits. Connections can still be made through optical, magnetic, or capacitive methods, just to name a few. One of the simplest methods of galvanic isolation is the humble optocoupler.

Isolating a high-speed USB connection can get somewhat complex. [David] wisely chose to isolate things on the serial side of the FTDI USB to serial converter. He started with SparkFun’s open source FTDI Basic Breakout. Galvanic isolation is through either an Analog Devices ADuM 1402 or ADuM 5402. The 1402 needs a bit of power on the isolated side, while the 5402 includes an isolated DC/DC converter to provide up to 60mA.

[David] didn’t just stop at galvanic isolation. He also added ESD protection, over current protection, and multiple options which can be selected when the board is built. Nice work [David]! Now we don’t have to worry about our laptop frying when we’re blowing up wires.

Playing Tetris on an Oscilloscope

Tetris on an oscilloscope

Have engineers stopped putting Easter eggs into technology lately? It’s always been a fun way to connect with your more advanced customer base (i.e. hackers) — anyway, here’s a great Easter egg you can find on the Hewlett Packard 54600B Oscilloscop — Tetris!

[RaffttaM] discovered this trick when a coworker let him know that one of the oscilloscopes in the lab had the hidden feature. A little fiddling later and a game of Tetris was revealed. If you press the Print/Utility button on the 54600B oscilloscope, followed by pressing the second and third button below the screen at the same time, you can launch the game!

Another cool embedded Easter egg is in the Game Boy Printer — If you hold the feed button during power up it spits out a Mario themed image! One of our readers even managed to hack the printer to show the Hack a Day Logo instead!

Do you know of any more modern tech with cool (and sneaky!) Easter eggs? Let us know by sending in a tip!

[Thanks Gregory!]

Measuring Light With ChipKIT

light meter showing LUX value

How does one go about measuring the amount of light in a given area? With a Light Meter of course! Maintaining proper lighting levels can be very important in places like schools, hospitals and even your own workbench.

[Raj] over at Embedded Labs has put together an excellent tutorial on how to construct your very own light meter based upon the chipKIT platform. The chipKIT Uno32 is similar to Arduino, but boasts a much more powerful PIC32MX320F128 microcontroller.  We’ve seen projects that feature the chipKIT Uno (pdf warning) here before. From playing pong to hosting several temperature sensors, it’s certainly a versatile platform.

The light meter uses an I/O shield and communicates to a BH1750FVI digital light sensor via I2C. The firmware divides the raw data coming off the sensor by a constant, and displays the light intensity data on an OLED display in Lux, foot-candles, and Watts/m^2 units. Be sure to check out the tutorial for full schematics and source.

Self-Learning Helicopter Uses Neural Network

model helicopter attached to boom

Though this project uses an RC helicopter, it’s merely a vessel to demonstrate a fascinating machine learning algorithm developed by two Cornell students – [Akshay] and [Sergio]. The learning environment is set up with the helicopter at its center, attached to a boom. The boom restricts the helicopter’s movement down to one degree of motion, so that it can only move up from the ground (not side to side or front to back).

The goal is for the helicopter to teach itself how to get to a specific height in the quickest amount of time. A handful of IR sensors are used to tell the Atmega644 how high the helicopter is. The genius of this though, is in the firmware. [Akshay] and [Sergio] are using an evolutionary algorithm adopted from Floreano et al, a noted author on biological inspired artificial intelligences. The idea is for the helicopter to create random “runs” and then check the data. The runs that are closer to the goal get refined while the others are eliminated, thus mimicking evolutions’ natural selection.

We’ve seen neural networks before, but nothing like this. Stay with us after the break, as we take this awesome project and narrow it down so that you too can implement this type of algorithm in your next project.


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The Computer Without A CPU


[Jeff Laughton] was contacted by a customer that was interested in adding some automated functions to a printing press. Before eventually settling on a microcontroller for the job, [Jeff] went old school and started looking at logic gates, counters, and flip-flops. This lead him to the Motorola 14500 industrial control unit, a minimal processor with only 16 instructions. After a few ‘back of the napkin’ sketches, he came up with an extremely minimal computer that doesn’t use a microprocessor. It’s an interesting design notable not only for its electronic brevity, but also because it only uses one instruction.

The only instruction this computer will ever execute is an input test, the result of which controls a two-way branch. Instructions consist of an input address, output address, and a single bit of data. If the data bit is true, the computer jumps to one location in ROM, and if the data bit is false, a jump to another location is executed.

A computer really isn’t a computer without some form of memory, and this design is no exception. [Jeff] managed to add two bits of data between the 8-bit latch and 8-bit multiplexer in the design. This is enough to call a few subroutines which test the I/O-mapped memory to decide what the next instruction should be.

It’s a truly bizarre design, but actually much closer to a true Turing machine than the computers in your pocket, on your wrist, on your desk, and in your car.

Thanks [James] for the tip!


The Pyro Board: A Two Dimensional Ruben’s Tube



Like visualizing music? Love fire? If so, you’re going to want to take a look at this Pyro Board.

What happens when you take a tube, put some holes along it, add a speaker on one end, pump some propane in, and then light it on fire? You get an awesome fire visual – also known as a Ruben’s Tube. It works because the sound pressure from the speakers causes the flow rate of gas leaving the holes to vary, which results in a visible “standing frequency” of flames, i.e. a flaming VU meter.

The folks over at [Fysikshow] decided to step it up a notch by building a 2-dimensional Ruben’s tube with 2500 holes. They have a steel box with the evenly spaced holes on the top, and two speakers attached to the sides. And it works amazingly well — see for yourself after the break.

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Homemade Gravity Light Doesn’t Last Long but Proves the Concept!

gravity light

After being inspired by the Deciwatt Gravity light, [Steve Dufresne] decided he wanted to try making his own as a proof of concept.

The Gravity Light by Deciwatt is an innovative device designed for third world countries to help eliminate expensive lighting like kerosene lamps. It has a small weight on a pulley which can be lifted up in under 3 seconds. During its slow descent down the weight provides light for 25 minutes! It’s affordable, sustainable, and reliable. It’s also mechanically impressive, which is exactly why [Steve] decided to try making his own.

He’s using a single LED, a small DC motor, a few pieces of wood, an old bicycle wheel, some bicycle chain, and a few jugs of water. The water is connected to the chain which is looped over the smallest gear on the bike. The generator is then powered by a belt wrapping around the outside of the rim. This gives the motor enough speed to generate electricity for the LED. His current design only lasts for about 3 minutes, but he’s already working on the second iteration. Testing systems like this really give you an appreciation for the effort that must have gone into the real Gravity Light.

Stick around after the break to see it in action.

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