Building The Electronics For A Tesla Coil… And Watercooling Them

A few years ago [Patrick] was offered the Tesla coil of a friend of a friend. This was an opportunity too good for him to pass up.

He then began the creation of an Off-Line Tesla Coil (OLTC), where no supply transformer is used. The incoming mains supply is rectified and directly fed into the tank capacitor.

[Patrick] therefore had to build a huge capacitor bank and more importantly his own primary coil, made with a 1.6mm (0.064″) copper sheet to handle the immense current involved. Air cooling the electronics was sufficient until he started using his three phase input supply. As more power involves more heat, a waterblock was designed to cool the main transistor.

Patrick’s write-up is very detailed and worth the read. Once you’re finished with it, we advise you to browse through his website, where a lot more cool projects are described.

Tiny WiFi Modules, Again

The CC3000 is a tiny, single-chip component that adds all the necessary hardware (save for a chip antenna) and software to get even the most minimal microcontrollers onto a WiFi network. It was announced early this year but making proper breakout boards takes time, you know? This time has finally arrived with CC3000 modules from Adafruit, and evaluation modules and booster packs from TI themselves.

Unlike other microcontroller-compatible WiFi modules out there, the CC3000 takes care of just about everything – the TCP/IP stack, security stuff, and even the configuration with TI’s SmartConfig app for desktop, laptop, or mobile devices. Realistically, you can get an ATtiny, an exceedingly sparse microcontroller, or even a Commodore 64 or Apple II on the Internet with this. It’s very, very cool.

While these breakout boards and modules are priced very well for what they do, they’re still fairly expensive to stick in a project permanently. Where the CC3000 really shines is including it in your next fabbed board. There are already Altium parts and an Eagle library that includes this part should you need help with that, and blatant advertising for our overlords at SupplyFrame if you’re looking for a source.

A $5 ARM Development Board

Most of you know that there are plenty of ARM powered development boards out there, so you may not be really sure what a new one can still bring to the table.

With a $5 price tag, the open hardware McHck (pronounced McHack) is meant for quickly building projects on a small budget. The board created by [Simon] is based on a Freescale Cortex M4 microcontroller, and can be plugged directly into one’s computer. As a Direct Firmware Update (DFU) bootloader is present on the microcontroller, there is no need for external programming equipment.

The board has unpopulated footprints that allow users to add other functionalities that may be required for their future projects: a Real Time Clock (RTC), a Boost regulator for single cell battery operation, Buck and linear regulators, a Lithium Polymer (LiPo) battery charger and even an External Flash storage.

The Bill of Materials can be found on the project wiki and the McHck community will soon launch a crowdfunding campaign to send the 5th version of the board to all the hobbyists that may be interested.

And if you’re curious, you can also have a look at all the other boards that Hackaday featured these last months: the browser based IDE arm boardquad-core ARM dev board and the Matchbox ARM.

Centimeter-level Precision GPS For $900

[Colin] and [Fergus] have been working with GPS for years now, and like most builders of really cool things, they’re often limited by the precision of off-the-shelf GPS units. While a GPS receiver is usually good for meters of accuracy,  this just isn’t good enough for a lot of projects. What you need is centimeter-level accuracy, something the guys have managed to do with their Piksi GPS receiver.

Where most GPS receivers only look at the data coming from the GPS satellites orbiting overhead, the Piksi uses another technique, real-time kinematics (RTK), to determine the receiver’s location with exacting precision. The basic idea behind RTK is to look at the carrier frequency of the GPS signals at 1575.42 MHz. This frequency has a wavelength of 19 cm, compared to the alternating 1s and 0s of the that are transmitted at around 1 MHz, or about 300 meters between each bit. While centimeter-level precision isn’t possible with only one receiver, two of these Piksi boards – one base station and one on a vehicle, connected via radio link – can make for a very exacting high-accuracy GPS receiver.

Previously, commercial RTK GPS systems have cost thousands of dollars – making a quadcopter or other homebrew project that relies on this level of precision nonsensical. [Colin] and [Fergus] have built hardware that can bring the price of this setup to under $1000. As a bonus, the Piksi board can also receive from other constellations such as Galileo and GLONASS. A very impressive piece of hardware, and we can’t wait to see the applications.

Overclocking Your Bitcoin Miner

The name of the game in mining Bitcoins isn’t CPUs, GPUs, or even FPGAs. Now, hardcore miners are moving on to custom ASIC chips like the Block Erupter, For around $100 USD, you too can mine Bitcoins at 300 MH/s with 2.5 Watts of power and a single USB port. This speed isn’t enough for some people, like [Jeremy] who overclocked his Block Erupter to nearly twice the speed.

[Jeremy] begins his tutorial with a teardown of the Block Erupter hardware. Inside, he found a custom ASIC chip, an ATTIny2313, a USB UART converter, and a voltage regulator for the ASIC. By changing out the 12 MHz crystal connected to the ASIC and fiddling with the voltage with a trim pot, [Jeremy] was able to overclock the ASIC core from 336 MHz to 560 MHz. Effectively, he’s running two Block Eruptors for the price of one with the potential to actually make back the purchase price of his hardware.

It must be noted the 560 MHz figure comes from replacing the 12 MHz crystal with a 20 MHz one, and this mod only lasted about 20 minutes on [Jeremy]’s bench until the magic blue smoke was released. He recommends a 14 or 16 MHz crystal, netting a new speed of either 392 MHz or 448 MHz for a stable mod.

The Mill CPU Architecture

There are basically two ways to compute data. The first is with a DSP, a chip that performs very specialized functions on a limited set of data. These are very cheap, have amazing performance per watt, but can’t do general computation at all. If you’d like to build a general-purpose computer, you’ll have to go with a superscalar processor – an x86, PowerPC, or any one of the other really beefy CPU architectures out there. Superscalars are great for general purpose computing, but their performance per watt dollar is abysmal in comparison to a DSP.

A lot of people have looked into this problem and have come up with nothing. This may change, though, if [Ivan Godard] of Out-of-the-Box computing is able to produce The Mill – a ground-up rethink of current CPU architectures.

Unlike DSPs, superscalar processors you’d find in your desktop have an enormous amount of registers, and most of these are rename registers, or places where the CPU stores a value temporarily. Combine this with the fact that connecting hundreds of these temporary registers to places where they’ll eventually be used eats up about half the power budget in a CPU, and you’ll see why DSPs are so much more efficient than the x86 sitting in your laptop.

[Ivan]’s solution to this problem is replacing the registers in a CPU with something called a ‘belt’ – basically a weird combination of a stack and a shift register. The CPU can take data from any position on the belt, perform an operation, and places the result at the front of the belt. Any data that isn’t used simply falls off the belt; this isn’t a problem, as most data used in a CPU is used only once.

On paper, it’s a vastly more efficient means of general purpose computation. Unfortunately, [Ivan] doesn’t quite have all the patents in for The Mill, so his talks (two available below) are a little compartmentalized. Still, it’s one of the coolest advances in computer architecture in recent memory and something we’d love to see become a real product.

Continue reading “The Mill CPU Architecture”

Geometry Class Just Got Augmented

ruler

Just about every engineer needs to take a drawing class, but until now we surprisingly haven’t seen electronics thrown into rulers, t-squares, and lead holders. [Anirudh] decided to change that with Glassified. It’s a transparent display embedded in a ruler that is able to capture hand drawn lines. These physical lines can be interacted with or measured, turning a ruler into a bridge between a paper drawing and a digital environment.

For the display, [Anirudh] mounted a transparent TOLED display with a digitizer input into a ruler. The digitizer captures the pen strokes underneath the ruler, and is able to interact with the physical lines, either to calculate the length and angle of lines, or just to bounce a digital ball inside a hand-drawn polygon.

There’s no word on how this display is being driven, or what kind of code is running on it. [Anirudh] said he will have some schematics and code available up on his website soon (it’s a 404 right now).